rfc2518.txt   draft-ietf-webdav-rfc2518bis-latest.txt 
Network Working Group Y. Goland WebDAV Working Group L. Dusseault, Ed.
Request for Comments: 2518 Microsoft Internet-Draft CommerceNet
Category: Standards Track E. Whitehead Obsoletes: 2518 (if approved) February 15, 2007
UC Irvine Intended status: Standards Track
A. Faizi Expires: August 19, 2007
Netscape
S. Carter
D. Jensen
Novell
February 1999
HTTP Extensions for Distributed Authoring -- WEBDAV HTTP Extensions for Distributed Authoring - WebDAV
draft-ietf-webdav-rfc2518bis-18
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Abstract Abstract
This document specifies a set of methods, headers, and content-types WebDAV consists of a set of methods, headers, and content-types
ancillary to HTTP/1.1 for the management of resource properties, ancillary to HTTP/1.1 for the management of resource properties,
creation and management of resource collections, namespace creation and management of resource collections, URL namespace
manipulation, and resource locking (collision avoidance). manipulation, and resource locking (collision avoidance).
Table of Contents RFC2518 was published in February 1999, and this specification makes
minor revisions mostly due to interoperability experience.
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 6 Table of Contents
2. Notational Conventions . . . . . . . . . . . . . . . . . . . 7
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 7
4. Data Model for Resource Properties . . . . . . . . . . . . . 8
4.1. The Resource Property Model . . . . . . . . . . . . . . 8
4.2. Existing Metadata Proposals . . . . . . . . . . . . . . 9
4.3. Properties and HTTP Headers . . . . . . . . . . . . . . 9
4.4. Property Values . . . . . . . . . . . . . . . . . . . . 10
4.5. Property Names . . . . . . . . . . . . . . . . . . . . . 10
4.6. Media Independent Links . . . . . . . . . . . . . . . . 11
5. Collections of Web Resources . . . . . . . . . . . . . . . . 11
5.1. HTTP URL Namespace Model . . . . . . . . . . . . . . . . 11
5.2. Collection Resources . . . . . . . . . . . . . . . . . . 11
5.3. Creation and Retrieval of Collection Resources . . . . . 13
5.4. Source Resources and Output Resources . . . . . . . . . 13
6. Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.1. Exclusive Vs. Shared Locks . . . . . . . . . . . . . . . 15
6.2. Required Support . . . . . . . . . . . . . . . . . . . . 16
6.3. Lock Tokens . . . . . . . . . . . . . . . . . . . . . . 16
6.4. opaquelocktoken Lock Token URI Scheme . . . . . . . . . 16
6.4.1. Node Field Generation Without the IEEE 802 Address . 17
6.5. Lock Capability Discovery . . . . . . . . . . . . . . . 19
6.6. Active Lock Discovery . . . . . . . . . . . . . . . . . 19
6.7. Usage Considerations . . . . . . . . . . . . . . . . . . 20
7. Write Lock . . . . . . . . . . . . . . . . . . . . . . . . . 21
7.1. Methods Restricted by Write Locks . . . . . . . . . . . 21
7.2. Write Locks and Lock Tokens . . . . . . . . . . . . . . 21
7.3. Write Locks and Properties . . . . . . . . . . . . . . . 21
7.4. Write Locks and Null Resources . . . . . . . . . . . . . 21
7.5. Write Locks and Collections . . . . . . . . . . . . . . 22
7.6. Write Locks and the If Request Header . . . . . . . . . 22
7.6.1. Example - Write Lock . . . . . . . . . . . . . . . . 23
7.7. Write Locks and COPY/MOVE . . . . . . . . . . . . . . . 23
7.8. Refreshing Write Locks . . . . . . . . . . . . . . . . . 24
8. HTTP Methods for Distributed Authoring . . . . . . . . . . . 24
8.1. PROPFIND . . . . . . . . . . . . . . . . . . . . . . . . 24
8.1.1. Example - Retrieving Named Properties . . . . . . . 26
8.1.2. Example - Using allprop to Retrieve All Properties . 28
8.1.3. Example - Using propname to Retrieve all Property
Names . . . . . . . . . . . . . . . . . . . . . . . 31
8.2. PROPPATCH . . . . . . . . . . . . . . . . . . . . . . . 33
8.2.1. Status Codes for use with 207 (Multi-Status) . . . . 33
8.2.2. Example - PROPPATCH . . . . . . . . . . . . . . . . 34
8.3. MKCOL Method . . . . . . . . . . . . . . . . . . . . . . 35
8.3.1. Request . . . . . . . . . . . . . . . . . . . . . . 35
8.3.2. Status Codes . . . . . . . . . . . . . . . . . . . . 36
8.3.3. Example - MKCOL . . . . . . . . . . . . . . . . . . 36
8.4. GET, HEAD for Collections . . . . . . . . . . . . . . . 37
8.5. POST for Collections . . . . . . . . . . . . . . . . . . 37
8.6. DELETE . . . . . . . . . . . . . . . . . . . . . . . . . 37
8.6.1. DELETE for Non-Collection Resources . . . . . . . . 37
8.6.2. DELETE for Collections . . . . . . . . . . . . . . . 37
8.7. PUT . . . . . . . . . . . . . . . . . . . . . . . . . . 39
8.7.1. PUT for Non-Collection Resources . . . . . . . . . . 39
8.7.2. PUT for Collections . . . . . . . . . . . . . . . . 39
8.8. COPY Method . . . . . . . . . . . . . . . . . . . . . . 39
8.8.1. COPY for HTTP/1.1 resources . . . . . . . . . . . . 40
8.8.2. COPY for Properties . . . . . . . . . . . . . . . . 40
8.8.3. COPY for Collections . . . . . . . . . . . . . . . . 40
8.8.4. COPY and the Overwrite Header . . . . . . . . . . . 42
8.8.5. Status Codes . . . . . . . . . . . . . . . . . . . . 42
8.8.6. Example - COPY with Overwrite . . . . . . . . . . . 42
8.8.7. Example - COPY with No Overwrite . . . . . . . . . . 43
8.8.8. Example - COPY of a Collection . . . . . . . . . . . 43
8.9. MOVE Method . . . . . . . . . . . . . . . . . . . . . . 44
8.9.1. MOVE for Properties . . . . . . . . . . . . . . . . 45
8.9.2. MOVE for Collections . . . . . . . . . . . . . . . . 45
8.9.3. MOVE and the Overwrite Header . . . . . . . . . . . 46
8.9.4. Status Codes . . . . . . . . . . . . . . . . . . . . 46
8.9.5. Example - MOVE of a Non-Collection . . . . . . . . . 46
8.9.6. Example - MOVE of a Collection . . . . . . . . . . . 47
8.10. LOCK Method . . . . . . . . . . . . . . . . . . . . . . 48
8.10.1. Operation . . . . . . . . . . . . . . . . . . . . . 48
8.10.2. The Effect of Locks on Properties and Collections . 48
8.10.3. Locking Replicated Resources . . . . . . . . . . . . 49
8.10.4. Depth and Locking . . . . . . . . . . . . . . . . . 49
8.10.5. Interaction with other Methods . . . . . . . . . . . 49
8.10.6. Lock Compatibility Table . . . . . . . . . . . . . . 50
8.10.7. Status Codes . . . . . . . . . . . . . . . . . . . . 50
8.10.8. Example - Simple Lock Request . . . . . . . . . . . 51
8.10.9. Example - Refreshing a Write Lock . . . . . . . . . 53
8.10.10. Example - Multi-Resource Lock Request . . . . . . . 54
8.11. UNLOCK Method . . . . . . . . . . . . . . . . . . . . . 55
8.11.1. Example - UNLOCK . . . . . . . . . . . . . . . . . . 55
9. HTTP Headers for Distributed Authoring . . . . . . . . . . . 56
9.1. DAV Header . . . . . . . . . . . . . . . . . . . . . . . 56
9.2. Depth Header . . . . . . . . . . . . . . . . . . . . . . 56
9.3. Destination Header . . . . . . . . . . . . . . . . . . . 57
9.4. If Header . . . . . . . . . . . . . . . . . . . . . . . 57
9.4.1. No-tag-list Production . . . . . . . . . . . . . . . 58
9.4.2. Tagged-list Production . . . . . . . . . . . . . . . 58
9.4.3. not Production . . . . . . . . . . . . . . . . . . . 59
9.4.4. Matching Function . . . . . . . . . . . . . . . . . 60
9.4.5. If Header and Non-DAV Compliant Proxies . . . . . . 60
9.5. Lock-Token Header . . . . . . . . . . . . . . . . . . . 60 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 8
9.6. Overwrite Header . . . . . . . . . . . . . . . . . . . . 60 2. Notational Conventions . . . . . . . . . . . . . . . . . . . 10
9.7. Status-URI Response Header . . . . . . . . . . . . . . . 61 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 11
9.8. Timeout Request Header . . . . . . . . . . . . . . . . . 61 4. Data Model for Resource Properties . . . . . . . . . . . . . 13
10. Status Code Extensions to HTTP/1.1 . . . . . . . . . . . . . 62 4.1. The Resource Property Model . . . . . . . . . . . . . . 13
10.1. 102 Processing . . . . . . . . . . . . . . . . . . . . . 62 4.2. Properties and HTTP Headers . . . . . . . . . . . . . . 13
10.2. 207 Multi-Status . . . . . . . . . . . . . . . . . . . . 63 4.3. Property Values . . . . . . . . . . . . . . . . . . . . 13
10.3. 422 Unprocessable Entity . . . . . . . . . . . . . . . . 63 4.3.1. Example - Property with Mixed Content . . . . . . . 15
10.4. 423 Locked . . . . . . . . . . . . . . . . . . . . . . . 63 4.4. Property Names . . . . . . . . . . . . . . . . . . . . . 17
10.5. 424 Failed Dependency . . . . . . . . . . . . . . . . . 63 4.5. Source Resources and Output Resources . . . . . . . . . 17
10.6. 507 Insufficient Storage . . . . . . . . . . . . . . . . 63 5. Collections of Web Resources . . . . . . . . . . . . . . . . 18
11. Multi-Status Response . . . . . . . . . . . . . . . . . . . . 64 5.1. HTTP URL Namespace Model . . . . . . . . . . . . . . . . 18
12. XML Element Definitions . . . . . . . . . . . . . . . . . . . 64 5.2. Collection Resources . . . . . . . . . . . . . . . . . . 18
12.1. activelock XML Element . . . . . . . . . . . . . . . . . 64 6. Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
12.1.1. depth XML Element . . . . . . . . . . . . . . . . . 64 6.1. Lock Model . . . . . . . . . . . . . . . . . . . . . . . 21
12.1.2. locktoken XML Element . . . . . . . . . . . . . . . 65 6.2. Exclusive Vs. Shared Locks . . . . . . . . . . . . . . . 22
12.1.3. timeout XML Element . . . . . . . . . . . . . . . . 65 6.3. Required Support . . . . . . . . . . . . . . . . . . . . 23
12.2. collection XML Element . . . . . . . . . . . . . . . . . 65 6.4. Lock Creator and Privileges . . . . . . . . . . . . . . 23
12.3. href XML Element . . . . . . . . . . . . . . . . . . . . 65 6.5. Lock Tokens . . . . . . . . . . . . . . . . . . . . . . 24
12.4. link XML Element . . . . . . . . . . . . . . . . . . . . 66 6.6. Lock Timeout . . . . . . . . . . . . . . . . . . . . . . 25
12.4.1. dst XML Element . . . . . . . . . . . . . . . . . . 66 6.7. Lock Capability Discovery . . . . . . . . . . . . . . . 25
12.4.2. src XML Element . . . . . . . . . . . . . . . . . . 66 6.8. Active Lock Discovery . . . . . . . . . . . . . . . . . 26
12.5. lockentry XML Element . . . . . . . . . . . . . . . . . 67 7. Write Lock . . . . . . . . . . . . . . . . . . . . . . . . . 27
12.6. lockinfo XML Element . . . . . . . . . . . . . . . . . . 67 7.1. Write Locks and Properties . . . . . . . . . . . . . . . 27
12.7. lockscope XML Element . . . . . . . . . . . . . . . . . 67 7.2. Avoiding Lost Updates . . . . . . . . . . . . . . . . . 28
12.7.1. exclusive XML Element . . . . . . . . . . . . . . . 68 7.3. Write Locks and Unmapped URLs . . . . . . . . . . . . . 29
12.7.2. shared XML Element . . . . . . . . . . . . . . . . . 68 7.4. Write Locks and Collections . . . . . . . . . . . . . . 30
12.8. locktype XML Element . . . . . . . . . . . . . . . . . . 68 7.5. Write Locks and the If Request Header . . . . . . . . . 31
12.8.1. write XML Element . . . . . . . . . . . . . . . . . 68 7.5.1. Example - Write Lock and COPY . . . . . . . . . . . 32
12.9. multistatus XML Element . . . . . . . . . . . . . . . . 69 7.5.2. Example - Deleting a Member of a Locked Collection . 32
12.9.1. response XML Element . . . . . . . . . . . . . . . . 69 7.6. Write Locks and COPY/MOVE . . . . . . . . . . . . . . . 33
12.9.2. responsedescription XML Element . . . . . . . . . . 70 7.7. Refreshing Write Locks . . . . . . . . . . . . . . . . . 34
12.10. owner XML Element . . . . . . . . . . . . . . . . . . . 70 8. General Request and Response Handling . . . . . . . . . . . . 35
12.11. prop XML element . . . . . . . . . . . . . . . . . . . . 71 8.1. Precedence in Error Handling . . . . . . . . . . . . . . 35
12.12. propertybehavior XML element . . . . . . . . . . . . . . 71 8.2. Use of XML . . . . . . . . . . . . . . . . . . . . . . . 35
12.12.1. keepalive XML element . . . . . . . . . . . . . . . 71 8.3. URL Handling . . . . . . . . . . . . . . . . . . . . . . 36
12.12.2. omit XML element . . . . . . . . . . . . . . . . . . 72 8.3.1. Example - Correct URL Handling . . . . . . . . . . . 36
12.13. propertyupdate XML element . . . . . . . . . . . . . . . 72 8.4. Required Bodies in Requests . . . . . . . . . . . . . . 37
12.13.1. remove XML element . . . . . . . . . . . . . . . . . 73 8.5. HTTP Headers for use in WebDAV . . . . . . . . . . . . . 37
12.13.2. set XML element . . . . . . . . . . . . . . . . . . 73 8.6. ETag . . . . . . . . . . . . . . . . . . . . . . . . . . 37
12.14. propfind XML Element . . . . . . . . . . . . . . . . . . 74 8.7. Including Error Response Bodies . . . . . . . . . . . . 38
12.14.1. allprop XML Element . . . . . . . . . . . . . . . . 74 8.8. Impact of Namespace Operations on Cache Validators . . . 38
12.14.2. propname XML Element . . . . . . . . . . . . . . . . 74 9. HTTP Methods for Distributed Authoring . . . . . . . . . . . 40
13. DAV Properties . . . . . . . . . . . . . . . . . . . . . . . 74 9.1. PROPFIND Method . . . . . . . . . . . . . . . . . . . . 40
13.1. creationdate Property . . . . . . . . . . . . . . . . . 75 9.1.1. PROPFIND Status Codes . . . . . . . . . . . . . . . 41
13.2. displayname Property . . . . . . . . . . . . . . . . . . 75 9.1.2. Status Codes for Use in 'propstat' Element . . . . . 42
13.3. getcontentlanguage Property . . . . . . . . . . . . . . 75 9.1.3. Example - Retrieving Named Properties . . . . . . . 42
13.4. getcontentlength Property . . . . . . . . . . . . . . . 76 9.1.4. Example - Using 'propname' to Retrieve All
13.5. getcontenttype Property . . . . . . . . . . . . . . . . 76 Property Names . . . . . . . . . . . . . . . . . . . 44
13.6. getetag Property . . . . . . . . . . . . . . . . . . . . 76 9.1.5. Example - Using So-called 'allprop' . . . . . . . . 46
13.7. getlastmodified Property . . . . . . . . . . . . . . . . 77 9.1.6. Example - Using 'allprop' with 'include' . . . . . . 49
13.8. lockdiscovery Property . . . . . . . . . . . . . . . . . 77 9.2. PROPPATCH Method . . . . . . . . . . . . . . . . . . . . 49
13.8.1. Example - Retrieving the lockdiscovery Property . . 78 9.2.1. Status Codes for Use in 'propstat' Element . . . . . 50
13.9. resourcetype Property . . . . . . . . . . . . . . . . . 79 9.2.2. Example - PROPPATCH . . . . . . . . . . . . . . . . 51
13.10. source Property . . . . . . . . . . . . . . . . . . . . 80 9.3. MKCOL Method . . . . . . . . . . . . . . . . . . . . . . 52
13.10.1. Example - A source Property . . . . . . . . . . . . 80 9.3.1. MKCOL Status Codes . . . . . . . . . . . . . . . . . 53
13.11. supportedlock Property . . . . . . . . . . . . . . . . . 81 9.3.2. Example - MKCOL . . . . . . . . . . . . . . . . . . 53
13.11.1. Example - Retrieving the supportedlock Property . . 81 9.4. GET, HEAD for Collections . . . . . . . . . . . . . . . 54
14. Instructions for Processing XML in DAV . . . . . . . . . . . 82 9.5. POST for Collections . . . . . . . . . . . . . . . . . . 54
15. DAV Compliance Classes . . . . . . . . . . . . . . . . . . . 83 9.6. DELETE Requirements . . . . . . . . . . . . . . . . . . 54
15.1. Class 1 . . . . . . . . . . . . . . . . . . . . . . . . 83 9.6.1. DELETE for Collections . . . . . . . . . . . . . . . 55
15.2. Class 2 . . . . . . . . . . . . . . . . . . . . . . . . 83 9.6.2. Example - DELETE . . . . . . . . . . . . . . . . . . 56
16. Internationalization Considerations . . . . . . . . . . . . . 83 9.7. PUT Requirements . . . . . . . . . . . . . . . . . . . . 56
17. Security Considerations . . . . . . . . . . . . . . . . . . . 85 9.7.1. PUT for Non-Collection Resources . . . . . . . . . . 56
17.1. Authentication of Clients . . . . . . . . . . . . . . . 85 9.7.2. PUT for Collections . . . . . . . . . . . . . . . . 57
17.2. Denial of Service . . . . . . . . . . . . . . . . . . . 86 9.8. COPY Method . . . . . . . . . . . . . . . . . . . . . . 57
17.3. Security through Obscurity . . . . . . . . . . . . . . . 86 9.8.1. COPY for Non-collection Resources . . . . . . . . . 57
17.4. Privacy Issues Connected to Locks . . . . . . . . . . . 86 9.8.2. COPY for Properties . . . . . . . . . . . . . . . . 58
17.5. Privacy Issues Connected to Properties . . . . . . . . . 86 9.8.3. COPY for Collections . . . . . . . . . . . . . . . . 58
17.6. Reduction of Security due to Source Link . . . . . . . . 87 9.8.4. COPY and Overwriting Destination Resources . . . . . 59
17.7. Implications of XML External Entities . . . . . . . . . 87 9.8.5. Status Codes . . . . . . . . . . . . . . . . . . . . 60
17.8. Risks Connected with Lock Tokens . . . . . . . . . . . . 88 9.8.6. Example - COPY with Overwrite . . . . . . . . . . . 61
18. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 88 9.8.7. Example - COPY with No Overwrite . . . . . . . . . . 61
19. Intellectual Property . . . . . . . . . . . . . . . . . . . . 89 9.8.8. Example - COPY of a Collection . . . . . . . . . . . 62
20. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 89 9.9. MOVE Method . . . . . . . . . . . . . . . . . . . . . . 63
21. References . . . . . . . . . . . . . . . . . . . . . . . . . 90 9.9.1. MOVE for Properties . . . . . . . . . . . . . . . . 63
21.1. Normative References . . . . . . . . . . . . . . . . . . 90 9.9.2. MOVE for Collections . . . . . . . . . . . . . . . . 64
21.2. Informational References . . . . . . . . . . . . . . . . 91 9.9.3. MOVE and the Overwrite Header . . . . . . . . . . . 65
Appendix A. Appendices . . . . . . . . . . . . . . . . . . . . . 92 9.9.4. Status Codes . . . . . . . . . . . . . . . . . . . . 65
A.1. Appendix 1 - WebDAV Document Type Definition . . . . . . 92 9.9.5. Example - MOVE of a Non-Collection . . . . . . . . . 66
A.2. Appendix 2 - ISO 8601 Date and Time Profile . . . . . . 94 9.9.6. Example - MOVE of a Collection . . . . . . . . . . . 66
A.3. Appendix 3 - Notes on Processing XML Elements . . . . . 94 9.10. LOCK Method . . . . . . . . . . . . . . . . . . . . . . 67
A.3.1. Notes on Empty XML Elements . . . . . . . . . . . . 94 9.10.1. Creating a Lock on an Existing Resource . . . . . . 67
A.3.2. Notes on Illegal XML Processing . . . . . . . . . . 95 9.10.2. Refreshing Locks . . . . . . . . . . . . . . . . . . 68
A.4. Appendix 4 -- XML Namespaces for WebDAV . . . . . . . . 97 9.10.3. Depth and Locking . . . . . . . . . . . . . . . . . 68
A.4.1. Introduction . . . . . . . . . . . . . . . . . . . . 97 9.10.4. Locking Unmapped URLs . . . . . . . . . . . . . . . 69
A.4.2. Meaning of Qualified Names . . . . . . . . . . . . . 97 9.10.5. Lock Compatibility Table . . . . . . . . . . . . . . 69
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 9.10.6. LOCK Responses . . . . . . . . . . . . . . . . . . . 70
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 102 9.10.7. Example - Simple Lock Request . . . . . . . . . . . 71
Intellectual Property and Copyright Statements . . . . . . . . . 104 9.10.8. Example - Refreshing a Write Lock . . . . . . . . . 73
9.10.9. Example - Multi-Resource Lock Request . . . . . . . 74
9.11. UNLOCK Method . . . . . . . . . . . . . . . . . . . . . 75
9.11.1. Status Codes . . . . . . . . . . . . . . . . . . . . 75
9.11.2. Example - UNLOCK . . . . . . . . . . . . . . . . . . 76
10. HTTP Headers for Distributed Authoring . . . . . . . . . . . 77
10.1. DAV Header . . . . . . . . . . . . . . . . . . . . . . . 77
10.2. Depth Header . . . . . . . . . . . . . . . . . . . . . . 78
10.3. Destination Header . . . . . . . . . . . . . . . . . . . 79
10.4. If Header . . . . . . . . . . . . . . . . . . . . . . . 79
10.4.1. Purpose . . . . . . . . . . . . . . . . . . . . . . 79
10.4.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . 80
10.4.3. List Evaluation . . . . . . . . . . . . . . . . . . 81
10.4.4. Matching State Tokens and ETags . . . . . . . . . . 81
10.4.5. If Header and Non-DAV Aware Proxies . . . . . . . . 82
10.4.6. Example - No-tag Production . . . . . . . . . . . . 82
10.4.7. Example - using "Not" with No-tag Production . . . . 82
10.4.8. Example - causing a Condition to always evaluate
to True . . . . . . . . . . . . . . . . . . . . . . 83
10.4.9. Example - Tagged List If header in COPY . . . . . . 83
10.4.10. Example - Matching lock tokens with collection
locks . . . . . . . . . . . . . . . . . . . . . . . 84
10.4.11. Example - Matching ETags on unmapped URLs . . . . . 84
10.5. Lock-Token Header . . . . . . . . . . . . . . . . . . . 84
10.6. Overwrite Header . . . . . . . . . . . . . . . . . . . . 85
10.7. Timeout Request Header . . . . . . . . . . . . . . . . . 85
11. Status Code Extensions to HTTP/1.1 . . . . . . . . . . . . . 86
11.1. 207 Multi-Status . . . . . . . . . . . . . . . . . . . . 86
11.2. 422 Unprocessable Entity . . . . . . . . . . . . . . . . 86
11.3. 423 Locked . . . . . . . . . . . . . . . . . . . . . . . 86
11.4. 424 Failed Dependency . . . . . . . . . . . . . . . . . 86
11.5. 507 Insufficient Storage . . . . . . . . . . . . . . . . 86
12. Use of HTTP Status Codes . . . . . . . . . . . . . . . . . . 87
12.1. 412 Precondition Failed . . . . . . . . . . . . . . . . 87
12.2. 414 Request-URI Too Long . . . . . . . . . . . . . . . . 87
13. Multi-Status Response . . . . . . . . . . . . . . . . . . . . 88
13.1. Response Headers . . . . . . . . . . . . . . . . . . . . 88
13.2. Handling Redirected Child Resources . . . . . . . . . . 89
13.3. Internal Status Codes . . . . . . . . . . . . . . . . . 89
14. XML Element Definitions . . . . . . . . . . . . . . . . . . . 90
14.1. activelock XML Element . . . . . . . . . . . . . . . . . 90
14.2. allprop XML Element . . . . . . . . . . . . . . . . . . 90
14.3. collection XML Element . . . . . . . . . . . . . . . . . 90
14.4. depth XML Element . . . . . . . . . . . . . . . . . . . 90
14.5. error XML Element . . . . . . . . . . . . . . . . . . . 91
14.6. exclusive XML Element . . . . . . . . . . . . . . . . . 91
14.7. href XML Element . . . . . . . . . . . . . . . . . . . . 91
14.8. include XML Element . . . . . . . . . . . . . . . . . . 92
14.9. location XML Element . . . . . . . . . . . . . . . . . . 92
14.10. lockentry XML Element . . . . . . . . . . . . . . . . . 92
14.11. lockinfo XML Element . . . . . . . . . . . . . . . . . . 93
14.12. lockroot XML Element . . . . . . . . . . . . . . . . . . 93
14.13. lockscope XML Element . . . . . . . . . . . . . . . . . 93
14.14. locktoken XML Element . . . . . . . . . . . . . . . . . 93
14.15. locktype XML Element . . . . . . . . . . . . . . . . . . 94
14.16. multistatus XML Element . . . . . . . . . . . . . . . . 94
14.17. owner XML Element . . . . . . . . . . . . . . . . . . . 94
14.18. prop XML Element . . . . . . . . . . . . . . . . . . . . 95
14.19. propertyupdate XML Element . . . . . . . . . . . . . . . 95
14.20. propfind XML Element . . . . . . . . . . . . . . . . . . 95
14.21. propname XML Element . . . . . . . . . . . . . . . . . . 95
14.22. propstat XML Element . . . . . . . . . . . . . . . . . . 96
14.23. remove XML Element . . . . . . . . . . . . . . . . . . . 96
14.24. response XML Element . . . . . . . . . . . . . . . . . . 96
14.25. responsedescription XML Element . . . . . . . . . . . . 97
14.26. set XML Element . . . . . . . . . . . . . . . . . . . . 97
14.27. shared XML Element . . . . . . . . . . . . . . . . . . . 97
14.28. status XML Element . . . . . . . . . . . . . . . . . . . 98
14.29. timeout XML Element . . . . . . . . . . . . . . . . . . 98
14.30. write XML Element . . . . . . . . . . . . . . . . . . . 98
15. DAV Properties . . . . . . . . . . . . . . . . . . . . . . . 99
15.1. creationdate Property . . . . . . . . . . . . . . . . . 99
15.2. displayname Property . . . . . . . . . . . . . . . . . . 100
15.3. getcontentlanguage Property . . . . . . . . . . . . . . 100
15.4. getcontentlength Property . . . . . . . . . . . . . . . 101
15.5. getcontenttype Property . . . . . . . . . . . . . . . . 101
15.6. getetag Property . . . . . . . . . . . . . . . . . . . . 102
15.7. getlastmodified Property . . . . . . . . . . . . . . . . 102
15.8. lockdiscovery Property . . . . . . . . . . . . . . . . . 103
15.8.1. Example - Retrieving DAV:lockdiscovery . . . . . . . 104
15.9. resourcetype Property . . . . . . . . . . . . . . . . . 105
15.10. supportedlock Property . . . . . . . . . . . . . . . . . 106
15.10.1. Example - Retrieving DAV:supportedlock . . . . . . . 107
16. Precondition/Postcondition XML Elements . . . . . . . . . . . 108
17. XML Extensibility in DAV . . . . . . . . . . . . . . . . . . 112
18. DAV Compliance Classes . . . . . . . . . . . . . . . . . . . 114
18.1. Class 1 . . . . . . . . . . . . . . . . . . . . . . . . 114
18.2. Class 2 . . . . . . . . . . . . . . . . . . . . . . . . 114
18.3. Class 3 . . . . . . . . . . . . . . . . . . . . . . . . 114
19. Internationalization Considerations . . . . . . . . . . . . . 116
20. Security Considerations . . . . . . . . . . . . . . . . . . . 118
20.1. Authentication of Clients . . . . . . . . . . . . . . . 118
20.2. Denial of Service . . . . . . . . . . . . . . . . . . . 118
20.3. Security through Obscurity . . . . . . . . . . . . . . . 119
20.4. Privacy Issues Connected to Locks . . . . . . . . . . . 119
20.5. Privacy Issues Connected to Properties . . . . . . . . . 119
20.6. Implications of XML Entities . . . . . . . . . . . . . . 120
20.7. Risks Connected with Lock Tokens . . . . . . . . . . . . 120
20.8. Hosting Malicious Content . . . . . . . . . . . . . . . 121
21. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 122
21.1. New URI Schemes . . . . . . . . . . . . . . . . . . . . 122
21.2. XML Namespaces . . . . . . . . . . . . . . . . . . . . . 122
21.3. Message Header Fields . . . . . . . . . . . . . . . . . 122
21.3.1. DAV . . . . . . . . . . . . . . . . . . . . . . . . 122
21.3.2. Depth . . . . . . . . . . . . . . . . . . . . . . . 122
21.3.3. Destination . . . . . . . . . . . . . . . . . . . . 123
21.3.4. If . . . . . . . . . . . . . . . . . . . . . . . . . 123
21.3.5. Lock-Token . . . . . . . . . . . . . . . . . . . . . 123
21.3.6. Overwrite . . . . . . . . . . . . . . . . . . . . . 123
21.3.7. Timeout . . . . . . . . . . . . . . . . . . . . . . 124
22. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 125
23. Contributors to This Specification . . . . . . . . . . . . . 127
24. Authors of RFC2518 . . . . . . . . . . . . . . . . . . . . . 128
25. References . . . . . . . . . . . . . . . . . . . . . . . . . 129
25.1. Normative References . . . . . . . . . . . . . . . . . . 129
25.2. Informational References . . . . . . . . . . . . . . . . 130
Appendix A. Notes on Processing XML Elements . . . . . . . . . . 131
A.1. Notes on Empty XML Elements . . . . . . . . . . . . . . 131
A.2. Notes on Illegal XML Processing . . . . . . . . . . . . 131
A.3. Example - XML Syntax Error . . . . . . . . . . . . . . . 131
A.4. Example - Unexpected XML Element . . . . . . . . . . . . 132
Appendix B. Notes on HTTP Client Compatibility . . . . . . . . . 134
Appendix C. The 'opaquelocktoken' Scheme and URIs . . . . . . . 135
Appendix D. Lock-null Resources . . . . . . . . . . . . . . . . 136
D.1. Guidance for Clients Using LOCK to Create Resources . . 136
Appendix E. Guidance for Clients Desiring to Authenticate . . . 138
Appendix F. Summary of changes from RFC2518 . . . . . . . . . . 140
F.1. Changes for both Client and Server Implementations . . . 140
F.2. Changes for Server Implementations . . . . . . . . . . . 141
F.3. Other Changes . . . . . . . . . . . . . . . . . . . . . 142
Appendix G. Change Log (to be removed by RFC Editor before
publication) . . . . . . . . . . . . . . . . . . . . 144
G.1. Changes from -05 to -06 . . . . . . . . . . . . . . . . 144
G.2. Changes in -07 . . . . . . . . . . . . . . . . . . . . . 144
G.3. Changes in -08 . . . . . . . . . . . . . . . . . . . . . 145
G.4. Changes in -09 . . . . . . . . . . . . . . . . . . . . . 146
G.5. Changes in -10 . . . . . . . . . . . . . . . . . . . . . 147
G.6. Changes in -11 . . . . . . . . . . . . . . . . . . . . . 147
G.7. Changes in -12 . . . . . . . . . . . . . . . . . . . . . 147
G.8. Changes in -13 . . . . . . . . . . . . . . . . . . . . . 148
G.9. Changes in -14 . . . . . . . . . . . . . . . . . . . . . 148
G.10. Changes in -15 . . . . . . . . . . . . . . . . . . . . . 148
G.11. Changes in -16 . . . . . . . . . . . . . . . . . . . . . 148
G.12. Changes in -17 . . . . . . . . . . . . . . . . . . . . . 149
G.13. Changes in -18 . . . . . . . . . . . . . . . . . . . . . 149
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 150
Intellectual Property and Copyright Statements . . . . . . . . . 151
1. Introduction 1. Introduction
This document describes an extension to the HTTP/1.1 protocol that This document describes an extension to the HTTP/1.1 protocol that
allows clients to perform remote web content authoring operations. allows clients to perform remote web content authoring operations.
This extension provides a coherent set of methods, headers, request This extension provides a coherent set of methods, headers, request
entity body formats, and response entity body formats that provide entity body formats, and response entity body formats that provide
operations for: operations for:
Properties: The ability to create, remove, and query information Properties: The ability to create, remove, and query information
about Web pages, such as their authors, creation dates, etc. Also, about Web pages, such as their authors, creation dates, etc.
the ability to link pages of any media type to related pages.
Collections: The ability to create sets of documents and to retrieve Collections: The ability to create sets of documents and to retrieve
a hierarchical membership listing (like a directory listing in a file a hierarchical membership listing (like a directory listing in a file
system). system).
Locking: The ability to keep more than one person from working on a Locking: The ability to keep more than one person from working on a
document at the same time. This prevents the "lost update problem," document at the same time. This prevents the "lost update problem",
in which modifications are lost as first one author then another in which modifications are lost as first one author then another
writes changes without merging the other author's changes. writes changes without merging the other author's changes.
Namespace Operations: The ability to instruct the server to copy and Namespace Operations: The ability to instruct the server to copy and
move Web resources. move Web resources, operations which change the mapping from URLs to
resources.
Requirements and rationale for these operations are described in a Requirements and rationale for these operations are described in a
companion document, "Requirements for a Distributed Authoring and companion document, "Requirements for a Distributed Authoring and
Versioning Protocol for the World Wide Web" [RFC2291]. Versioning Protocol for the World Wide Web" [RFC2291].
The sections below provide a detailed introduction to resource This document does not specify the versioning operations suggested by
properties (Section 4), collections of resources (Section 5), and [RFC2291]. That work was done in a separate document, "Versioning
locking operations (Section 6). These sections introduce the Extensions to WebDAV" [RFC3253].
abstractions manipulated by the WebDAV-specific HTTP methods
described in Section 8, "HTTP Methods for Distributed Authoring".
In HTTP/1.1, method parameter information was exclusively encoded in
HTTP headers. Unlike HTTP/1.1, WebDAV encodes method parameter
information either in an Extensible Markup Language (XML) [REC-XML]
request entity body, or in an HTTP header. The use of XML to encode
method parameters was motivated by the ability to add extra XML
elements to existing structures, providing extensibility; and by
XML's ability to encode information in ISO 10646 character sets,
providing internationalization support. As a rule of thumb,
parameters are encoded in XML entity bodies when they have unbounded
length, or when they may be shown to a human user and hence require
encoding in an ISO 10646 character set. Otherwise, parameters are
encoded within HTTP headers. Section 9 describes the new HTTP
headers used with WebDAV methods.
In addition to encoding method parameters, XML is used in WebDAV to
encode the responses from methods, providing the extensibility and
internationalization advantages of XML for method output, as well as
input.
XML elements used in this specification are defined in Section 12. The sections below provide a detailed introduction to various WebDAV
abstractions: resource properties (Section 4), collections of
resources (Section 5), locks (Section 6) in general and write locks
(Section 7) specifically.
The XML namespace extension (Appendix A.4) is also used in this These abstractions are manipulated by the WebDAV-specific HTTP
specification in order to allow for new XML elements to be added methods (Section 9) and the extra HTTP headers (Section 10) used with
without fear of colliding with other element names. WebDAV methods. General considerations for handling HTTP requests
and responses in WebDAV are found in Section 8.
While the status codes provided by HTTP/1.1 are sufficient to While the status codes provided by HTTP/1.1 are sufficient to
describe most error conditions encountered by WebDAV methods, there describe most error conditions encountered by WebDAV methods, there
are some errors that do not fall neatly into the existing categories. are some errors that do not fall neatly into the existing categories.
New status codes developed for the WebDAV methods are defined in This specification defines extra status codes developed for WebDAV
Section 10. Since some WebDAV methods may operate over many methods (Section 11) and describes existing HTTP status codes
resources, the Multi-Status response has been introduced to return (Section 12) as used in WebDAV. Since some WebDAV methods may
status information for multiple resources. The Multi-Status response operate over many resources, the Multi-Status response (Section 13)
is described in Section 11. has been introduced to return status information for multiple
resources. Finally, this version of WebDAV introduces precondition
and postcondition (Section 16) XML elements in error response bodies.
WebDAV employs the property mechanism to store information about the WebDAV uses XML ([REC-XML]) for property names and some values, and
current state of the resource. For example, when a lock is taken out also uses XML to marshal complicated requests and responses. This
on a resource, a lock information property describes the current specification contains DTD and text definitions of all all properties
state of the lock. Section 13 defines the properties used within the (Section 15) and all other XML elements (Section 14) used in
WebDAV specification. marshalling. WebDAV includes a few special rules on extending
WebDAV XML marshalling in backwards-compatible ways (Section 17).
Finishing off the specification are sections on what it means to be Finishing off the specification are sections on what it means for a
compliant with this specification (Section 15), on resource to be compliant with this specification (Section 18), on
internationalization support (Section 16), and on security internationalization support (Section 19), and on security
(Section 17). (Section 20).
2. Notational Conventions 2. Notational Conventions
Since this document describes a set of extensions to the HTTP/1.1 Since this document describes a set of extensions to the HTTP/1.1
protocol, the augmented BNF used herein to describe protocol elements protocol, the augmented BNF used herein to describe protocol elements
is exactly the same as described in section 2.1 of [RFC2068]. Since is exactly the same as described in Section 2.1 of [RFC2616],
this augmented BNF uses the basic production rules provided in including the rules about implied linear white-space. Since this
section 2.2 of [RFC2068], these rules apply to this document as well. augmented BNF uses the basic production rules provided in Section 2.2
of [RFC2616], these rules apply to this document as well.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in [RFC2119].
Note that in natural language, a property like the "creationdate"
property in the "DAV:" XML namespace is sometimes referred to as
"DAV:creationdate" for brevity.
3. Terminology 3. Terminology
URI/URL - A Uniform Resource Identifier and Uniform Resource Locator, URI/URL - A Uniform Resource Identifier and Uniform Resource Locator,
respectively. These terms (and the distinction between them) are respectively. These terms (and the distinction between them) are
defined in [RFC2396]. defined in [RFC3986].
Collection - A resource that contains a set of URIs, termed member URI/URL Mapping - A relation between an absolute URI and a resource.
URIs, which identify member resources and meets the requirements in Since a resource can represent items that are not network
Section 5 of this specification. retrievable, as well as those that are, it is possible for a resource
to have zero, one, or many URI mappings. Mapping a resource to an
"http" scheme URI makes it possible to submit HTTP protocol requests
to the resource using the URI.
Member URI - A URI which is a member of the set of URIs contained by Path Segment - Informally, the characters found between slashes ("/")
a collection. in a URI. Formally, as defined in Section 3.3 of [RFC3986].
Internal Member URI - A Member URI that is immediately relative to Collection - Informally, a resource that also acts as a container of
the URI of the collection (the definition of immediately relative is references to child resources. Formally, a resource that contains a
given in Section 5.2). set of mappings between path segments and resources and meets the
requirements defined in Section 5.
Internal Member (of a Collection) - Informally, a child resource of a
collection. Formally, a resource referenced by a path segment
mapping contained in the collection.
Internal Member URL (of a Collection) - A URL of an internal member,
consisting of the URL of the collection (including trailing slash)
plus the path segment identifying the internal member.
Member (of a Collection) - Informally, a "descendant" of a
collection. Formally, an internal member of the collection, or,
recursively, a member of an internal member.
Member URL (of a Collection) - A URL that is either an internal
member URL of the collection itself, or is an internal member URL of
a member of that collection.
Property - A name/value pair that contains descriptive information Property - A name/value pair that contains descriptive information
about a resource. about a resource.
Live Property - A property whose semantics and syntax are enforced by Live Property - A property whose semantics and syntax are enforced by
the server. For example, the live "getcontentlength" property has the server. For example, the live property DAV:getcontentlength has
its value, the length of the entity returned by a GET request, its value, the length of the entity returned by a GET request,
automatically calculated by the server. automatically calculated by the server.
Dead Property - A property whose semantics and syntax are not Dead Property - A property whose semantics and syntax are not
enforced by the server. The server only records the value of a dead enforced by the server. The server only records the value of a dead
property; the client is responsible for maintaining the consistency property; the client is responsible for maintaining the consistency
of the syntax and semantics of a dead property. of the syntax and semantics of a dead property.
Null Resource - A resource which responds with a 404 (Not Found) to Principal - A "principal" is a distinct human or computational actor
any HTTP/1.1 or DAV method except for PUT, MKCOL, OPTIONS and LOCK. that initiates access to network resources.
A NULL resource MUST NOT appear as a member of its parent collection.
State Token - A URI which represents a state of a resource. Lock
tokens are the only state tokens defined in this specification.
4. Data Model for Resource Properties 4. Data Model for Resource Properties
4.1. The Resource Property Model 4.1. The Resource Property Model
Properties are pieces of data that describe the state of a resource. Properties are pieces of data that describe the state of a resource.
Properties are data about data. Properties are data about data.
Properties are used in distributed authoring environments to provide Properties are used in distributed authoring environments to provide
for efficient discovery and management of resources. For example, a for efficient discovery and management of resources. For example, a
'subject' property might allow for the indexing of all resources by 'subject' property might allow for the indexing of all resources by
their subject, and an 'author' property might allow for the discovery their subject, and an 'author' property might allow for the discovery
of what authors have written which documents. of what authors have written which documents.
The DAV property model consists of name/value pairs. The name of a The DAV property model consists of name/value pairs. The name of a
property identifies the property's syntax and semantics, and provides property identifies the property's syntax and semantics, and provides
an address by which to refer to its syntax and semantics. an address by which to refer to its syntax and semantics.
There are two categories of properties: "live" and "dead". A live There are two categories of properties: "live" and "dead". A live
property has its syntax and semantics enforced by the server. Live property has its syntax and semantics enforced by the server. Live
properties include cases where a) the value of a property is read- properties include cases where a) the value of a property is
only, maintained by the server, and b) the value of the property is protected, maintained by the server, and b) the value of the property
maintained by the client, but the server performs syntax checking on is maintained by the client, but the server performs syntax checking
submitted values. All instances of a given live property MUST comply on submitted values. All instances of a given live property MUST
with the definition associated with that property name. A dead comply with the definition associated with that property name. A
property has its syntax and semantics enforced by the client; the dead property has its syntax and semantics enforced by the client;
server merely records the value of the property verbatim. the server merely records the value of the property verbatim.
4.2. Existing Metadata Proposals
Properties have long played an essential role in the maintenance of
large document repositories, and many current proposals contain some
notion of a property, or discuss web metadata more generally. These
include PICS [REC-PICS], PICS-NG, XML, Web Collections, and several
proposals on representing relationships within HTML. Work on PICS-NG
and Web Collections has been subsumed by the Resource Description
Framework (RDF) metadata activity of the World Wide Web Consortium.
RDF consists of a network-based data model and an XML representation
of that model.
Some proposals come from a digital library perspective. These
include the Dublin Core [RFC2413] metadata set and the Warwick
Framework [WF], a container architecture for different metadata
schemas. The literature includes many examples of metadata,
including MARC [USMARC], a bibliographic metadata format, and a
technical report bibliographic format employed by the Dienst system
[RFC1807]. Additionally, the proceedings from the first IEEE
Metadata conference describe many community-specific metadata sets.
Participants of the 1996 Metadata II Workshop in Warwick, UK [WF],
noted that "new metadata sets will develop as the networked
infrastructure matures" and "different communities will propose,
design, and be responsible for different types of metadata." These
observations can be corroborated by noting that many community-
specific sets of metadata already exist, and there is significant
motivation for the development of new forms of metadata as many
communities increasingly make their data available in digital form,
requiring a metadata format to assist data location and cataloging.
4.3. Properties and HTTP Headers 4.2. Properties and HTTP Headers
Properties already exist, in a limited sense, in HTTP message Properties already exist, in a limited sense, in HTTP message
headers. However, in distributed authoring environments a relatively headers. However, in distributed authoring environments a relatively
large number of properties are needed to describe the state of a large number of properties are needed to describe the state of a
resource, and setting/returning them all through HTTP headers is resource, and setting/returning them all through HTTP headers is
inefficient. Thus a mechanism is needed which allows a principal to inefficient. Thus a mechanism is needed which allows a principal to
identify a set of properties in which the principal is interested and identify a set of properties in which the principal is interested and
to set or retrieve just those properties. to set or retrieve just those properties.
4.4. Property Values 4.3. Property Values
The value of a property when expressed in XML MUST be well formed. The value of a property is always a (well-formed) XML fragment.
XML has been chosen because it is a flexible, self-describing, XML has been chosen because it is a flexible, self-describing,
structured data format that supports rich schema definitions, and structured data format that supports rich schema definitions, and
because of its support for multiple character sets. XML's self- because of its support for multiple character sets. XML's self-
describing nature allows any property's value to be extended by describing nature allows any property's value to be extended by
adding new elements. Older clients will not break when they adding elements. Clients will not break when they encounter
encounter extensions because they will still have the data specified extensions because they will still have the data specified in the
in the original schema and will ignore elements they do not original schema and MUST ignore elements they do not understand.
understand. XML's support for multiple character sets allows any
human-readable property to be encoded and read in a character set
familiar to the user. XML's support for multiple human languages,
using the "xml:lang" attribute, handles cases where the same
character set is employed by multiple human languages.
4.5. Property Names XML's support for multiple character sets allows any human-readable
property to be encoded and read in a character set familiar to the
user. XML's support for multiple human languages, using the "xml:
lang" attribute, handles cases where the same character set is
employed by multiple human languages. Note that xml:lang scope is
recursive, so an xml:lang attribute on any element containing a
property name element applies to the property value unless it has
been overridden by a more locally scoped attribute. Note that a
property only has one value, in one language (or language MAY be left
undefined), not multiple values in different languages or a single
value in multiple languages.
A property is always represented with an XML element consisting of
the property name, called the "property name element". The simplest
example is an empty property, which is different from a property that
does not exist:
<R:title xmlns:R="http://www.example.com/ns/"></R:title>
The value of the property appears inside the property name element.
The value may be any kind of well-formed XML content, including both
text-only and mixed content. Servers MUST preserve the following XML
Information Items (using the terminology from [REC-XML-INFOSET]) in
storage and transmission of dead properties:
For the property name Element Information Item itself:
[namespace name]
[local name]
[attributes] named "xml:lang" or any such attribute in scope
[children] of type element or character
On all Element Information Items in the property value:
[namespace name]
[local name]
[attributes]
[children] of type element or character
On Attribute Information Items in the property value:
[namespace name]
[local name]
[normalized value]
On Character Information Items in the property value:
[character code]
Since prefixes are used in some XML vocabularies (XPath and XML
Schema, for example), servers SHOULD preserve, for any Information
Item in the value:
[prefix]
XML Infoset attributes not listed above MAY be preserved by the
server, but clients MUST NOT rely on them being preserved. The above
rules would also apply by default to live properties, unless defined
otherwise.
Servers MUST ignore the XML attribute xml:space if present and never
use it to change white space handling. White space in property
values is significant.
4.3.1. Example - Property with Mixed Content
Consider a dead property 'author' created by the client as follows:
<D:prop xml:lang="en" xmlns:D="DAV:">
<x:author xmlns:x='http://example.com/ns'>
<x:name>Jane Doe</x:name>
<!-- Jane's contact info -->
<x:uri type='email'
added='2005-11-26'>mailto:jane.doe@example.com</x:uri>
<x:uri type='web'
added='2005-11-27'>http://www.example.com</x:uri>
<x:notes xmlns:h='http://www.w3.org/1999/xhtml'>
Jane has been working way <h:em>too</h:em> long on the
long-awaited revision of <![CDATA[<RFC2518>]]>.
</x:notes>
</x:author>
</D:prop>
When this property is requested, a server might return:
<D:prop xmlns:D='DAV:'><author
xml:lang='en'
xmlns:x='http://example.com/ns'
xmlns='http://example.com/ns'
xmlns:h='http://www.w3.org/1999/xhtml'>
<x:name>Jane Doe</x:name>
<x:uri added="2005-11-26" type="email"
>mailto:jane.doe@example.com</x:uri>
<x:uri added="2005-11-27" type="web"
>http://www.example.com</x:uri>
<x:notes>
Jane has been working way <h:em>too</h:em> long on the
long-awaited revision of &lt;RFC2518&gt;.
</x:notes>
</author>
</D:prop>
Note in this example:
o The [prefix] for the property name itself was not preserved, being
non-significant, all other [prefix] values have been preserved,
o attribute values have been rewritten with double quotes instead of
single quotes (quoting style is not significant), and attribute
order has not been preserved,
o the xml:lang attribute has been returned on the property name
element itself (it was in scope when the property was set, but the
exact position in the response is not considered significant as
long as it is in scope),
o whitespace between tags has been preserved everywhere (whitespace
between attributes not so),
o CDATA encapsulation was replaced with character escaping (the
reverse would also be legal),
o the comment item was stripped (as would have been a processing
instruction item).
Implementation note: there are cases such as editing scenarios where
clients may require that XML content is preserved character-by-
character (such as attribute ordering or quoting style). In this
case, clients should consider using a text-only property value by
escaping all characters that have a special meaning in XML parsing.
4.4. Property Names
A property name is a universally unique identifier that is associated A property name is a universally unique identifier that is associated
with a schema that provides information about the syntax and with a schema that provides information about the syntax and
semantics of the property. semantics of the property.
Because a property's name is universally unique, clients can depend Because a property's name is universally unique, clients can depend
upon consistent behavior for a particular property across multiple upon consistent behavior for a particular property across multiple
resources, on the same and across different servers, so long as that resources, on the same and across different servers, so long as that
property is "live" on the resources in question, and the property is "live" on the resources in question, and the
implementation of the live property is faithful to its definition. implementation of the live property is faithful to its definition.
The XML namespace mechanism, which is based on URIs [RFC2396], is The XML namespace mechanism, which is based on URIs ([RFC3986]), is
used to name properties because it prevents namespace collisions and used to name properties because it prevents namespace collisions and
provides for varying degrees of administrative control. provides for varying degrees of administrative control.
The property namespace is flat; that is, no hierarchy of properties The property namespace is flat; that is, no hierarchy of properties
is explicitly recognized. Thus, if a property A and a property A/B is explicitly recognized. Thus, if a property A and a property A/B
exist on a resource, there is no recognition of any relationship exist on a resource, there is no recognition of any relationship
between the two properties. It is expected that a separate between the two properties. It is expected that a separate
specification will eventually be produced which will address issues specification will eventually be produced which will address issues
relating to hierarchical properties. relating to hierarchical properties.
Finally, it is not possible to define the same property twice on a Finally, it is not possible to define the same property twice on a
single resource, as this would cause a collision in the resource's single resource, as this would cause a collision in the resource's
property namespace. property namespace.
4.6. Media Independent Links 4.5. Source Resources and Output Resources
Although HTML resources support links to other resources, the Web Some HTTP resources are dynamically generated by the server. For
needs more general support for links between resources of any media these resources, there presumably exists source code somewhere
type (media types are also known as MIME types, or content types). governing how that resource is generated. The relationship of source
WebDAV provides such links. A WebDAV link is a special type of files to output HTTP resources may be one to one, one to many, many
property value, formally defined in Section 12.4, that allows typed to one or many to many. There is no mechanism in HTTP to determine
connections to be established between resources of any media type. whether a resource is even dynamic, let alone where its source files
The property value consists of source and destination Uniform exist or how to author them. Although this problem would usefully be
Resource Identifiers (URIs); the property name identifies the link solved, interoperable WebDAV implementations have been widely
type. deployed without actually solving this problem, by dealing only with
static resources. Thus, the source vs. output problem is not solved
in this specification and has been deferred to a separate document.
5. Collections of Web Resources 5. Collections of Web Resources
This section provides a description of a new type of Web resource, This section provides a description of a type of Web resource, the
the collection, and discusses its interactions with the HTTP URL collection, and discusses its interactions with the HTTP URL
namespace. The purpose of a collection resource is to model namespace and with HTTP methods. The purpose of a collection
collection-like objects (e.g., file system directories) within a resource is to model collection-like objects (e.g., file system
server's namespace. directories) within a server's namespace.
All DAV compliant resources MUST support the HTTP URL namespace model All DAV compliant resources MUST support the HTTP URL namespace model
specified herein. specified herein.
5.1. HTTP URL Namespace Model 5.1. HTTP URL Namespace Model
The HTTP URL namespace is a hierarchical namespace where the The HTTP URL namespace is a hierarchical namespace where the
hierarchy is delimited with the "/" character. hierarchy is delimited with the "/" character.
An HTTP URL namespace is said to be consistent if it meets the An HTTP URL namespace is said to be consistent if it meets the
following conditions: for every URL in the HTTP hierarchy there following conditions: for every URL in the HTTP hierarchy there
exists a collection that contains that URL as an internal member. exists a collection that contains that URL as an internal member URL.
The root, or top-level collection of the namespace under The root, or top-level collection of the namespace under
consideration is exempt from the previous rule. consideration, is exempt from the previous rule. The top-level
collection of the namespace under consideration is not necessarily
the collection identified by the absolute path '/', it may be
identified by one or more path segments (e.g. /servlets/webdav/...)
Neither HTTP/1.1 nor WebDAV require that the entire HTTP URL Neither HTTP/1.1 nor WebDAV require that the entire HTTP URL
namespace be consistent. However, certain WebDAV methods are namespace be consistent -- a WebDAV-compatible resource may not have
prohibited from producing results that cause namespace a parent collection. However, certain WebDAV methods are prohibited
inconsistencies. from producing results that cause namespace inconsistencies.
Although implicit in [RFC2068] and [RFC2396], any resource, including As is implicit in [RFC2616] and [RFC3986], any resource, including
collection resources, MAY be identified by more than one URI. For collection resources, MAY be identified by more than one URI. For
example, a resource could be identified by multiple HTTP URLs. example, a resource could be identified by multiple HTTP URLs.
5.2. Collection Resources 5.2. Collection Resources
A collection is a resource whose state consists of at least a list of Collection resources differ from other resources in that they also
internal member URIs and a set of properties, but which may have act as containers. Some HTTP methods apply only to a collection, but
additional state such as entity bodies returned by GET. An internal some apply to some or all of the resources inside the container
member URI MUST be immediately relative to a base URI of the defined by the collection. When the scope of a method is not clear,
collection. That is, the internal member URI is equal to a the client can specify what depth to apply. Depth can be either zero
containing collection's URI plus an additional segment for non- levels in (only the collection), one level (the collection and
collection resources, or additional segment plus trailing slash "/" directly contained resources) or infinite levels (the collection and
for collection resources, where segment is defined in section 3.3 of all contained resources recursively).
[RFC2396].
Any given internal member URI MUST only belong to the collection
once, i.e., it is illegal to have multiple instances of the same URI
in a collection. Properties defined on collections behave exactly as
do properties on non-collection resources.
For all WebDAV compliant resources A and B, identified by URIs U and
V, for which U is immediately relative to V, B MUST be a collection
that has U as an internal member URI. So, if the resource with URL
http://foo.com/bar/blah is WebDAV compliant and if the resource with
URL http://foo.com/bar/ is WebDAV compliant then the resource with
URL http://foo.com/bar/ must be a collection and must contain URL
http://foo.com/bar/blah as an internal member.
Collection resources MAY list the URLs of non-WebDAV compliant
children in the HTTP URL namespace hierarchy as internal members but
are not required to do so. For example, if the resource with URL
http://foo.com/bar/blah is not WebDAV compliant and the URL
http://foo.com/bar/ identifies a collection then URL
http://foo.com/bar/blah may or may not be an internal member of the
collection with URL http://foo.com/bar/.
If a WebDAV compliant resource has no WebDAV compliant children in
the HTTP URL namespace hierarchy then the WebDAV compliant resource
is not required to be a collection.
There is a standing convention that when a collection is referred to
by its name without a trailing slash, the trailing slash is
automatically appended. Due to this, a resource may accept a URI
without a trailing "/" to point to a collection. In this case it
SHOULD return a content-location header in the response pointing to
the URI ending with the "/". For example, if a client invokes a
method on http://foo.bar/blah (no trailing slash), the resource
http://foo.bar/blah/ (trailing slash) may respond as if the operation
were invoked on it, and should return a content-location header with
http://foo.bar/blah/ in it. In general clients SHOULD use the "/"
form of collection names.
A resource MAY be a collection but not be WebDAV compliant. That is,
the resource may comply with all the rules set out in this
specification regarding how a collection is to behave without
necessarily supporting all methods that a WebDAV compliant resource
is required to support. In such a case the resource may return the
DAV:resourcetype property with the value DAV:collection but MUST NOT
return a DAV header containing the value "1" on an OPTIONS response.
5.3. Creation and Retrieval of Collection Resources
This document specifies the MKCOL method to create new collection A collection's state consists of at least a set of mappings between
resources, rather than using the existing HTTP/1.1 PUT or POST path segments and resources, and a set of properties on the
method, for the following reasons: collection itself. In this document, a resource B will be said to be
contained in the collection resource A if there is a path segment
mapping which maps to B and which is contained in A. A collection
MUST contain at most one mapping for a given path segment, i.e., it
is illegal to have the same path segment mapped to more than one
resource.
In HTTP/1.1, the PUT method is defined to store the request body at Properties defined on collections behave exactly as do properties on
the location specified by the Request-URI. While a description non-collection resources. A collection MAY have additional state
format for a collection can readily be constructed for use with PUT, such as entity bodies returned by GET.
the implications of sending such a description to the server are
undesirable. For example, if a description of a collection that
omitted some existing resources were PUT to a server, this might be
interpreted as a command to remove those members. This would extend
PUT to perform DELETE functionality, which is undesirable since it
changes the semantics of PUT, and makes it difficult to control
DELETE functionality with an access control scheme based on methods.
While the POST method is sufficiently open-ended that a "create a For all WebDAV compliant resources A and B, identified by URLs "U"
collection" POST command could be constructed, this is undesirable and "V" respectively, such that "V" is equal to "U/SEGMENT", A MUST
because it would be difficult to separate access control for be a collection that contains a mapping from "SEGMENT" to B. So, if
collection creation from other uses of POST. resource B with URL "http://example.com/bar/blah" is WebDAV compliant
and if resource A with URL "http://example.com/bar/" is WebDAV
compliant, then resource A must be a collection and must contain
exactly one mapping from "blah" to B.
The exact definition of the behavior of GET and PUT on collections is Although commonly a mapping consists of a single segment and a
defined later in this document. resource, in general, a mapping consists of a set of segments and a
resource. This allows a server to treat a set of segments as
equivalent (i.e. either all of the segments are mapped to the same
resource, or none of the segments are mapped to a resource). For
example, a server that performs case-folding on segments will treat
the segments "ab", "Ab", "aB", and "AB" as equivalent. A client can
then use any of these segments to identify the resource. Note that a
PROPFIND result will select one of these equivalent segments to
identify the mapping, so there will be one PROPFIND response element
per mapping, not one per segment in the mapping.
5.4. Source Resources and Output Resources Collection resources MAY have mappings to non-WebDAV compliant
resources in the HTTP URL namespace hierarchy but are not required to
do so. For example, if resource X with URL
"http://example.com/bar/blah" is not WebDAV compliant and resource A
with "URL http://example.com/bar/" identifies a WebDAV collection,
then A may or may not have a mapping from "blah" to X.
For many resources, the entity returned by a GET method exactly If a WebDAV compliant resource has no WebDAV compliant internal
matches the persistent state of the resource, for example, a GIF file members in the HTTP URL namespace hierarchy then the WebDAV compliant
stored on a disk. For this simple case, the URI at which a resource resource is not required to be a collection.
is accessed is identical to the URI at which the source (the
persistent state) of the resource is accessed. This is also the case
for HTML source files that are not processed by the server prior to
transmission.
However, the server can sometimes process HTML resources before they There is a standing convention that when a collection is referred to
are transmitted as a return entity body. For example, a server-side- by its name without a trailing slash, the server MAY handle the
include directive within an HTML file might instruct a server to request as if the trailing slash were present. In this case it
replace the directive with another value, such as the current date. SHOULD return a Content-Location header in the response, pointing to
In this case, what is returned by GET (HTML plus date) differs from the URL ending with the "/". For example, if a client invokes a
the persistent state of the resource (HTML plus directive). method on http://example.com/blah (no trailing slash), the server may
Typically there is no way to access the HTML resource containing the respond as if the operation were invoked on http://example.com/blah/
unprocessed directive. (trailing slash), and should return a Content-Location header with
the value http://example.com/blah/. Wherever a server produces a URL
referring to a collection, the server SHOULD include the trailing
slash. In general clients SHOULD use the trailing slash form of
collection names. If clients do not use the trailing slash form the
client needs to be prepared to see a redirect response. Clients will
find the DAV:resourcetype property more reliable than the URL to find
out if a resource is a collection.
Sometimes the entity returned by GET is the output of a data- Clients MUST be able to support the case where WebDAV resources are
producing process that is described by one or more source resources contained inside non-WebDAV resources. For example, if a OPTIONS
(that may not even have a location in the URI namespace). A single response from "http://example.com/servlet/dav/collection" indicates
data-producing process may dynamically generate the state of a WebDAV support, the client cannot assume that
potentially large number of output resources. An example of this is "http://example.com/servlet/dav/" or its parent necessarily are
a CGI script that describes a "finger" gateway process that maps part WebDAV collections.
of the namespace of a server into finger requests, such as
http://www.foo.bar.org/finger_gateway/user@host.
In the absence of distributed authoring capabilities, it is A typical scenario in which mapped URLs do not appear as members of
acceptable to have no mapping of source resource(s) to the URI their parent collection is the case where a server allows links or
namespace. In fact, preventing access to the source resource(s) has redirects to non-WebDAV resources. For instance, "/col/link" might
desirable security benefits. However, if remote editing of the not appear as a member of "/col/", although the server would respond
source resource(s) is desired, the source resource(s) should be given with a 302 status to a GET request to "/col/link", thus the URL
a location in the URI namespace. This source location should not be "/col/link" would indeed be mapped. Similarly, a dynamically-
one of the locations at which the generated output is retrievable, generated page might have a URL mapping from "/col/index.html", thus
since in general it is impossible for the server to differentiate this resource might respond with a 200 OK to a GET request yet not
requests for source resources from requests for process output appear as a member of "/col/".
resources. There is often a many-to-many relationship between source
resources and output resources.
On WebDAV compliant servers the URI of the source resource(s) may be Some mappings to even WebDAV-compliant resources might not appear in
stored in a link on the output resource with type DAV:source (see the parent collection. An example for this case are servers that
Section 13.10 for a description of the source link property). support multiple alias URLs for each WebDAV compliant resource. A
Storing the source URIs in links on the output resources places the server may implement case-insensitive URLs, thus "/col/a" and
burden of discovering the source on the authoring client. Note that "/col/A" identify the same resource, yet only either "a" or "A" are
the value of a source link is not guaranteed to point to the correct reported upon listing the members of "/col". In cases where a server
source. Source links may break or incorrect values may be entered. treats a set of segments as equivalent, the server MUST expose only
Also note that not all servers will allow the client to set the one preferred segment per mapping, consistently chosen, in PROPFIND
source link value. For example a server which generates source links responses.
on the fly for its CGI files will most likely not allow a client to
set the source link value.
6. Locking 6. Locking
The ability to lock a resource provides a mechanism for serializing The ability to lock a resource provides a mechanism for serializing
access to that resource. Using a lock, an authoring client can access to that resource. Using a lock, an authoring client can
provide a reasonable guarantee that another principal will not modify provide a reasonable guarantee that another principal will not modify
a resource while it is being edited. In this way, a client can a resource while it is being edited. In this way, a client can
prevent the "lost update" problem. prevent the "lost update" problem.
This specification allows locks to vary over two client-specified This specification allows locks to vary over two client-specified
parameters, the number of principals involved (exclusive vs. shared) parameters, the number of principals involved (exclusive vs. shared)
and the type of access to be granted. This document defines locking and the type of access to be granted. This document defines locking
for only one access type, write. However, the syntax is extensible, for only one access type, write. However, the syntax is extensible,
and permits the eventual specification of locking for other access and permits the eventual specification of locking for other access
types. types.
6.1. Exclusive Vs. Shared Locks 6.1. Lock Model
The most basic form of lock is an exclusive lock. This is a lock This section provides a concise model for how locking behaves. Later
where the access right in question is only granted to a single sections will provide more detail on some of the concepts and refer
principal. The need for this arbitration results from a desire to back to these model statements. Normative statements related to LOCK
avoid having to merge results. and UNLOCK method handling can be found in the sections on those
methods, whereas normative statements that cover any method are
gathered here.
1. A lock either directly or indirectly locks a resource.
2. A resource becomes directly locked when a LOCK request to a URL
of that resource creates a new lock. The "lock-root" of the new
lock is that URL. If at the time of the request, the URL is not
mapped to a resource, a new empty resource is created and
directly locked.
3. An exclusive lock (Section 6.2) conflicts with any other kind of
lock on the same resource, whether either lock is direct or
indirect. A server MUST NOT create conflicting locks on a
resource.
4. For a collection that is locked with a depth-infinity lock L, all
member resources are indirectly locked. Changes in membership of
a such a collection affect the set of indirectly locked
resources:
* If a member resource is added to the collection, the new
member resource MUST NOT already have a conflicting lock,
because the new resource MUST become indirectly locked by L.
* If a member resource stops being a member of the collection,
then the resource MUST no longer be indirectly locked by L.
5. Each lock is identified by a single globally unique lock token
(Section 6.5).
6. An UNLOCK request deletes the lock with the specified lock token.
After a lock is deleted, no resource is locked by that lock.
7. A lock token is "submitted" in a request when it appears in an
"If" header (the Write Lock (Section 7) section discusses when
token submission is required for write locks).
8. If a request causes the lock-root of any lock to become an
unmapped URL, then the lock MUST also be deleted by that request.
6.2. Exclusive Vs. Shared Locks
The most basic form of lock is an exclusive lock. Exclusive locks
avoid having to deal with content change conflicts, without requiring
any coordination other than the methods described in this
specification.
However, there are times when the goal of a lock is not to exclude However, there are times when the goal of a lock is not to exclude
others from exercising an access right but rather to provide a others from exercising an access right but rather to provide a
mechanism for principals to indicate that they intend to exercise mechanism for principals to indicate that they intend to exercise
their access rights. Shared locks are provided for this case. A their access rights. Shared locks are provided for this case. A
shared lock allows multiple principals to receive a lock. Hence any shared lock allows multiple principals to receive a lock. Hence any
principal with appropriate access can get the lock. principal that has both access privileges and a valid lock can use
the locked resource.
With shared locks there are two trust sets that affect a resource. With shared locks there are two trust sets that affect a resource.
The first trust set is created by access permissions. Principals who The first trust set is created by access permissions. Principals who
are trusted, for example, may have permission to write to the are trusted, for example, may have permission to write to the
resource. Among those who have access permission to write to the resource. Among those who have access permission to write to the
resource, the set of principals who have taken out a shared lock also resource, the set of principals who have taken out a shared lock also
must trust each other, creating a (typically) smaller trust set must trust each other, creating a (typically) smaller trust set
within the access permission write set. within the access permission write set.
Starting with every possible principal on the Internet, in most Starting with every possible principal on the Internet, in most
skipping to change at page 15, line 42 skipping to change at page 23, line 7
decide they trust their collaborators will not overwrite their work decide they trust their collaborators will not overwrite their work
(the potential set of collaborators being the set of principals who (the potential set of collaborators being the set of principals who
have write permission) and use a shared lock, which informs their have write permission) and use a shared lock, which informs their
collaborators that a principal may be working on the resource. collaborators that a principal may be working on the resource.
The WebDAV extensions to HTTP do not need to provide all of the The WebDAV extensions to HTTP do not need to provide all of the
communications paths necessary for principals to coordinate their communications paths necessary for principals to coordinate their
activities. When using shared locks, principals may use any out of activities. When using shared locks, principals may use any out of
band communication channel to coordinate their work (e.g., face-to- band communication channel to coordinate their work (e.g., face-to-
face interaction, written notes, post-it notes on the screen, face interaction, written notes, post-it notes on the screen,
telephone conversation, Email, etc.) The intent of a shared lock is telephone conversation, email, etc.) The intent of a shared lock is
to let collaborators know who else may be working on a resource. to let collaborators know who else may be working on a resource.
Shared locks are included because experience from web distributed Shared locks are included because experience from web distributed
authoring systems has indicated that exclusive locks are often too authoring systems has indicated that exclusive locks are often too
rigid. An exclusive lock is used to enforce a particular editing rigid. An exclusive lock is used to enforce a particular editing
process: take out an exclusive lock, read the resource, perform process: take out an exclusive lock, read the resource, perform
edits, write the resource, release the lock. This editing process edits, write the resource, release the lock. This editing process
has the problem that locks are not always properly released, for has the problem that locks are not always properly released, for
example when a program crashes, or when a lock owner leaves without example when a program crashes, or when a lock creator leaves without
unlocking a resource. While both timeouts and administrative action unlocking a resource. While both timeouts (Section 6.6) and
can be used to remove an offending lock, neither mechanism may be administrative action can be used to remove an offending lock,
available when needed; the timeout may be long or the administrator neither mechanism may be available when needed; the timeout may be
may not be available. long or the administrator may not be available.
6.2. Required Support A successful request for a new shared lock MUST result in the
generation of a unique lock associated with the requesting principal.
Thus if five principals have taken out shared write locks on the same
resource there will be five locks and five lock tokens, one for each
principal.
A WebDAV compliant server is not required to support locking in any 6.3. Required Support
form. If the server does support locking it may choose to support
A WebDAV compliant resource is not required to support locking in any
form. If the resource does support locking it may choose to support
any combination of exclusive and shared locks for any access types. any combination of exclusive and shared locks for any access types.
The reason for this flexibility is that locking policy strikes to the The reason for this flexibility is that locking policy strikes to the
very heart of the resource management and versioning systems employed very heart of the resource management and versioning systems employed
by various storage repositories. These repositories require control by various storage repositories. These repositories require control
over what sort of locking will be made available. For example, some over what sort of locking will be made available. For example, some
repositories only support shared write locks while others only repositories only support shared write locks while others only
provide support for exclusive write locks while yet others use no provide support for exclusive write locks while yet others use no
locking at all. As each system is sufficiently different to merit locking at all. As each system is sufficiently different to merit
exclusion of certain locking features, this specification leaves exclusion of certain locking features, this specification leaves
locking as the sole axis of negotiation within WebDAV. locking as the sole axis of negotiation within WebDAV.
6.3. Lock Tokens 6.4. Lock Creator and Privileges
A lock token is a type of state token, represented as a URI, which
identifies a particular lock. A lock token is returned by every
successful LOCK operation in the lockdiscovery property in the
response body, and can also be found through lock discovery on a
resource.
Lock token URIs MUST be unique across all resources for all time.
This uniqueness constraint allows lock tokens to be submitted across
resources and servers without fear of confusion.
This specification provides a lock token URI scheme called
opaquelocktoken that meets the uniqueness requirements. However
resources are free to return any URI scheme so long as it meets the
uniqueness requirements.
Having a lock token provides no special access rights. Anyone can
find out anyone else's lock token by performing lock discovery.
Locks MUST be enforced based upon whatever authentication mechanism
is used by the server, not based on the secrecy of the token values.
6.4. opaquelocktoken Lock Token URI Scheme
The opaquelocktoken URI scheme is designed to be unique across all
resources for all time. Due to this uniqueness quality, a client may
submit an opaque lock token in an If header on a resource other than
the one that returned it.
All resources MUST recognize the opaquelocktoken scheme and, at
minimum, recognize that the lock token does not refer to an
outstanding lock on the resource.
In order to guarantee uniqueness across all resources for all time The creator of a lock has special privileges to use the lock to
the opaquelocktoken requires the use of the Universal Unique modify the resource. When a locked resource is modified, a server
Identifier (UUID) mechanism, as described in [ISO-11578]. MUST check that the authenticated principal matches the lock creator
(in addition to checking for valid lock token submission).
Opaquelocktoken generators, however, have a choice of how they create The server MAY allow privileged users other than the lock creator to
these tokens. They can either generate a new UUID for every lock destroy a lock (for example, the resource owner or an administrator).
token they create or they can create a single UUID and then add The 'unlock' privilege in [RFC3744] was defined to provide that
extension characters. If the second method is selected then the permission.
program generating the extensions MUST guarantee that the same
extension will never be used twice with the associated UUID.
OpaqueLockToken-URI = "opaquelocktoken:" UUID [Extension] ; The UUID There is no requirement for servers to accept LOCK requests from all
production is the string representation of a UUID, as defined in users or from anonymous users.
[ISO-11578]. Note that white space (LWS) is not allowed between
elements of this production.
Extension = path ; path is defined in section 3.2.1 of RFC 2068 Note that having a lock does not confer full privilege to modify the
[RFC2068] locked resource. Write access and other privileges MUST be enforced
through normal privilege or authentication mechanisms, not based on
the possible obscurity of lock token values.
6.4.1. Node Field Generation Without the IEEE 802 Address 6.5. Lock Tokens
UUIDs, as defined in [ISO-11578], contain a "node" field that A lock token is a type of state token which identifies a particular
contains one of the IEEE 802 addresses for the server machine. As lock. Each lock has exactly one unique lock token generated by the
noted in Section 17.8, there are several security risks associated server. Clients MUST NOT attempt to interpret lock tokens in any
with exposing a machine's IEEE 802 address. This section provides an way.
alternate mechanism for generating the "node" field of a UUID which
does not employ an IEEE 802 address. WebDAV servers MAY use this
algorithm for creating the node field when generating UUIDs. The
text in this section is originally from an Internet-Draft by Paul
Leach and Rich Salz, who are noted here to properly attribute their
work.
The ideal solution is to obtain a 47 bit cryptographic quality random Lock token URIs MUST be unique across all resources for all time.
number, and use it as the low 47 bits of the node ID, with the most This uniqueness constraint allows lock tokens to be submitted across
significant bit of the first octet of the node ID set to 1. This bit resources and servers without fear of confusion. Since lock tokens
is the unicast/multicast bit, which will never be set in IEEE 802 are unique, a client MAY submit a lock token in an If header on a
addresses obtained from network cards; hence, there can never be a resource other than the one that returned it.
conflict between UUIDs generated by machines with and without network
cards.
If a system does not have a primitive to generate cryptographic When a LOCK operation creates a new lock, the new lock token is
quality random numbers, then in most systems there are usually a returned in the Lock-Token response header defined in Section 10.5,
fairly large number of sources of randomness available from which one and also in the body of the response.
can be generated. Such sources are system specific, but often
include:
o the percent of memory in use Servers MAY make lock tokens publicly readable (e.g. in the DAV:
lockdiscovery property). One use case for making lock tokens
readable is so that a long-lived lock can be removed by the resource
owner (the client that obtained the lock might have crashed or
disconnected before cleaning up the lock). Except for the case of
using UNLOCK under user guidance, a client SHOULD NOT use a lock
token created by another client instance.
o the size of main memory in bytes This specification encourages servers to create UUIDs for lock
tokens, and to use the URI form defined by "A Universally Unique
Identifier (UUID) URN Namespace" ([RFC4122]). However servers are
free to use any URI (e.g. from another scheme) so long as it meets
the uniqueness requirements. For example, a valid lock token might
be constructed using the "opaquelocktoken" scheme defined in
Appendix C.
o the amount of free main memory in bytes Example: "urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6"
o the size of the paging or swap file in bytes 6.6. Lock Timeout
o free bytes of paging or swap file A lock MAY have a limited lifetime. The lifetime is suggested by the
client when creating or refreshing the lock, but the server
ultimately chooses the timeout value. Timeout is measured in seconds
remaining until lock expiration.
o the total size of user virtual address space in bytes The timeout counter MUST be restarted if a refresh lock request is
successful (see Section 9.10.2). The timeout counter SHOULD NOT be
restarted at any other time.
o the total available user address space bytes If the timeout expires then the lock SHOULD be removed. In this case
the server SHOULD act as if an UNLOCK method was executed by the
server on the resource using the lock token of the timed-out lock,
performed with its override authority.
o the size of boot disk drive in bytes Servers are advised to pay close attention to the values submitted by
clients, as they will be indicative of the type of activity the
client intends to perform. For example, an applet running in a
browser may need to lock a resource, but because of the instability
of the environment within which the applet is running, the applet may
be turned off without warning. As a result, the applet is likely to
ask for a relatively small timeout value so that if the applet dies,
the lock can be quickly harvested. However, a document management
system is likely to ask for an extremely long timeout because its
user may be planning on going off-line.
o the free disk space on boot drive in bytes A client MUST NOT assume that just because the time-out has expired
the lock has immediately been removed.
o the current time Likewise, a client MUST NOT assume that just because the time-out has
not expired, the lock still exists. Clients MUST assume that locks
can arbitrarily disappear at any time, regardless of the value given
in the Timeout header. The Timeout header only indicates the
behavior of the server if extraordinary circumstances do not occur.
For example, a sufficiently privileged user may remove a lock at any
time or the system may crash in such a way that it loses the record
of the lock's existence.
o the amount of time since the system booted 6.7. Lock Capability Discovery
o the individual sizes of files in various system directories Since server lock support is optional, a client trying to lock a
resource on a server can either try the lock and hope for the best,
or perform some form of discovery to determine what lock capabilities
the server supports. This is known as lock capability discovery. A
client can determine what lock types the server supports by
retrieving the DAV:supportedlock property.
o the creation, last read, and modification times of files in Any DAV compliant resource that supports the LOCK method MUST support
various system directories the DAV:supportedlock property.
o the utilization factors of various system resources (heap, etc.) 6.8. Active Lock Discovery
o current mouse cursor position If another principal locks a resource that a principal wishes to
access, it is useful for the second principal to be able to find out
who the first principal is. For this purpose the DAV:lockdiscovery
property is provided. This property lists all outstanding locks,
describes their type, and MAY even provide the lock tokens.
o current caret position Any DAV compliant resource that supports the LOCK method MUST support
the DAV:lockdiscovery property.
o current number of running processes, threads 7. Write Lock
o handles or IDs of the desktop window and the active window This section describes the semantics specific to the write lock type.
The write lock is a specific instance of a lock type, and is the only
lock type described in this specification.
o the value of stack pointer of the caller An exclusive write lock protects a resource: it prevents changes by
any principal other than the lock creator and in any case where the
lock token is not submitted (e.g. by a client process other than the
one holding the lock).
o the process and thread ID of caller Clients MUST submit a lock-token they are authorized to use in any
request which modifies a write-locked resource. The list of
modifications covered by a write-lock include:
o various processor architecture specific performance counters 1. A change to any of the following aspects of any write-locked
(instructions executed, cache misses, TLB misses) resource:
(Note that it is precisely the above kinds of sources of randomness * any variant,
that are used to seed cryptographic quality random number generators
on systems without special hardware for their construction.)
In addition, items such as the computer's name and the name of the * any dead property,
operating system, while not strictly speaking random, will help
differentiate the results from those obtained by other systems.
The exact algorithm to generate a node ID using these data is system * any live property which is lockable (a live property is
specific, because both the data available and the functions to obtain lockable unless otherwise defined.)
them are often very system specific. However, assuming that one can
concatenate all the values from the randomness sources into a buffer,
and that a cryptographic hash function such as MD5 is available, then
any 6 bytes of the MD5 hash of the buffer, with the multicast bit
(the high bit of the first byte) set will be an appropriately random
node ID.
Other hash functions, such as SHA-1, can also be used. The only 2. For collections, any modification of an internal member URI. An
requirement is that the result be suitably random _ in the sense that internal member URI of a collection is considered to be modified
the outputs from a set uniformly distributed inputs are themselves if it is added, removed, or identifies a different resource.
uniformly distributed, and that a single bit change in the input can More discussion on write locks and collections is found in
be expected to cause half of the output bits to change. Section 7.4.
6.5. Lock Capability Discovery 3. A modification of the mapping of the root of the write lock,
either to another resource or to no resource (e.g. DELETE).
Since server lock support is optional, a client trying to lock a Of the methods defined in HTTP and WebDAV, PUT, POST, PROPPATCH,
resource on a server can either try the lock and hope for the best, LOCK, UNLOCK, MOVE, COPY (for the destination resource), DELETE, and
or perform some form of discovery to determine what lock capabilities MKCOL are affected by write locks. All other HTTP/WebDAV methods
the server supports. This is known as lock capability discovery. defined so far, GET in particular, function independently of a write
Lock capability discovery differs from discovery of supported access lock.
control types, since there may be access control types without
corresponding lock types. A client can determine what lock types the
server supports by retrieving the supportedlock property.
Any DAV compliant resource that supports the LOCK method MUST support The next few sections describe in more specific terms how write locks
the supportedlock property. interact with various operations.
6.6. Active Lock Discovery 7.1. Write Locks and Properties
If another principal locks a resource that a principal wishes to While those without a write lock may not alter a property on a
access, it is useful for the second principal to be able to find out resource it is still possible for the values of live properties to
who the first principal is. For this purpose the lockdiscovery change, even while locked, due to the requirements of their schemas.
property is provided. This property lists all outstanding locks,
describes their type, and where available, provides their lock token.
Any DAV compliant resource that supports the LOCK method MUST support Only dead properties and live properties defined as lockable are
the lockdiscovery property. guaranteed not to change while write locked.
6.7. Usage Considerations 7.2. Avoiding Lost Updates
Although the locking mechanisms specified here provide some help in Although the write locks provide some help in preventing lost
preventing lost updates, they cannot guarantee that updates will updates, they cannot guarantee that updates will never be lost.
never be lost. Consider the following scenario: Consider the following scenario:
Two clients A and B are interested in editing the resource ' Two clients A and B are interested in editing the resource
index.html'. Client A is an HTTP client rather than a WebDAV client, 'index.html'. Client A is an HTTP client rather than a WebDAV
and so does not know how to perform locking. client, and so does not know how to perform locking.
Client A doesn't lock the document, but does a GET and begins Client A doesn't lock the document, but does a GET and begins
editing. editing.
Client B does LOCK, performs a GET and begins editing. Client B does LOCK, performs a GET and begins editing.
Client B finishes editing, performs a PUT, then an UNLOCK. Client B finishes editing, performs a PUT, then an UNLOCK.
Client A performs a PUT, overwriting and losing all of B's changes. Client A performs a PUT, overwriting and losing all of B's changes.
skipping to change at page 21, line 5 skipping to change at page 29, line 5
they interact with a WebDAV server that supports locking. they interact with a WebDAV server that supports locking.
HTTP 1.1 clients can be good citizens, avoiding overwriting other HTTP 1.1 clients can be good citizens, avoiding overwriting other
clients' changes, by using entity tags in If-Match headers with any clients' changes, by using entity tags in If-Match headers with any
requests that would modify resources. requests that would modify resources.
Information managers may attempt to prevent overwrites by Information managers may attempt to prevent overwrites by
implementing client-side procedures requiring locking before implementing client-side procedures requiring locking before
modifying WebDAV resources. modifying WebDAV resources.
7. Write Lock 7.3. Write Locks and Unmapped URLs
This section describes the semantics specific to the write lock type. WebDAV provides the ability to send a LOCK request to an unmapped URL
The write lock is a specific instance of a lock type, and is the only in order to reserve the name for use. This is a simple way to avoid
lock type described in this specification. the lost-update problem on the creation of a new resource (another
way is to use If-None-Match header specified in Section 14.26 of
[RFC2616]). It has the side benefit of locking the new resource
immediately for use of the creator.
7.1. Methods Restricted by Write Locks Note that the lost-update problem is not an issue for collections
because MKCOL can only be used to create a collection, not to
overwrite an existing collection. When trying to lock a collection
upon creation, clients can attempt to increase the likelihood of
getting the lock by pipelining the MKCOL and LOCK requests together
(but because this doesn't convert two separate operations into one
atomic operation there's no guarantee this will work).
A write lock MUST prevent a principal without the lock from A successful lock request to an unmapped URL MUST result in the
successfully executing a PUT, POST, PROPPATCH, LOCK, UNLOCK, MOVE, creation of a locked (non-collection) resource with empty content.
DELETE, or MKCOL on the locked resource. All other current methods, Subsequently, a successful PUT request (with the correct lock token)
GET in particular, function independently of the lock. provides the content for the resource. Note that the LOCK request
has no mechanism for the client to provide Content-Type or Content-
Language, thus the server will use defaults or empty values and rely
on the subsequent PUT request for correct values.
Note, however, that as new methods are created it will be necessary A resource created with a LOCK is empty but otherwise behaves in
to specify how they interact with a write lock. every way as a normal resource. It behaves the same way as a
resource created by a PUT request with an empty body (and where a
Content-Type and Content-Language was not specified), followed by a
LOCK request to the same resource. Following from this model, a
locked empty resource:
7.2. Write Locks and Lock Tokens o Can be read, deleted, moved, copied, and in all ways behave as a
regular non-collection resource.
A successful request for an exclusive or shared write lock MUST o Appears as a member of its parent collection.
result in the generation of a unique lock token associated with the
requesting principal. Thus if five principals have a shared write
lock on the same resource there will be five lock tokens, one for
each principal.
7.3. Write Locks and Properties o SHOULD NOT disappear when its lock goes away (clients must
therefore be responsible for cleaning up their own mess, as with
any other operation or any non-empty resource)
While those without a write lock may not alter a property on a o MAY NOT have values for properties like DAV:getcontentlanguage
resource it is still possible for the values of live properties to which haven't been specified yet by the client.
change, even while locked, due to the requirements of their schemas.
Only dead properties and live properties defined to respect locks are
guaranteed not to change while write locked.
7.4. Write Locks and Null Resources o Can be updated (have content added) with a PUT request.
It is possible to assert a write lock on a null resource in order to o MUST NOT be converted into a collection. The server MUST fail a
lock the name. MKCOL request (as it would with a MKCOL request to any existing
non-collection resource).
A write locked null resource, referred to as a lock-null resource, o MUST have defined values for DAV:lockdiscovery and DAV:
MUST respond with a 404 (Not Found) or 405 (Method Not Allowed) to supportedlock properties.
any HTTP/1.1 or DAV methods except for PUT, MKCOL, OPTIONS, PROPFIND,
LOCK, and UNLOCK. A lock-null resource MUST appear as a member of
its parent collection. Additionally the lock-null resource MUST have
defined on it all mandatory DAV properties. Most of these
properties, such as all the get* properties, will have no value as a
lock-null resource does not support the GET method. Lock-Null
resources MUST have defined values for lockdiscovery and
supportedlock properties.
Until a method such as PUT or MKCOL is successfully executed on the o The response MUST indicate that a resource was created, by use of
lock-null resource the resource MUST stay in the lock-null state. the "201 Created" response code (a LOCK request to an existing
However, once a PUT or MKCOL is successfully executed on a lock-null resource instead will result in 200 OK). The body must still
resource the resource ceases to be in the lock-null state. include the DAV:lockdiscovery property, as with a LOCK request to
an existing resource.
If the resource is unlocked, for any reason, without a PUT, MKCOL, or The client is expected to update the locked empty resource shortly
similar method having been successfully executed upon it then the after locking it, using PUT and possibly PROPPATCH.
resource MUST return to the null state.
7.5. Write Locks and Collections Alternatively and for backwards compatibility to [RFC2518], servers
MAY implement Lock-Null Resources (LNRs) instead (see definition in
Appendix D). Clients can easily interoperate both with servers that
support the old model LNRs and the recommended model of "locked empty
resources" by only attempting PUT after a LOCK to an unmapped URL,
not MKCOL or GET, and by not relying on specific properties of LNRs.
A write lock on a collection, whether created by a "Depth: 0" or 7.4. Write Locks and Collections
"Depth: infinity" lock request, prevents the addition or removal of
member URIs of the collection by non-lock owners. As a consequence,
when a principal issues a PUT or POST request to create a new
resource under a URI which needs to be an internal member of a write
locked collection to maintain HTTP namespace consistency, or issues a
DELETE to remove a resource which has a URI which is an existing
internal member URI of a write locked collection, this request MUST
fail if the principal does not have a write lock on the collection.
However, if a write lock request is issued to a collection containing There are two kinds of collection write locks. A depth-0 write lock
member URIs identifying resources that are currently locked in a on a collection protects the collection properties plus the internal
manner which conflicts with the write lock, the request MUST fail member URLs of that one collection, while not protecting the content
with a 423 (Locked) status code. or properties of member resources (if the collection itself has any
entity bodies, those are also protected). A depth-infinity write
lock on a collection provides the same protection on that collection
and also provides write lock protection on every member resource.
If a lock owner causes the URI of a resource to be added as an Expressed otherwise, a write lock protects any request that would
internal member URI of a locked collection then the new resource MUST create a new resource in a write locked collection, any request that
be automatically added to the lock. This is the only mechanism that would remove an internal member URL of a write locked collection, and
allows a resource to be added to a write lock. Thus, for example, if any request that would change the segment name of any internal
the collection /a/b/ is write locked and the resource /c is moved to member.
/a/b/c then resource /a/b/c will be added to the write lock.
7.6. Write Locks and the If Request Header Thus, a collection write lock protects all the following actions:
If a user agent is not required to have knowledge about a lock when o DELETE a collection's direct internal member,
requesting an operation on a locked resource, the following scenario
might occur. Program A, run by User A, takes out a write lock on a o MOVE an internal member out of the collection,
resource. Program B, also run by User A, has no knowledge of the
lock taken out by Program A, yet performs a PUT to the locked o MOVE an internal member into the collection,
resource. In this scenario, the PUT succeeds because locks are
associated with a principal, not a program, and thus program B, o MOVE to rename an internal member within a collection,
because it is acting with principal A's credential, is allowed to o COPY an internal member into a collection, and
perform the PUT. However, had program B known about the lock, it
would not have overwritten the resource, preferring instead to o PUT or MKCOL request which would create a new internal member.
present a dialog box describing the conflict to the user. Due to
The collection's lock token is required in addition to the lock token
on the internal member itself, if it is locked separately.
In addition, a depth-infinity lock affects all write operations to
all members of the locked collection. With a depth-infinity lock,
the resource identified by the root of the lock is directly locked,
and all its members are indirectly locked.
o Any new resource added as a descendent of a depth-infinity locked
collection becomes indirectly locked.
o Any indirectly locked resource moved out of the locked collection
into an unlocked collection is thereafter unlocked.
o Any indirectly locked resource moved out of a locked source
collection into a depth-infinity locked target collection remains
indirectly locked but is now protected by the lock on the target
collection (the target collection's lock token will thereafter be
required to make further changes).
If a depth-infinity write LOCK request is issued to a collection
containing member URLs identifying resources that are currently
locked in a manner which conflicts with the new lock (see Section 6.1
point 3), the request MUST fail with a 423 (Locked) status code, and
the response SHOULD contain the 'no-conflicting-lock' precondition.
If a lock request causes the URL of a resource to be added as an
internal member URL of a depth-infinity locked collection then the
new resource MUST be automatically protected by the lock. For
example, if the collection /a/b/ is write locked and the resource /c
is moved to /a/b/c then resource /a/b/c will be added to the write
lock.
7.5. Write Locks and the If Request Header
A user agent has to demonstrate knowledge of a lock when requesting
an operation on a locked resource. Otherwise, the following scenario
might occur. In the scenario, program A, run by User A, takes out a
write lock on a resource. Program B, also run by User A, has no
knowledge of the lock taken out by program A, yet performs a PUT to
the locked resource. In this scenario, the PUT succeeds because
locks are associated with a principal, not a program, and thus
program B, because it is acting with principal A's credential, is
allowed to perform the PUT. However, had program B known about the
lock, it would not have overwritten the resource, preferring instead
to present a dialog box describing the conflict to the user. Due to
this scenario, a mechanism is needed to prevent different programs this scenario, a mechanism is needed to prevent different programs
from accidentally ignoring locks taken out by other programs with the from accidentally ignoring locks taken out by other programs with the
same authorization. same authorization.
In order to prevent these collisions a lock token MUST be submitted In order to prevent these collisions a lock token MUST be submitted
by an authorized principal in the If header for all locked resources by an authorized principal for all locked resources that a method may
that a method may interact with or the method MUST fail. For change or the method MUST fail. A lock token is submitted when it
example, if a resource is to be moved and both the source and appears in an If header. For example, if a resource is to be moved
destination are locked then two lock tokens must be submitted, one and both the source and destination are locked then two lock tokens
for the source and the other for the destination. must be submitted in the If header, one for the source and the other
for the destination.
7.6.1. Example - Write Lock 7.5.1. Example - Write Lock and COPY
>>Request >>Request
COPY /~fielding/index.html HTTP/1.1 COPY /~fielding/index.html HTTP/1.1
Host: www.ics.uci.edu Host: www.example.com
Destination: http://www.ics.uci.edu/users/f/fielding/index.html Destination: http://www.example.com/users/f/fielding/index.html
If: <http://www.ics.uci.edu/users/f/fielding/index.html> If: <http://www.example.com/users/f/fielding/index.html>
(<opaquelocktoken:f81d4fae-7dec-11d0-a765-00a0c91e6bf6>) (<urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6>)
>>Response >>Response
HTTP/1.1 204 No Content HTTP/1.1 204 No Content
In this example, even though both the source and destination are In this example, even though both the source and destination are
locked, only one lock token must be submitted, for the lock on the locked, only one lock token must be submitted, for the lock on the
destination. This is because the source resource is not modified by destination. This is because the source resource is not modified by
a COPY, and hence unaffected by the write lock. In this example, a COPY, and hence unaffected by the write lock. In this example,
user agent authentication has previously occurred via a mechanism user agent authentication has previously occurred via a mechanism
outside the scope of the HTTP protocol, in the underlying transport outside the scope of the HTTP protocol, in the underlying transport
layer. layer.
7.7. Write Locks and COPY/MOVE 7.5.2. Example - Deleting a Member of a Locked Collection
Consider a collection "/locked" with an exclusive, depth-infinity
write lock, and an attempt to delete an internal member "/locked/
member":
>>Request
DELETE /locked/member HTTP/1.1
Host: example.com
>>Response
HTTP/1.1 423 Locked
Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:error xmlns:D="DAV:">
<D:lock-token-submitted>
<D:href>/locked/</D:href>
</D:lock-token-submitted>
</D:error>
Thus the client would need to submit the lock token with the request
to make it succeed. To do that, various forms of the If header (see
Section 10.4) could be used.
"No-Tag-List" format:
If: (<urn:uuid:150852e2-3847-42d5-8cbe-0f4f296f26cf>)
"Tagged-List" format, for "http://example.com/locked/":
If: <http://example.com/locked/>
(<urn:uuid:150852e2-3847-42d5-8cbe-0f4f296f26cf>)
"Tagged-List" format, for "http://example.com/locked/member":
If: <http://example.com/locked/member>
(<urn:uuid:150852e2-3847-42d5-8cbe-0f4f296f26cf>)
Note that for the purpose of submitting the lock token the actual
form doesn't matter; what's relevant is that the lock token appears
in the If header, and that the If header itself evaluates to true.
7.6. Write Locks and COPY/MOVE
A COPY method invocation MUST NOT duplicate any write locks active on A COPY method invocation MUST NOT duplicate any write locks active on
the source. However, as previously noted, if the COPY copies the the source. However, as previously noted, if the COPY copies the
resource into a collection that is locked with "Depth: infinity", resource into a collection that is locked with a depth-infinity lock,
then the resource will be added to the lock. then the resource will be added to the lock.
A successful MOVE request on a write locked resource MUST NOT move A successful MOVE request on a write locked resource MUST NOT move
the write lock with the resource. However, the resource is subject the write lock with the resource. However, if there is an existing
to being added to an existing lock at the destination, as specified lock at the destination, the server MUST add the moved resource to
in Section 7.5. For example, if the MOVE makes the resource a child the destination lock scope. For example, if the MOVE makes the
of a collection that is locked with "Depth: infinity", then the resource a child of a collection that has a depth-infinity lock, then
resource will be added to that collection's lock. Additionally, if a the resource will be added to that collection's lock. Additionally,
resource locked with "Depth: infinity" is moved to a destination that if a resource with a depth-infinity lock is moved to a destination
is within the scope of the same lock (e.g., within the namespace tree that is within the scope of the same lock (e.g., within the URL
covered by the lock), the moved resource will again be a added to the namespace tree covered by the lock), the moved resource will again be
lock. In both these examples, as specified in Section 7.6, an If a added to the lock. In both these examples, as specified in
header must be submitted containing a lock token for both the source Section 7.5, an If header must be submitted containing a lock token
and destination. for both the source and destination.
7.8. Refreshing Write Locks 7.7. Refreshing Write Locks
A client MUST NOT submit the same write lock request twice. Note A client MUST NOT submit the same write lock request twice. Note
that a client is always aware it is resubmitting the same lock that a client is always aware it is resubmitting the same lock
request because it must include the lock token in the If header in request because it must include the lock token in the If header in
order to make the request for a resource that is already locked. order to make the request for a resource that is already locked.
However, a client may submit a LOCK method with an If header but However, a client may submit a LOCK request with an If header but
without a body. This form of LOCK MUST only be used to "refresh" a without a body. A server receiving a LOCK request with no body MUST
lock. Meaning, at minimum, that any timers associated with the lock NOT create a new lock -- this form of the LOCK request is only to be
MUST be re-set. used to "refresh" an existing lock (meaning, at minimum, that any
timers associated with the lock MUST be re-set).
A server may return a Timeout header with a lock refresh that is Clients may submit Timeout headers of arbitrary value with their lock
different than the Timeout header returned when the lock was refresh requests. Servers, as always, may ignore Timeout headers
originally requested. Additionally clients may submit Timeout submitted by the client, and a server MAY refresh a lock with a
headers of arbitrary value with their lock refresh requests. timeout period that is different than the previous timeout period
Servers, as always, may ignore Timeout headers submitted by the used for the lock, provided it advertises the new value in the LOCK
client. refresh response.
If an error is received in response to a refresh LOCK request the If an error is received in response to a refresh LOCK request the
client SHOULD assume that the lock was not refreshed. client MUST NOT assume that the lock was refreshed.
8. HTTP Methods for Distributed Authoring 8. General Request and Response Handling
The following new HTTP methods use XML as a request and response 8.1. Precedence in Error Handling
format. All DAV compliant clients and resources MUST use XML parsers
that are compliant with [REC-XML]. All XML used in either requests
or responses MUST be, at minimum, well formed. If a server receives
ill-formed XML in a request it MUST reject the entire request with a
400 (Bad Request). If a client receives ill-formed XML in a response
then it MUST NOT assume anything about the outcome of the executed
method and SHOULD treat the server as malfunctioning.
8.1. PROPFIND Servers MUST return authorization errors in preference to other
errors. This avoids leaking information about protected resources
(e.g. a client that finds that a hidden resource exists by seeing a
423 Locked response to an anonymous request to the resource).
8.2. Use of XML
In HTTP/1.1, method parameter information was exclusively encoded in
HTTP headers. Unlike HTTP/1.1, WebDAV encodes method parameter
information either in an XML ([REC-XML]) request entity body, or in
an HTTP header. The use of XML to encode method parameters was
motivated by the ability to add extra XML elements to existing
structures, providing extensibility; and by XML's ability to encode
information in ISO 10646 character sets, providing
internationalization support.
In addition to encoding method parameters, XML is used in WebDAV to
encode the responses from methods, providing the extensibility and
internationalization advantages of XML for method output, as well as
input.
When XML is used for a request or response body, the Content-Type
type SHOULD be application/xml. Implementations MUST accept both
text/xml and application/xml in request and response bodies. Use of
text/xml is deprecated.
All DAV compliant clients and resources MUST use XML parsers that are
compliant with [REC-XML] and [REC-XML-NAMES]. All XML used in either
requests or responses MUST be, at minimum, well formed and use
namespaces correctly. If a server receives XML that is not well-
formed then the server MUST reject the entire request with a 400 (Bad
Request). If a client receives XML that is not well-formed in a
response then the client MUST NOT assume anything about the outcome
of the executed method and SHOULD treat the server as malfunctioning.
Note that processing XML submitted by an untrusted source may cause
risks connected to privacy, security, and service quality (see
Section 20). Servers MAY reject questionable requests (even though
they consist of well-formed XML), for instance with a 400 (Bad
Request) status code and an optional response body explaining the
problem.
8.3. URL Handling
URLs appear in many places in requests and responses.
Interoperability experience with [RFC2518] showed that many clients
parsing Multi-Status responses did not fully implement the full
Reference Resolution defined in Section 5 of [RFC3986]. Thus,
servers in particular need to be careful in handling URLs in
responses, to ensure that clients have enough context to be able to
interpret all the URLs. The rules in this section apply not only to
resource URLs in the 'href' element in Multi-Status responses, but
also to the Destination and If header resource URLs.
The sender has a choice between two approaches: using a relative
reference, which is resolved against the Request-URI, or a full URI.
A server MUST ensure that every 'href' value within a Multi-Status
response uses the same format.
WebDAV only uses one form of relative reference in its extensions,
the absolute path.
Simple-ref = absolute-URI | ( path-absolute [ "?" query ] )
The absolute-URI, path-absolute and query productions are defined in
Section 4.3, 3.3 and 3.4 of [RFC3986].
Within Simple-ref productions, senders MUST NOT:
o use dot-segments ("." or ".."), or
o have prefixes that do not match the Request-URI (using the
comparison rules defined in Section 3.2.3 of [RFC2616]).
Identifiers for collections SHOULD end in a '/' character.
8.3.1. Example - Correct URL Handling
Consider the collection http://example.com/sample/ with the internal
member URL http://example.com/sample/a%20test and the PROPFIND
request below:
>>Request:
PROPFIND /sample/ HTTP/1.1
Host: example.com
Depth: 1
In this case, the server should return two 'href' elements containing
either
o 'http://example.com/sample/' and
'http://example.com/sample/a%20test', or
o '/sample/' and '/sample/a%20test'
Note that even though the server may be storing the member resource
internally as 'a test', it has to be percent-encoded when used inside
a URI reference (see Section 2.1 of [RFC3986]). Also note that a
legal URI may still contain characters that need to be escaped within
XML character data, such as the ampersand character.
8.4. Required Bodies in Requests
Some of these new methods do not define bodies. Servers MUST examine
all requests for a body, even when a body was not expected. In cases
where a request body is present but would be ignored by a server, the
server MUST reject the request with 415 (Unsupported Media Type).
This informs the client (which may have been attempting to use an
extension) that the body could not be processed as the client
intended.
8.5. HTTP Headers for use in WebDAV
HTTP defines many headers that can be used in WebDAV requests and
responses. Not all of these are appropriate in all situations and
some interactions may be undefined. Note that HTTP 1.1 requires the
Date header in all responses if possible (see Section 14.18,
[RFC2616]).
The server MUST do authorization checks before checking any HTTP
conditional header.
8.6. ETag
HTTP 1.1 recommends the use of ETags rather than modification dates,
for cache-control, and there are even stronger reasons to prefer
ETags for authoring. Correct use of ETags is even more important in
a distributed authoring environment, because ETags are necessary
along with locks to avoid the lost-update problem. A client might
fail to renew a lock, for example when the lock times out and the
client is accidentally offline or in the middle of a long upload.
When a client fails to renew the lock, it's quite possible the
resource can still be relocked and the user can go on editing, as
long as no changes were made in the meantime. ETags are required for
the client to be able to distinguish this case. Otherwise, the
client is forced to ask the user whether to overwrite the resource on
the server without even being able to tell the user whether it has
changed. Timestamps do not solve this problem nearly as well as
ETags.
Strong ETags are much more useful for authoring use cases than weak
ETags (see Section 13.3.3 of [RFC2616]). Semantic equivalence can be
a useful concept but that depends on the document type and the
application type, and interoperability might require some agreement
or standard outside the scope of this specification and HTTP. Note
also that weak ETags have certain restrictions in HTTP, e.g. these
cannot be used in If-Match headers.
Note that the meaning of an ETag in a PUT response is not clearly
defined either in this document or in RFC2616 (i.e., whether the ETag
means that the resource is octet-for-octet equivalent to the body of
the PUT request, or whether the server could have made minor changes
in the formatting or content of the document upon storage). This is
an HTTP issue, not purely a WebDAV issue.
Because clients may be forced to prompt users or throw away changed
content if the ETag changes, a WebDAV server SHOULD NOT change the
ETag (or the Last-Modified time) for a resource that has an unchanged
body and location. The ETag represents the state of the body or
contents of the resource. There is no similar way to tell if
properties have changed.
8.7. Including Error Response Bodies
HTTP and WebDAV did not use the bodies of most error responses for
machine-parsable information until the specification for Versioning
Extensions to WebDAV introduced a mechanism to include more specific
information in the body of an error response (Section 1.6 of
[RFC3253]). The error body mechanism is appropriate to use with any
error response that may take a body but does not already have a body
defined. The mechanism is particularly appropriate when a status
code can mean many things (for example, 400 Bad Request can mean
required headers are missing, headers are incorrectly formatted, or
much more). This error body mechanism is covered in Section 16.
8.8. Impact of Namespace Operations on Cache Validators
Note that the HTTP response headers "Etag" and "Last-Modified" (see
[RFC2616], Sections 14.19 and 14.29) are defined per URL (not per
resource), and are used by clients for caching. Therefore servers
must ensure that executing any operation that affects the URL
namespace (such as COPY, MOVE, DELETE, PUT or MKCOL) does preserve
their semantics, in particular:
o For any given URL, the "Last-Modified" value MUST increment every
time the representation returned upon GET changes (within the
limits of timestamp resolution).
o For any given URL, an "ETag" value MUST NOT be re-used for
different representations returned by GET.
In practice this means that servers
o might have to increment "Last-Modified" timestamps for every
resource inside the destination namespace of a namespace operation
unless it can do so more selectively, and
o similarily, might have to re-assign "ETag" values for these
resources (unless the server allocates entity tags in a way so
that they are unique across the whole URL namespace managed by the
server).
Note that these considerations also apply to specific use cases, such
as using PUT to create a new resource at a URL that has been mapped
before, but has been deleted since then.
Finally, WebDAV properties (such as DAV:getetag and DAV:
getlastmodified) that inherit their semantics from HTTP headers must
behave accordingly.
9. HTTP Methods for Distributed Authoring
9.1. PROPFIND Method
The PROPFIND method retrieves properties defined on the resource The PROPFIND method retrieves properties defined on the resource
identified by the Request-URI, if the resource does not have any identified by the Request-URI, if the resource does not have any
internal members, or on the resource identified by the Request-URI internal members, or on the resource identified by the Request-URI
and potentially its member resources, if the resource is a collection and potentially its member resources, if the resource is a collection
that has internal member URIs. All DAV compliant resources MUST that has internal member URLs. All DAV compliant resources MUST
support the PROPFIND method and the propfind XML element (section support the PROPFIND method and the propfind XML element
12.14) along with all XML elements defined for use with that element. (Section 14.20) along with all XML elements defined for use with that
element.
A client may submit a Depth header with a value of "0", "1", or A client MUST submit a Depth header with a value of "0", "1", or
"infinity" with a PROPFIND on a collection resource with internal "infinity" with a PROPFIND request. Servers MUST support "0" and "1"
member URIs. DAV compliant servers MUST support the "0", "1" and depth requests on WebDAV-compliant resources and SHOULD support
"infinity" behaviors. By default, the PROPFIND method without a "infinity" requests. In practice, support for infinite depth
Depth header MUST act as if a "Depth: infinity" header was included. requests MAY be disabled, due to the performance and security
concerns associated with this behavior. Since clients weren't
required to include the Depth header in [RFC2518], servers SHOULD
treat such a request as if a "Depth: infinity" header was included.
A client may submit a propfind XML element in the body of the request A client may submit a 'propfind' XML element in the body of the
method describing what information is being requested. It is request method describing what information is being requested. It is
possible to request particular property values, all property values, possible to:
or a list of the names of the resource's properties. A client may
choose not to submit a request body. An empty PROPFIND request body o Request particular property values, by naming the properties
MUST be treated as a request for the names and values of all desired within the 'prop' element (the ordering of properties in
properties. here MAY be ignored by server),
o Request property values for those properties defined in this
specification (at a minimum) plus dead properties, by using the
'allprop' element (the 'include' element can be used with
'allprop' to instruct the server to also include additional live
properties that may not have been returned otherwise),
o Request a list of names of all the properties defined on the
resource, by using the 'propname' element.
A client may choose not to submit a request body. An empty PROPFIND
request body MUST be treated as if it were an 'allprop' request.
Note that 'allprop' does not return values for all live properties.
WebDAV servers increasingly have expensively-calculated or lengthy
properties (see [RFC3253] and [RFC3744]) and do not return all
properties already. Instead, WebDAV clients can use propname
requests to discover what live properties exist, and request named
properties when retrieving values. For a live property defined
elsewhere, that definition can specify whether that live property
would be returned in 'allprop' requests or not.
All servers MUST support returning a response of content type text/ All servers MUST support returning a response of content type text/
xml or application/xml that contains a multistatus XML element that xml or application/xml that contains a multistatus XML element that
describes the results of the attempts to retrieve the various describes the results of the attempts to retrieve the various
properties. properties.
If there is an error retrieving a property then a proper error result If there is an error retrieving a property then a proper error result
MUST be included in the response. A request to retrieve the value of MUST be included in the response. A request to retrieve the value of
a property which does not exist is an error and MUST be noted, if the a property which does not exist is an error and MUST be noted with a
response uses a multistatus XML element, with a response XML element 'response' XML element which contains a 404 (Not Found) status value.
which contains a 404 (Not Found) status value.
Consequently, the multistatus XML element for a collection resource Consequently, the 'multistatus' XML element for a collection resource
with member URIs MUST include a response XML element for each member MUST include a 'response' XML element for each member URL of the
URI of the collection, to whatever depth was requested. Each collection, to whatever depth was requested. It SHOULD NOT include
response XML element MUST contain an href XML element that gives the any 'response' elements for resources that are not WebDAV-compliant.
URI of the resource on which the properties in the prop XML element Each 'response' element MUST contain an 'href' element that contains
are defined. Results for a PROPFIND on a collection resource with the URL of the resource on which the properties in the prop XML
internal member URIs are returned as a flat list whose order of element are defined. Results for a PROPFIND on a collection resource
entries is not significant. are returned as a flat list whose order of entries is not
significant. Note that a resource may have only one value for a
property of a given name, so the property may only show up once in
PROPFIND responses.
In the case of allprop and propname, if a principal does not have the Properties may be subject to access control. In the case of
'allprop' and 'propname' requests, if a principal does not have the
right to know whether a particular property exists then the property right to know whether a particular property exists then the property
should be silently excluded from the response. MAY be silently excluded from the response.
The results of this method SHOULD NOT be cached. Some PROPFIND results MAY be cached, with care as there is no cache
validation mechanism for most properties. This method is both safe
and idempotent (see Section 9.1 of [RFC2616]).
8.1.1. Example - Retrieving Named Properties 9.1.1. PROPFIND Status Codes
>>Request This section, as with similar sections for other methods, provides
some guidance on error codes and preconditions or postconditions
(defined in Section 16) that might be particularly useful with
PROPFIND.
PROPFIND /file HTTP/1.1 403 Forbidden - A server MAY reject PROPFIND requests on collections
Host: www.foo.bar with depth header of "Infinity", in which case it SHOULD use this
Content-type: text/xml; charset="utf-8" error with the precondition code 'propfind-finite-depth' inside the
Content-Length: xxxx error body.
<?xml version="1.0" encoding="utf-8" ?> 9.1.2. Status Codes for Use in 'propstat' Element
<D:propfind xmlns:D="DAV:">
<D:prop xmlns:R="http://www.foo.bar/boxschema/">
<R:bigbox/>
<R:author/>
<R:DingALing/>
<R:Random/>
</D:prop>
</D:propfind>
>>Response In PROPFIND responses, information about individual properties is
returned inside 'propstat' elements (see Section 14.22), each
containing an individual 'status' element containing information
about the properties appearing in it. The list below summarizes the
most common status codes used inside 'propstat', however clients
should be prepared to handle other 2/3/4/5xx series status codes as
well.
HTTP/1.1 207 Multi-Status 200 OK - A property exists and/or its value is successfully returned.
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> 401 Unauthorized - The property cannot be viewed without appropriate
<D:multistatus xmlns:D="DAV:"> authorization.
<D:response>
<D:href>http://www.foo.bar/file</D:href>
<D:propstat>
<D:prop xmlns:R="http://www.foo.bar/boxschema/">
<R:bigbox>
<R:BoxType>Box type A</R:BoxType>
</R:bigbox>
<R:author>
<R:Name>J.J. Johnson</R:Name>
</R:author>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
<D:propstat>
<D:prop><R:DingALing/><R:Random/></D:prop>
<D:status>HTTP/1.1 403 Forbidden</D:status>
<D:responsedescription> The user does not have access to
the DingALing property.
</D:responsedescription>
</D:propstat>
</D:response>
<D:responsedescription> There has been an access violation error.
</D:responsedescription>
</D:multistatus>
In this example, PROPFIND is executed on a non-collection resource 403 Forbidden - The property cannot be viewed regardless of
http://www.foo.bar/file. The propfind XML element specifies the name authentication.
of four properties whose values are being requested. In this case
only two properties were returned, since the principal issuing the
request did not have sufficient access rights to see the third and
fourth properties.
8.1.2. Example - Using allprop to Retrieve All Properties 404 Not Found - The property does not exist.
9.1.3. Example - Retrieving Named Properties
>>Request >>Request
PROPFIND /container/ HTTP/1.1 PROPFIND /file HTTP/1.1
Host: www.foo.bar Host: www.example.com
Depth: 1 Content-type: application/xml; charset="utf-8"
Content-Type: text/xml; charset="utf-8" Content-Length: xxxx
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:"> <D:propfind xmlns:D="DAV:">
<D:allprop/> <D:prop xmlns:R="http://ns.example.com/boxschema/">
</D:propfind> <R:bigbox/>
<R:author/>
<R:DingALing/>
<R:Random/>
</D:prop>
</D:propfind>
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"> <D:multistatus xmlns:D="DAV:">
<D:response> <D:response xmlns:R="http://ns.example.com/boxschema/">
<D:href>http://www.foo.bar/container/</D:href> <D:href>http://www.example.com/file</D:href>
<D:propstat> <D:propstat>
<D:prop xmlns:R="http://www.foo.bar/boxschema/"> <D:prop>
<R:bigbox> <R:bigbox>
<R:BoxType>Box type A</R:BoxType> <R:BoxType>Box type A</R:BoxType>
</R:bigbox> </R:bigbox>
<R:author> <R:author>
<R:Name>Hadrian</R:Name> <R:Name>J.J. Johnson</R:Name>
</R:author> </R:author>
<D:creationdate> </D:prop>
1997-12-01T17:42:21-08:00 <D:status>HTTP/1.1 200 OK</D:status>
</D:creationdate> </D:propstat>
<D:displayname> <D:propstat>
Example collection <D:prop><R:DingALing/><R:Random/></D:prop>
</D:displayname> <D:status>HTTP/1.1 403 Forbidden</D:status>
<D:resourcetype><D:collection/></D:resourcetype> <D:responsedescription> The user does not have access to the
<D:supportedlock> DingALing property.
<D:lockentry> </D:responsedescription>
<D:lockscope><D:exclusive/></D:lockscope> </D:propstat>
<D:locktype><D:write/></D:locktype> </D:response>
</D:lockentry> <D:responsedescription> There has been an access violation error.
<D:lockentry> </D:responsedescription>
<D:lockscope><D:shared/></D:lockscope> </D:multistatus>
<D:locktype><D:write/></D:locktype>
</D:lockentry> In this example, PROPFIND is executed on a non-collection resource
</D:supportedlock> http://www.example.com/file. The propfind XML element specifies the
</D:prop> name of four properties whose values are being requested. In this
<D:status>HTTP/1.1 200 OK</D:status> case only two properties were returned, since the principal issuing
</D:propstat> the request did not have sufficient access rights to see the third
</D:response> and fourth properties.
<D:response>
<D:href>http://www.foo.bar/container/front.html</D:href>
<D:propstat>
<D:prop xmlns:R="http://www.foo.bar/boxschema/">
<R:bigbox>
<R:BoxType>Box type B</R:BoxType>
</R:bigbox>
<D:creationdate>
1997-12-01T18:27:21-08:00
</D:creationdate>
<D:displayname>
Example HTML resource
</D:displayname>
<D:getcontentlength>
4525
</D:getcontentlength>
<D:getcontenttype>
text/html
</D:getcontenttype>
<D:getetag>
zzyzx
</D:getetag>
<D:getlastmodified>
Monday, 12-Jan-98 09:25:56 GMT
</D:getlastmodified>
<D:resourcetype/>
<D:supportedlock>
<D:lockentry>
<D:lockscope><D:exclusive/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
<D:lockentry>
<D:lockscope><D:shared/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
</D:supportedlock>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
In this example, PROPFIND was invoked on the resource 9.1.4. Example - Using 'propname' to Retrieve All Property Names
http://www.foo.bar/container/ with a Depth header of 1, meaning the
request applies to the resource and its children, and a propfind XML
element containing the allprop XML element, meaning the request
should return the name and value of all properties defined on each
resource.
The resource http://www.foo.bar/container/ has six properties defined >>Request
on it:
http://www.foo.bar/boxschema/bigbox, PROPFIND /container/ HTTP/1.1
http://www.foo.bar/boxschema/author, DAV:creationdate, DAV: Host: www.example.com
displayname, DAV:resourcetype, and DAV:supportedlock. Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx
The last four properties are WebDAV-specific, defined in Section 13. <?xml version="1.0" encoding="utf-8" ?>
Since GET is not supported on this resource, the get* properties <propfind xmlns="DAV:">
(e.g., getcontentlength) are not defined on this resource. The DAV- <propname/>
specific properties assert that "container" was created on December </propfind>
1, 1997, at 5:42:21PM, in a time zone 8 hours west of GMT
(creationdate), has a name of "Example collection" (displayname), a
collection resource type (resourcetype), and supports exclusive write
and shared write locks (supportedlock).
The resource http://www.foo.bar/container/front.html has nine >>Response
properties defined on it:
http://www.foo.bar/boxschema/bigbox (another instance of the "bigbox" HTTP/1.1 207 Multi-Status
property type), DAV:creationdate, DAV:displayname, DAV: Content-Type: application/xml; charset="utf-8"
getcontentlength, DAV:getcontenttype, DAV:getetag, DAV: Content-Length: xxxx
getlastmodified, DAV:resourcetype, and DAV:supportedlock.
The DAV-specific properties assert that "front.html" was created on <?xml version="1.0" encoding="utf-8" ?>
December 1, 1997, at 6:27:21PM, in a time zone 8 hours west of GMT <multistatus xmlns="DAV:">
(creationdate), has a name of "Example HTML resource" (displayname), <response>
a content length of 4525 bytes (getcontentlength), a MIME type of <href>http://www.example.com/container/</href>
"text/html" (getcontenttype), an entity tag of "zzyzx" (getetag), was <propstat>
last modified on Monday, January 12, 1998, at 09:25:56 GMT <prop xmlns:R="http://ns.example.com/boxschema/">
(getlastmodified), has an empty resource type, meaning that it is not <R:bigbox/>
a collection (resourcetype), and supports both exclusive write and <R:author/>
shared write locks (supportedlock). <creationdate/>
<displayname/>
<resourcetype/>
<supportedlock/>
</prop>
<status>HTTP/1.1 200 OK</status>
</propstat>
</response>
<response>
<href>http://www.example.com/container/front.html</href>
<propstat>
<prop xmlns:R="http://ns.example.com/boxschema/">
<R:bigbox/>
<creationdate/>
<displayname/>
<getcontentlength/>
<getcontenttype/>
<getetag/>
<getlastmodified/>
<resourcetype/>
<supportedlock/>
</prop>
<status>HTTP/1.1 200 OK</status>
</propstat>
</response>
</multistatus>
8.1.3. Example - Using propname to Retrieve all Property Names In this example, PROPFIND is invoked on the collection resource
http://www.example.com/container/, with a propfind XML element
containing the propname XML element, meaning the name of all
properties should be returned. Since no Depth header is present, it
assumes its default value of "infinity", meaning the name of the
properties on the collection and all its descendents should be
returned.
Consistent with the previous example, resource
http://www.example.com/container/ has six properties defined on it:
bigbox and author in the "http://ns.example.com/boxschema/"
namespace, and creationdate, displayname, resourcetype, and
supportedlock in the "DAV:" namespace.
The resource http://www.example.com/container/index.html, a member of
the "container" collection, has nine properties defined on it, bigbox
in the "http://ns.example.com/boxschema/" namespace and,
creationdate, displayname, getcontentlength, getcontenttype, getetag,
getlastmodified, resourcetype, and supportedlock in the "DAV:"
namespace.
This example also demonstrates the use of XML namespace scoping and
the default namespace. Since the "xmlns" attribute does not contain
a prefix, the namespace applies by default to all enclosed elements.
Hence, all elements which do not explicitly state the namespace to
which they belong are members of the "DAV:" namespace.
9.1.5. Example - Using So-called 'allprop'
Note that 'allprop', despite its name which remains for backward-
compatibility, does not return every property, but only dead
properties and the live properties defined in this specification.
>>Request >>Request
PROPFIND /container/ HTTP/1.1 PROPFIND /container/ HTTP/1.1
Host: www.foo.bar Host: www.example.com
Content-Type: text/xml; charset="utf-8" Depth: 1
Content-Length: xxxx Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<propfind xmlns="DAV:"> <D:propfind xmlns:D="DAV:">
<propname/> <D:allprop/>
</propfind> </D:propfind>
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:">
<D:response>
<D:href>/container/</D:href>
<D:propstat>
<D:prop xmlns:R="http://ns.example.com/boxschema/">
<R:bigbox><R:BoxType>Box type A</R:BoxType></R:bigbox>
<R:author><R:Name>Hadrian</R:Name></R:author>
<D:creationdate>1997-12-01T17:42:21-08:00</D:creationdate>
<D:displayname>Example collection</D:displayname>
<D:resourcetype><D:collection/></D:resourcetype>
<D:supportedlock>
<D:lockentry>
<D:lockscope><D:exclusive/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
<D:lockentry>
<D:lockscope><D:shared/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
</D:supportedlock>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
<D:response>
<D:href>/container/front.html</D:href>
<D:propstat>
<D:prop xmlns:R="http://ns.example.com/boxschema/">
<R:bigbox><R:BoxType>Box type B</R:BoxType>
</R:bigbox>
<D:creationdate>1997-12-01T18:27:21-08:00</D:creationdate>
<D:displayname>Example HTML resource</D:displayname>
<D:getcontentlength>4525</D:getcontentlength>
<D:getcontenttype>text/html</D:getcontenttype>
<D:getetag>"zzyzx"</D:getetag>
<D:getlastmodified
>Mon, 12 Jan 1998 09:25:56 GMT</D:getlastmodified>
<D:resourcetype/>
<D:supportedlock>
<D:lockentry>
<D:lockscope><D:exclusive/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
<D:lockentry>
<D:lockscope><D:shared/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
<?xml version="1.0" encoding="utf-8" ?> </D:supportedlock>
<multistatus xmlns="DAV:"> </D:prop>
<response> <D:status>HTTP/1.1 200 OK</D:status>
<href>http://www.foo.bar/container/</href> </D:propstat>
<propstat> </D:response>
<prop xmlns:R="http://www.foo.bar/boxschema/"> </D:multistatus>
<R:bigbox/>
<R:author/>
<creationdate/>
<displayname/>
<resourcetype/>
<supportedlock/>
</prop>
<status>HTTP/1.1 200 OK</status>
</propstat>
</response>
<response>
<href>http://www.foo.bar/container/front.html</href>
<propstat>
<prop xmlns:R="http://www.foo.bar/boxschema/">
<R:bigbox/>
<creationdate/>
<displayname/>
<getcontentlength/>
<getcontenttype/>
<getetag/>
<getlastmodified/>
<resourcetype/>
<supportedlock/>
</prop>
<status>HTTP/1.1 200 OK</status>
</propstat>
</response>
</multistatus>
In this example, PROPFIND is invoked on the collection resource In this example, PROPFIND was invoked on the resource
http://www.foo.bar/container/, with a propfind XML element containing http://www.example.com/container/ with a Depth header of 1, meaning
the propname XML element, meaning the name of all properties should the request applies to the resource and its children, and a propfind
be returned. Since no Depth header is present, it assumes its XML element containing the allprop XML element, meaning the request
default value of "infinity", meaning the name of the properties on should return the name and value of all the dead properties defined
the collection and all its progeny should be returned. on the resources, plus the name and value of all the properties
defined in this specification. This example illustrates the use of
relative references in the 'href' elements of the response.
Consistent with the previous example, resource The resource http://www.example.com/container/ has six properties
http://www.foo.bar/container/ has six properties defined on it, defined on it: 'bigbox' and 'author in the
http://www.foo.bar/boxschema/bigbox, "http://ns.example.com/boxschema/" namespace, DAV:creationdate, DAV:
http://www.foo.bar/boxschema/author, DAV:creationdate, DAV:
displayname, DAV:resourcetype, and DAV:supportedlock. displayname, DAV:resourcetype, and DAV:supportedlock.
The resource http://www.foo.bar/container/index.html, a member of the The last four properties are WebDAV-specific, defined in Section 15.
"container" collection, has nine properties defined on it, Since GET is not supported on this resource, the get* properties
http://www.foo.bar/boxschema/bigbox, DAV:creationdate, DAV: (e.g., DAV:getcontentlength) are not defined on this resource. The
WebDAV-specific properties assert that "container" was created on
December 1, 1997, at 5:42:21PM, in a time zone 8 hours west of GMT
(DAV:creationdate), has a name of "Example collection" (DAV:
displayname), a collection resource type (DAV:resourcetype), and
supports exclusive write and shared write locks (DAV:supportedlock).
The resource http://www.example.com/container/front.html has nine
properties defined on it:
'bigbox' in the "http://ns.example.com/boxschema/" namespace (another
instance of the "bigbox" property type), DAV:creationdate, DAV:
displayname, DAV:getcontentlength, DAV:getcontenttype, DAV:getetag, displayname, DAV:getcontentlength, DAV:getcontenttype, DAV:getetag,
DAV:getlastmodified, DAV:resourcetype, and DAV:supportedlock. DAV:getlastmodified, DAV:resourcetype, and DAV:supportedlock.
This example also demonstrates the use of XML namespace scoping, and The DAV-specific properties assert that "front.html" was created on
the default namespace. Since the "xmlns" attribute does not contain December 1, 1997, at 6:27:21PM, in a time zone 8 hours west of GMT
an explicit "shorthand name" (prefix) letter, the namespace applies (DAV:creationdate), has a name of "Example HTML resource" (DAV:
by default to all enclosed elements. Hence, all elements which do displayname), a content length of 4525 bytes (DAV:getcontentlength),
not explicitly state the namespace to which they belong are members a MIME type of "text/html" (DAV:getcontenttype), an entity tag of
of the "DAV:" namespace schema. "zzyzx" (DAV:getetag), was last modified on Monday, January 12, 1998,
at 09:25:56 GMT (DAV:getlastmodified), has an empty resource type,
meaning that it is not a collection (DAV:resourcetype), and supports
both exclusive write and shared write locks (DAV:supportedlock).
8.2. PROPPATCH 9.1.6. Example - Using 'allprop' with 'include'
>>Request
PROPFIND /mycol/ HTTP/1.1
Host: www.example.com
Depth: 1
Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<D:propfind xmlns:D="DAV:">
<D:allprop/>
<D:include>
<D:supported-live-property-set/>
<D:supported-report-set/>
</D:include>
</D:propfind>
In this example, PROPFIND is executed on the resource
http://www.example.com/mycol/ and its internal member resources. The
client requests the values of all live properties defined in this
specification, plus all dead properties, plus two more live
properties defined in [RFC3253]. The response is not shown.
9.2. PROPPATCH Method
The PROPPATCH method processes instructions specified in the request The PROPPATCH method processes instructions specified in the request
body to set and/or remove properties defined on the resource body to set and/or remove properties defined on the resource
identified by the Request-URI. identified by the Request-URI.
All DAV compliant resources MUST support the PROPPATCH method and All DAV compliant resources MUST support the PROPPATCH method and
MUST process instructions that are specified using the MUST process instructions that are specified using the
propertyupdate, set, and remove XML elements of the DAV schema. propertyupdate, set, and remove XML elements. Execution of the
Execution of the directives in this method is, of course, subject to directives in this method is, of course, subject to access control
access control constraints. DAV compliant resources SHOULD support constraints. DAV compliant resources SHOULD support the setting of
the setting of arbitrary dead properties. arbitrary dead properties.
The request message body of a PROPPATCH method MUST contain the The request message body of a PROPPATCH method MUST contain the
propertyupdate XML element. Instruction processing MUST occur in the propertyupdate XML element.
order instructions are received (i.e., from top to bottom).
Servers MUST process PROPPATCH instructions in document order (an
exception to the normal rule that ordering is irrelevant).
Instructions MUST either all be executed or none executed. Thus if Instructions MUST either all be executed or none executed. Thus if
any error occurs during processing all executed instructions MUST be any error occurs during processing all executed instructions MUST be
undone and a proper error result returned. Instruction processing undone and a proper error result returned. Instruction processing
details can be found in the definition of the set and remove details can be found in the definition of the set and remove
instructions in Section 12.13. instructions in Section 14.23 and Section 14.26.
8.2.1. Status Codes for use with 207 (Multi-Status) If a server attempts to make any of the property changes in a
PROPPATCH request (i.e. the request is not rejected for high-level
errors before processing the body), the response MUST be a Multi-
Status response as described in Section 9.2.1.
The following are examples of response codes one would expect to be This method is idempotent, but not safe (see Section 9.1 of
used in a 207 (Multi-Status) response for this method. Note, [RFC2616]). Responses to this method MUST NOT be cached.
however, that unless explicitly prohibited any 2/3/4/5xx series
response code may be used in a 207 (Multi-Status) response.
200 (OK) - The command succeeded. As there can be a mixture of sets 9.2.1. Status Codes for Use in 'propstat' Element
and removes in a body, a 201 (Created) seems inappropriate.
In PROPPATCH responses, information about individual properties is
returned inside 'propstat' elements (see Section 14.22), each
containing an individual 'status' element containing information
about the properties appearing in it. The list below summarizes the
most common status codes used inside 'propstat', however clients
should be prepared to handle other 2/3/4/5xx series status codes as
well.
200 (OK) - The property set or change succeeded. Note that if this
appears for one property, it appears for every property in the
response, due to the atomicity of PROPPATCH.
403 (Forbidden) - The client, for reasons the server chooses not to 403 (Forbidden) - The client, for reasons the server chooses not to
specify, cannot alter one of the properties. specify, cannot alter one of the properties.
403 (Forbidden): The client has attempted to set a protected
property, such as DAV:getetag. If returning this error, the server
SHOULD use the precondition code 'cannot-modify-protected-property'
inside the response body.
409 (Conflict) - The client has provided a value whose semantics are 409 (Conflict) - The client has provided a value whose semantics are
not appropriate for the property. This includes trying to set read- not appropriate for the property.
only properties.
423 (Locked) - The specified resource is locked and the client either 424 (Failed Dependency) - The property change could not be made
is not a lock owner or the lock type requires a lock token to be because of another property change that failed.
submitted and the client did not submit it.
507 (Insufficient Storage) - The server did not have sufficient space 507 (Insufficient Storage) - The server did not have sufficient space
to record the property. to record the property.
8.2.2. Example - PROPPATCH 9.2.2. Example - PROPPATCH
>>Request >>Request
PROPPATCH /bar.html HTTP/1.1 PROPPATCH /bar.html HTTP/1.1
Host: www.foo.com Host: www.example.com
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:propertyupdate xmlns:D="DAV:" <D:propertyupdate xmlns:D="DAV:"
xmlns:Z="http://www.w3.com/standards/z39.50/"> xmlns:Z="http://ns.example.com/standards/z39.50/">
<D:set> <D:set>
<D:prop> <D:prop>
<Z:authors> <Z:Authors>
<Z:Author>Jim Whitehead</Z:Author> <Z:Author>Jim Whitehead</Z:Author>
<Z:Author>Roy Fielding</Z:Author> <Z:Author>Roy Fielding</Z:Author>
</Z:authors> </Z:Authors>
</D:prop> </D:prop>
</D:set> </D:set>
<D:remove> <D:remove>
<D:prop><Z:Copyright-Owner/></D:prop> <D:prop><Z:Copyright-Owner/></D:prop>
</D:remove> </D:remove>
</D:propertyupdate> </D:propertyupdate>
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:" <D:multistatus xmlns:D="DAV:"
xmlns:Z="http://www.w3.com/standards/z39.50"> xmlns:Z="http://ns.example.com/standards/z39.50/">
<D:response> <D:response>
<D:href>http://www.foo.com/bar.html</D:href> <D:href>http://www.example.com/bar.html</D:href>
<D:propstat> <D:propstat>
<D:prop><Z:Authors/></D:prop> <D:prop><Z:Authors/></D:prop>
<D:status>HTTP/1.1 424 Failed Dependency</D:status> <D:status>HTTP/1.1 424 Failed Dependency</D:status>
</D:propstat> </D:propstat>
<D:propstat> <D:propstat>
<D:prop><Z:Copyright-Owner/></D:prop> <D:prop><Z:Copyright-Owner/></D:prop>
<D:status>HTTP/1.1 409 Conflict</D:status> <D:status>HTTP/1.1 409 Conflict</D:status>
</D:propstat> </D:propstat>
<D:responsedescription> Copyright Owner can not be deleted or <D:responsedescription> Copyright Owner can not be deleted or
altered.</D:responsedescription> altered.</D:responsedescription>
</D:response> </D:response>
</D:multistatus> </D:multistatus>
In this example, the client requests the server to set the value of In this example, the client requests the server to set the value of
the http://www.w3.com/standards/z39.50/Authors property, and to the "Authors" property in the
remove the property "http://ns.example.com/standards/z39.50/" namespace, and to remove
http://www.w3.com/standards/z39.50/Copyright-Owner. Since the the property "Copyright-Owner" in the same namespace. Since the
Copyright-Owner property could not be removed, no property Copyright-Owner property could not be removed, no property
modifications occur. The 424 (Failed Dependency) status code for the modifications occur. The 424 (Failed Dependency) status code for the
Authors property indicates this action would have succeeded if it Authors property indicates this action would have succeeded if it
were not for the conflict with removing the Copyright-Owner property. were not for the conflict with removing the Copyright-Owner property.
8.3. MKCOL Method 9.3. MKCOL Method
The MKCOL method is used to create a new collection. All DAV
compliant resources MUST support the MKCOL method.
8.3.1. Request
MKCOL creates a new collection resource at the location specified by MKCOL creates a new collection resource at the location specified by
the Request-URI. If the resource identified by the Request-URI is the Request-URI. If the Request-URI is already mapped to a resource
non-null then the MKCOL MUST fail. During MKCOL processing, a server then the MKCOL MUST fail. During MKCOL processing, a server MUST
MUST make the Request-URI a member of its parent collection, unless make the Request-URI an internal member of its parent collection,
the Request-URI is "/". If no such ancestor exists, the method MUST unless the Request-URI is "/". If no such ancestor exists, the
fail. When the MKCOL operation creates a new collection resource, method MUST fail. When the MKCOL operation creates a new collection
all ancestors MUST already exist, or the method MUST fail with a 409 resource, all ancestors MUST already exist, or the method MUST fail
(Conflict) status code. For example, if a request to create with a 409 (Conflict) status code. For example, if a request to
collection /a/b/c/d/ is made, and neither /a/b/ nor /a/b/c/ exists, create collection /a/b/c/d/ is made, and /a/b/c/ does not exist, the
the request must fail. request must fail.
When MKCOL is invoked without a request body, the newly created When MKCOL is invoked without a request body, the newly created
collection SHOULD have no members. collection SHOULD have no members.
A MKCOL request message may contain a message body. The behavior of A MKCOL request message may contain a message body. The precise
a MKCOL request when the body is present is limited to creating behavior of a MKCOL request when the body is present is undefined,
collections, members of a collection, bodies of members and but limited to creating collections, members of a collection, bodies
properties on the collections or members. If the server receives a of members and properties on the collections or members. If the
MKCOL request entity type it does not support or understand it MUST server receives a MKCOL request entity type it does not support or
respond with a 415 (Unsupported Media Type) status code. The exact understand it MUST respond with a 415 (Unsupported Media Type) status
behavior of MKCOL for various request media types is undefined in code. If the server decides to reject the request based on the
this document, and will be specified in separate documents. presence of an entity or the type of an entity, it should use the 415
(Unsupported Media Type) status code.
8.3.2. Status Codes This method is idempotent, but not safe (see Section 9.1 of
[RFC2616]). Responses to this method MUST NOT be cached.
Responses from a MKCOL request MUST NOT be cached as MKCOL has non- 9.3.1. MKCOL Status Codes
idempotent semantics.
201 (Created) - The collection or structured resource was created in In addition to the general status codes possible, the following
its entirety. status codes have specific applicability to MKCOL:
201 (Created) - The collection was created.
403 (Forbidden) - This indicates at least one of two conditions: 1) 403 (Forbidden) - This indicates at least one of two conditions: 1)
the server does not allow the creation of collections at the given the server does not allow the creation of collections at the given
location in its namespace, or 2) the parent collection of the location in its URL namespace, or 2) the parent collection of the
Request-URI exists but cannot accept members. Request-URI exists but cannot accept members.
405 (Method Not Allowed) - MKCOL can only be executed on a deleted/ 405 (Method Not Allowed) - MKCOL can only be executed on an unmapped
non-existent resource. URL.
409 (Conflict) - A collection cannot be made at the Request-URI until 409 (Conflict) - A collection cannot be made at the Request-URI until
one or more intermediate collections have been created. one or more intermediate collections have been created. The server
MUST NOT create those intermediate collections automatically.
415 (Unsupported Media Type)- The server does not support the request 415 (Unsupported Media Type) - The server does not support the
type of the body. request body type (although bodies are legal on MKCOL requests, since
this specification doesn't define any, the server is likely not to
support any given body type).
507 (Insufficient Storage) - The resource does not have sufficient 507 (Insufficient Storage) - The resource does not have sufficient
space to record the state of the resource after the execution of this space to record the state of the resource after the execution of this
method. method.
8.3.3. Example - MKCOL 9.3.2. Example - MKCOL
This example creates a collection called /webdisc/xfiles/ on the This example creates a collection called /webdisc/xfiles/ on the
server www.server.org. server www.example.com.
>>Request >>Request
MKCOL /webdisc/xfiles/ HTTP/1.1 MKCOL /webdisc/xfiles/ HTTP/1.1
Host: www.server.org Host: www.example.com
>>Response >>Response
HTTP/1.1 201 Created HTTP/1.1 201 Created
8.4. GET, HEAD for Collections 9.4. GET, HEAD for Collections
The semantics of GET are unchanged when applied to a collection, The semantics of GET are unchanged when applied to a collection,
since GET is defined as, "retrieve whatever information (in the form since GET is defined as, "retrieve whatever information (in the form
of an entity) is identified by the Request-URI" [RFC2068]. GET when of an entity) is identified by the Request-URI" [RFC2616]. GET when
applied to a collection may return the contents of an "index.html" applied to a collection may return the contents of an "index.html"
resource, a human-readable view of the contents of the collection, or resource, a human-readable view of the contents of the collection, or
something else altogether. Hence it is possible that the result of a something else altogether. Hence it is possible that the result of a
GET on a collection will bear no correlation to the membership of the GET on a collection will bear no correlation to the membership of the
collection. collection.
Similarly, since the definition of HEAD is a GET without a response Similarly, since the definition of HEAD is a GET without a response
message body, the semantics of HEAD are unmodified when applied to message body, the semantics of HEAD are unmodified when applied to
collection resources. collection resources.
8.5. POST for Collections 9.5. POST for Collections
Since by definition the actual function performed by POST is Since by definition the actual function performed by POST is
determined by the server and often depends on the particular determined by the server and often depends on the particular
resource, the behavior of POST when applied to collections cannot be resource, the behavior of POST when applied to collections cannot be
meaningfully modified because it is largely undefined. Thus the meaningfully modified because it is largely undefined. Thus the
semantics of POST are unmodified when applied to a collection. semantics of POST are unmodified when applied to a collection.
8.6. DELETE 9.6. DELETE Requirements
8.6.1. DELETE for Non-Collection Resources DELETE is defined in [RFC2616], Section 9.7, to "delete the resource
identified by the Request-URI". However, WebDAV changes some DELETE
handling requirements.
If the DELETE method is issued to a non-collection resource whose A server processing a successful DELETE request:
URIs are an internal member of one or more collections, then during
DELETE processing a server MUST remove any URI for the resource
identified by the Request-URI from collections which contain it as a
member.
8.6.2. DELETE for Collections MUST destroy locks rooted on the deleted resource
MUST remove the mapping from the Request-URI to any resource.
Thus, after a successful DELETE operation (and in the absence of
other actions) a subsequent GET/HEAD/PROPFIND request to the target
Request-URI MUST return 404 (Not Found).
9.6.1. DELETE for Collections
The DELETE method on a collection MUST act as if a "Depth: infinity" The DELETE method on a collection MUST act as if a "Depth: infinity"
header was used on it. A client MUST NOT submit a Depth header with header was used on it. A client MUST NOT submit a Depth header with
a DELETE on a collection with any value but infinity. a DELETE on a collection with any value but infinity.
DELETE instructs that the collection specified in the Request-URI and DELETE instructs that the collection specified in the Request-URI and
all resources identified by its internal member URIs are to be all resources identified by its internal member URLs are to be
deleted. deleted.
If any resource identified by a member URI cannot be deleted then all If any resource identified by a member URL cannot be deleted then all
of the member's ancestors MUST NOT be deleted, so as to maintain of the member's ancestors MUST NOT be deleted, so as to maintain URL
namespace consistency. namespace consistency.
Any headers included with DELETE MUST be applied in processing every Any headers included with DELETE MUST be applied in processing every
resource to be deleted. resource to be deleted.
When the DELETE method has completed processing it MUST result in a When the DELETE method has completed processing it MUST result in a
consistent namespace. consistent URL namespace.
If an error occurs with a resource other than the resource identified If an error occurs deleting a member resource (a resource other than
in the Request-URI then the response MUST be a 207 (Multi-Status). the resource identified in the Request-URI) then the response can be
424 (Failed Dependency) errors SHOULD NOT be in the 207 (Multi- a 207 (Multi-Status). Multi-Status is used here to indicate which
Status). They can be safely left out because the client will know internal resources could NOT be deleted, including an error code
that the ancestors of a resource could not be deleted when the client which should help the client understand which resources caused the
receives an error for the ancestor's progeny. Additionally 204 (No failure. For example, the Multi-Status body could include a response
Content) errors SHOULD NOT be returned in the 207 (Multi-Status). with status 423 (Locked) if an internal resource was locked.
The reason for this prohibition is that 204 (No Content) is the
default success code.
8.6.2.1. Example - DELETE The server MAY return a 4xx status response, rather than a 207, if
the request failed completely.
424 (Failed Dependency) status codes SHOULD NOT be in the 207 (Multi-
Status) response for DELETE. They can be safely left out because the
client will know that the ancestors of a resource could not be
deleted when the client receives an error for the ancestor's progeny.
Additionally 204 (No Content) errors SHOULD NOT be returned in the
207 (Multi-Status). The reason for this prohibition is that 204 (No
Content) is the default success code.
9.6.2. Example - DELETE
>>Request >>Request
DELETE /container/ HTTP/1.1 DELETE /container/ HTTP/1.1
Host: www.foo.bar Host: www.example.com
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<d:multistatus xmlns:d="DAV:"> <d:multistatus xmlns:d="DAV:">
<d:response> <d:response>
<d:href>http://www.foo.bar/container/resource3</d:href> <d:href>http://www.example.com/container/resource3</d:href>
<d:status>HTTP/1.1 423 Locked</d:status> <d:status>HTTP/1.1 423 Locked</d:status>
</d:response> <d:error><d:lock-token-submitted/></d:error>
</d:multistatus> </d:response>
</d:multistatus>
In this example the attempt to delete In this example the attempt to delete
http://www.foo.bar/container/resource3 failed because it is locked, http://www.example.com/container/resource3 failed because it is
and no lock token was submitted with the request. Consequently, the locked, and no lock token was submitted with the request.
attempt to delete http://www.foo.bar/container/ also failed. Thus Consequently, the attempt to delete http://www.example.com/container/
the client knows that the attempt to delete also failed. Thus the client knows that the attempt to delete
http://www.foo.bar/container/ must have also failed since the parent http://www.example.com/container/ must have also failed since the
can not be deleted unless its child has also been deleted. Even parent can not be deleted unless its child has also been deleted.
though a Depth header has not been included, a depth of infinity is Even though a Depth header has not been included, a depth of infinity
assumed because the method is on a collection. is assumed because the method is on a collection.
8.7. PUT 9.7. PUT Requirements
8.7.1. PUT for Non-Collection Resources 9.7.1. PUT for Non-Collection Resources
A PUT performed on an existing resource replaces the GET response A PUT performed on an existing resource replaces the GET response
entity of the resource. Properties defined on the resource may be entity of the resource. Properties defined on the resource may be
recomputed during PUT processing but are not otherwise affected. For recomputed during PUT processing but are not otherwise affected. For
example, if a server recognizes the content type of the request body, example, if a server recognizes the content type of the request body,
it may be able to automatically extract information that could be it may be able to automatically extract information that could be
profitably exposed as properties. profitably exposed as properties.
A PUT that would result in the creation of a resource without an A PUT that would result in the creation of a resource without an
appropriately scoped parent collection MUST fail with a 409 appropriately scoped parent collection MUST fail with a 409
(Conflict). (Conflict).
8.7.2. PUT for Collections A PUT request allows a client to indicate what media type an entity
body has, and whether it should change if overwritten. Thus, a
client SHOULD provide a Content-Type for a new resource if any is
known. If the client does not provide a Content-Type for a new
resource, the server MAY create a resource with no Content-Type
assigned, or it MAY attempt to assign a Content-Type.
As defined in the HTTP/1.1 specification [RFC2068], the "PUT method Note that although a recipient ought generally to treat metadata
requests that the enclosed entity be stored under the supplied supplied with an HTTP request as authoritative, in practice there's
Request-URI." Since submission of an entity representing a no guarantee that a server will accept client-supplied metadata (e.g.
collection would implicitly encode creation and deletion of any request header beginning with "Content-"). Many servers do not
resources, this specification intentionally does not define a allow configuring the Content-Type on a per-resource basis in the
transmission format for creating a collection using PUT. Instead, first place. Thus, clients can't always rely on the ability to
the MKCOL method is defined to create collections. directly influence the content type by including a Content-Type
request header.
When the PUT operation creates a new non-collection resource all 9.7.2. PUT for Collections
ancestors MUST already exist. If all ancestors do not exist, the
method MUST fail with a 409 (Conflict) status code. For example, if
resource /a/b/c/d.html is to be created and /a/b/c/ does not exist,
then the request must fail.
8.8. COPY Method This specification does not define the behavior of the PUT method for
existing collections. A PUT request to an existing collection MAY be
treated as an error (405 Method Not Allowed).
The COPY method creates a duplicate of the source resource, The MKCOL method is defined to create collections.
identified by the Request-URI, in the destination resource,
identified by the URI in the Destination header. The Destination 9.8. COPY Method
header MUST be present. The exact behavior of the COPY method
depends on the type of the source resource. The COPY method creates a duplicate of the source resource identified
by the Request-URI, in the destination resource identified by the URI
in the Destination header. The Destination header MUST be present.
The exact behavior of the COPY method depends on the type of the
source resource.
All WebDAV compliant resources MUST support the COPY method. All WebDAV compliant resources MUST support the COPY method.
However, support for the COPY method does not guarantee the ability However, support for the COPY method does not guarantee the ability
to copy a resource. For example, separate programs may control to copy a resource. For example, separate programs may control
resources on the same server. As a result, it may not be possible to resources on the same server. As a result, it may not be possible to
copy a resource to a location that appears to be on the same server. copy a resource to a location that appears to be on the same server.
8.8.1. COPY for HTTP/1.1 resources This method is idempotent, but not safe (see Section 9.1 of
[RFC2616]). Responses to this method MUST NOT be cached.
9.8.1. COPY for Non-collection Resources
When the source resource is not a collection the result of the COPY When the source resource is not a collection the result of the COPY
method is the creation of a new resource at the destination whose method is the creation of a new resource at the destination whose
state and behavior match that of the source resource as closely as state and behavior match that of the source resource as closely as
possible. After a successful COPY invocation, all properties on the possible. Since the environment at the destination may be different
source resource MUST be duplicated on the destination resource, than at the source due to factors outside the scope of control of the
subject to modifying headers and XML elements, following the server, such as the absence of resources required for correct
definition for copying properties. Since the environment at the operation, it may not be possible to completely duplicate the
destination may be different than at the source due to factors behavior of the resource at the destination. Subsequent alterations
outside the scope of control of the server, such as the absence of to the destination resource will not modify the source resource.
resources required for correct operation, it may not be possible to Subsequent alterations to the source resource will not modify the
completely duplicate the behavior of the resource at the destination. destination resource.
Subsequent alterations to the destination resource will not modify
the source resource. Subsequent alterations to the source resource
will not modify the destination resource.
8.8.2. COPY for Properties
The following section defines how properties on a resource are 9.8.2. COPY for Properties
handled during a COPY operation.
Live properties SHOULD be duplicated as identically behaving live After a successful COPY invocation, all dead properties on the source
properties at the destination resource. If a property cannot be resource SHOULD be duplicated on the destination resource. Live
copied live, then its value MUST be duplicated, octet-for-octet, in properties described in this document SHOULD be duplicated as
an identically named, dead property on the destination resource identically behaving live properties at the destination resource, but
subject to the effects of the propertybehavior XML element. not necessarily with the same values. Servers SHOULD NOT convert
live properties into dead properties on the destination resource,
because clients may then draw incorrect conclusions about the state
or functionality of a resource. Note that some live properties are
defined such that the absence of the property has a specific meaning
(e.g. a flag with one meaning if present and the opposite if absent),
and in these cases, a successful COPY might result in the property
being reported as "Not Found" in subsequent requests.
The propertybehavior XML element can specify that properties are When the destination is an unmapped URL, a COPY operation creates a
copied on best effort, that all live properties must be successfully new resource much like a PUT operation does. Live properties which
copied or the method must fail, or that a specified list of live are related to resource creation (such as DAV:creationdate) should
properties must be successfully copied or the method must fail. The have their values set accordingly.
propertybehavior XML element is defined in Section 12.12.
8.8.3. COPY for Collections 9.8.3. COPY for Collections
The COPY method on a collection without a Depth header MUST act as if The COPY method on a collection without a Depth header MUST act as if
a Depth header with value "infinity" was included. A client may a Depth header with value "infinity" was included. A client may
submit a Depth header on a COPY on a collection with a value of "0" submit a Depth header on a COPY on a collection with a value of "0"
or "infinity". DAV compliant servers MUST support the "0" and or "infinity". Servers MUST support the "0" and "infinity" Depth
"infinity" Depth header behaviors. header behaviors on WebDAV-compliant resources.
A COPY of depth infinity instructs that the collection resource An infinite depth COPY instructs that the collection resource
identified by the Request-URI is to be copied to the location identified by the Request-URI is to be copied to the location
identified by the URI in the Destination header, and all its internal identified by the URI in the Destination header, and all its internal
member resources are to be copied to a location relative to it, member resources are to be copied to a location relative to it,
recursively through all levels of the collection hierarchy. recursively through all levels of the collection hierarchy. Note
that an infinite depth COPY of /A/ into /A/B/ could lead to infinite
recursion if not handled correctly.
A COPY of "Depth: 0" only instructs that the collection and its A COPY of "Depth: 0" only instructs that the collection and its
properties but not resources identified by its internal member URIs, properties but not resources identified by its internal member URLs,
are to be copied. are to be copied.
Any headers included with a COPY MUST be applied in processing every Any headers included with a COPY MUST be applied in processing every
resource to be copied with the exception of the Destination header. resource to be copied with the exception of the Destination header.
The Destination header only specifies the destination URI for the The Destination header only specifies the destination URI for the
Request-URI. When applied to members of the collection identified by Request-URI. When applied to members of the collection identified by
the Request-URI the value of Destination is to be modified to reflect the Request-URI the value of Destination is to be modified to reflect
the current location in the hierarchy. So, if the Request- URI is the current location in the hierarchy. So, if the Request-URI is /a/
/a/ with Host header value http://fun.com/ and the Destination is with Host header value http://example.com/ and the Destination is
http://fun.com/b/ then when http://fun.com/a/c/d is processed it must http://example.com/b/ then when http://example.com/a/c/d is processed
use a Destination of http://fun.com/b/c/d. it must use a Destination of http://example.com/b/c/d.
When the COPY method has completed processing it MUST have created a When the COPY method has completed processing it MUST have created a
consistent namespace at the destination (see Section 5.1 for the consistent URL namespace at the destination (see Section 5.1 for the
definition of namespace consistency). However, if an error occurs definition of namespace consistency). However, if an error occurs
while copying an internal collection, the server MUST NOT copy any while copying an internal collection, the server MUST NOT copy any
resources identified by members of this collection (i.e., the server resources identified by members of this collection (i.e., the server
must skip this subtree), as this would create an inconsistent must skip this subtree), as this would create an inconsistent
namespace. After detecting an error, the COPY operation SHOULD try namespace. After detecting an error, the COPY operation SHOULD try
to finish as much of the original copy operation as possible (i.e., to finish as much of the original copy operation as possible (i.e.,
the server should still attempt to copy other subtrees and their the server should still attempt to copy other subtrees and their
members, that are not descendents of an error-causing collection). members, that are not descendents of an error-causing collection).
So, for example, if an infinite depth copy operation is performed on So, for example, if an infinite depth copy operation is performed on
collection /a/, which contains collections /a/b/ and /a/c/, and an collection /a/, which contains collections /a/b/ and /a/c/, and an
error occurs copying /a/b/, an attempt should still be made to copy error occurs copying /a/b/, an attempt should still be made to copy
/a/c/. Similarly, after encountering an error copying a non- /a/c/. Similarly, after encountering an error copying a non-
collection resource as part of an infinite depth copy, the server collection resource as part of an infinite depth copy, the server
SHOULD try to finish as much of the original copy operation as SHOULD try to finish as much of the original copy operation as
possible. possible.
If an error in executing the COPY method occurs with a resource other If an error in executing the COPY method occurs with a resource other
than the resource identified in the Request-URI then the response than the resource identified in the Request-URI then the response
skipping to change at page 41, line 43 skipping to change at page 59, line 37
So, for example, if an infinite depth copy operation is performed on So, for example, if an infinite depth copy operation is performed on
collection /a/, which contains collections /a/b/ and /a/c/, and an collection /a/, which contains collections /a/b/ and /a/c/, and an
error occurs copying /a/b/, an attempt should still be made to copy error occurs copying /a/b/, an attempt should still be made to copy
/a/c/. Similarly, after encountering an error copying a non- /a/c/. Similarly, after encountering an error copying a non-
collection resource as part of an infinite depth copy, the server collection resource as part of an infinite depth copy, the server
SHOULD try to finish as much of the original copy operation as SHOULD try to finish as much of the original copy operation as
possible. possible.
If an error in executing the COPY method occurs with a resource other If an error in executing the COPY method occurs with a resource other
than the resource identified in the Request-URI then the response than the resource identified in the Request-URI then the response
MUST be a 207 (Multi-Status). MUST be a 207 (Multi-Status), and the URL of the resource causing the
failure MUST appear with the specific error.
The 424 (Failed Dependency) status code SHOULD NOT be returned in the The 424 (Failed Dependency) status code SHOULD NOT be returned in the
207 (Multi-Status) response from a COPY method. These responses can 207 (Multi-Status) response from a COPY method. These responses can
be safely omitted because the client will know that the progeny of a be safely omitted because the client will know that the progeny of a
resource could not be copied when the client receives an error for resource could not be copied when the client receives an error for
the parent. Additionally 201 (Created)/204 (No Content) status codes the parent. Additionally 201 (Created)/204 (No Content) status codes
SHOULD NOT be returned as values in 207 (Multi-Status) responses from SHOULD NOT be returned as values in 207 (Multi-Status) responses from
COPY methods. They, too, can be safely omitted because they are the COPY methods. They, too, can be safely omitted because they are the
default success codes. default success codes.
8.8.4. COPY and the Overwrite Header 9.8.4. COPY and Overwriting Destination Resources
If a resource exists at the destination and the Overwrite header is If a COPY request has an Overwrite header with a value of "F", and a
"T" then prior to performing the copy the server MUST perform a resource exists at the Destination URL, the server MUST fail the
DELETE with "Depth: infinity" on the destination resource. If the request.
Overwrite header is set to "F" then the operation will fail.
8.8.5. Status Codes When a server executes a COPY request and overwrites a destination
resource, the exact behavior MAY depend on many factors, including
WebDAV extension capabilities (see particularly [RFC3253]). For
example, when an ordinary resource is overwritten, the server could
delete the target resource before doing the copy, or could do an in-
place overwrite to preserve live properties.
When a collection is overwritten, the membership of the destination
collection after the successful COPY request MUST be the same
membership as the source collection immediately before the COPY.
Thus, merging the membership of the source and destination
collections together in the destination is not a compliant behavior.
In general, if clients require the state of the destination URL to be
wiped out prior to a COPY (e.g. to force live properties to be
reset), then the client could send a DELETE to the destination before
the COPY request to ensure this reset.
9.8.5. Status Codes
In addition to the general status codes possible, the following
status codes have specific applicability to COPY:
201 (Created) - The source resource was successfully copied. The 201 (Created) - The source resource was successfully copied. The
copy operation resulted in the creation of a new resource. COPY operation resulted in the creation of a new resource.
204 (No Content) - The source resource was successfully copied to a 204 (No Content) - The source resource was successfully copied to a
pre-existing destination resource. pre-existing destination resource.
403 (Forbidden) - The source and destination URIs are the same. 207 (Multi-Status) - Multiple resources were to be affected by the
COPY, but errors on some of them prevented the operation from taking
place. Specific error messages, together with the most appropriate
of the source and destination URLs, appear in the body of the multi-
status response. E.g. if a destination resource was locked and could
not be overwritten, then the destination resource URL appears with
the 423 (Locked) status.
403 (Forbidden) - The operation is forbidden. A special case for
COPY could be that the source and destination resources are the same
resource.
409 (Conflict) - A resource cannot be created at the destination 409 (Conflict) - A resource cannot be created at the destination
until one or more intermediate collections have been created. until one or more intermediate collections have been created. The
server MUST NOT create those intermediate collections automatically.
412 (Precondition Failed) - The server was unable to maintain the 412 (Precondition Failed) - A precondition header check failed, e.g.
liveness of the properties listed in the propertybehavior XML element
or the Overwrite header is "F" and the state of the destination
resource is non-null.
423 (Locked) - The destination resource was locked. the Overwrite header is "F" and the destination URL is already mapped
to a resource.
423 (Locked) - The destination resource, or resource within the
destination collection, was locked. This response SHOULD contain the
'lock-token-submitted' precondition element.
502 (Bad Gateway) - This may occur when the destination is on another 502 (Bad Gateway) - This may occur when the destination is on another
server and the destination server refuses to accept the resource. server, repository or URL namespace. Either the source namespace
does not support copying to the destination namespace, or the
destination namespace refuses to accept the resource. The client may
wish to try GET/PUT and PROPFIND/PROPPATCH instead.
507 (Insufficient Storage) - The destination resource does not have 507 (Insufficient Storage) - The destination resource does not have
sufficient space to record the state of the resource after the sufficient space to record the state of the resource after the
execution of this method. execution of this method.
8.8.6. Example - COPY with Overwrite 9.8.6. Example - COPY with Overwrite
This example shows resource This example shows resource
http://www.ics.uci.edu/~fielding/index.html being copied to the http://www.example.com/~fielding/index.html being copied to the
location http://www.ics.uci.edu/users/f/fielding/index.html. The 204 location http://www.example.com/users/f/fielding/index.html. The 204
(No Content) status code indicates the existing resource at the (No Content) status code indicates the existing resource at the
destination was overwritten. destination was overwritten.
>>Request >>Request
COPY /~fielding/index.html HTTP/1.1 COPY /~fielding/index.html HTTP/1.1
Host: www.ics.uci.edu Host: www.example.com
Destination: http://www.ics.uci.edu/users/f/fielding/index.html Destination: http://www.example.com/users/f/fielding/index.html
>>Response >>Response
HTTP/1.1 204 No Content HTTP/1.1 204 No Content
8.8.7. Example - COPY with No Overwrite 9.8.7. Example - COPY with No Overwrite
The following example shows the same copy operation being performed, The following example shows the same copy operation being performed,
but with the Overwrite header set to "F." A response of 412 but with the Overwrite header set to "F." A response of 412
(Precondition Failed) is returned because the destination resource (Precondition Failed) is returned because the destination URL is
has a non-null state. already mapped to a resource.
>>Request >>Request
COPY /~fielding/index.html HTTP/1.1 COPY /~fielding/index.html HTTP/1.1
Host: www.ics.uci.edu Host: www.example.com
Destination: http://www.ics.uci.edu/users/f/fielding/index.html Destination: http://www.example.com/users/f/fielding/index.html
Overwrite: F Overwrite: F
>>Response >>Response
HTTP/1.1 412 Precondition Failed HTTP/1.1 412 Precondition Failed
8.8.8. Example - COPY of a Collection 9.8.8. Example - COPY of a Collection
>>Request >>Request
COPY /container/ HTTP/1.1 COPY /container/ HTTP/1.1
Host: www.foo.bar Host: www.example.com
Destination: http://www.foo.bar/othercontainer/ Destination: http://www.example.com/othercontainer/
Depth: infinity Depth: infinity
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<d:propertybehavior xmlns:d="DAV:">
<d:keepalive>*</d:keepalive>
</d:propertybehavior>
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<d:multistatus xmlns:d="DAV:">
<d:response> <d:multistatus xmlns:d="DAV:">
<d:href>http://www.foo.bar/othercontainer/R2/</d:href> <d:response>
<d:status>HTTP/1.1 412 Precondition Failed</d:status> <d:href>http://www.example.com/othercontainer/R2/</d:href>
</d:response> <d:status>HTTP/1.1 423 Locked</d:status>
</d:multistatus> <d:error><d:lock-token-submitted/></d:error>
</d:response>
</d:multistatus>
The Depth header is unnecessary as the default behavior of COPY on a The Depth header is unnecessary as the default behavior of COPY on a
collection is to act as if a "Depth: infinity" header had been collection is to act as if a "Depth: infinity" header had been
submitted. In this example most of the resources, along with the submitted. In this example most of the resources, along with the
collection, were copied successfully. However the collection R2 collection, were copied successfully. However the collection R2
failed, most likely due to a problem with maintaining the liveness of failed because the destination R2 is locked. Because there was an
properties (this is specified by the propertybehavior XML element). error copying R2, none of R2's members were copied. However no
Because there was an error copying R2, none of R2's members were errors were listed for those members due to the error minimization
copied. However no errors were listed for those members due to the rules.
error minimization rules given in Section 8.8.3.
8.9. MOVE Method 9.9. MOVE Method
The MOVE operation on a non-collection resource is the logical The MOVE operation on a non-collection resource is the logical
equivalent of a copy (COPY), followed by consistency maintenance equivalent of a copy (COPY), followed by consistency maintenance
processing, followed by a delete of the source, where all three processing, followed by a delete of the source, where all three
actions are performed atomically. The consistency maintenance step actions are performed in a single operation. The consistency
allows the server to perform updates caused by the move, such as maintenance step allows the server to perform updates caused by the
updating all URIs other than the Request-URI which identify the move, such as updating all URLs other than the Request-URI which
source resource, to point to the new destination resource. identify the source resource, to point to the new destination
Consequently, the Destination header MUST be present on all MOVE resource.
methods and MUST follow all COPY requirements for the COPY part of
the MOVE method. All DAV compliant resources MUST support the MOVE
method. However, support for the MOVE method does not guarantee the
ability to move a resource to a particular destination.
For example, separate programs may actually control different sets of The Destination header MUST be present on all MOVE methods and MUST
resources on the same server. Therefore, it may not be possible to follow all COPY requirements for the COPY part of the MOVE method.
move a resource within a namespace that appears to belong to the same All WebDAV compliant resources MUST support the MOVE method.
server.
Support for the MOVE method does not guarantee the ability to move a
resource to a particular destination. For example, separate programs
may actually control different sets of resources on the same server.
Therefore, it may not be possible to move a resource within a
namespace that appears to belong to the same server.
If a resource exists at the destination, the destination resource If a resource exists at the destination, the destination resource
will be DELETEd as a side-effect of the MOVE operation, subject to will be deleted as a side-effect of the MOVE operation, subject to
the restrictions of the Overwrite header. the restrictions of the Overwrite header.
8.9.1. MOVE for Properties This method is idempotent, but not safe (see Section 9.1 of
[RFC2616]). Responses to this method MUST NOT be cached.
The behavior of properties on a MOVE, including the effects of the 9.9.1. MOVE for Properties
propertybehavior XML element, MUST be the same as specified in
Section 8.8.2.
8.9.2. MOVE for Collections Live properties described in this document SHOULD be moved along with
the resource, such that the resource has identically behaving live
properties at the destination resource, but not necessarily with the
same values. Note that some live properties are defined such that
the absence of the property has a specific meaning (e.g. a flag with
one meaning if present and the opposite if absent), and in these
cases, a successful MOVE might result in the property being reported
as "Not Found" in subsequent requests. If the live properties will
not work the same way at the destination, the server MAY fail the
request.
MOVE is frequently used by clients to rename a file without changing
its parent collection, so it's not appropriate to reset all live
properties which are set at resource creation. For example, the DAV:
creationdate property value SHOULD remain the same after a MOVE.
Dead properties MUST be moved along with the resource.
9.9.2. MOVE for Collections
A MOVE with "Depth: infinity" instructs that the collection A MOVE with "Depth: infinity" instructs that the collection
identified by the Request-URI be moved to the URI specified in the identified by the Request-URI be moved to the address specified in
Destination header, and all resources identified by its internal the Destination header, and all resources identified by its internal
member URIs are to be moved to locations relative to it, recursively member URLs are to be moved to locations relative to it, recursively
through all levels of the collection hierarchy. through all levels of the collection hierarchy.
The MOVE method on a collection MUST act as if a "Depth: infinity" The MOVE method on a collection MUST act as if a "Depth: infinity"
header was used on it. A client MUST NOT submit a Depth header on a header was used on it. A client MUST NOT submit a Depth header on a
MOVE on a collection with any value but "infinity". MOVE on a collection with any value but "infinity".
Any headers included with MOVE MUST be applied in processing every Any headers included with MOVE MUST be applied in processing every
resource to be moved with the exception of the Destination header. resource to be moved with the exception of the Destination header.
The behavior of the Destination header is the same as given for COPY The behavior of the Destination header is the same as given for COPY
on collections. on collections.
When the MOVE method has completed processing it MUST have created a When the MOVE method has completed processing it MUST have created a
consistent namespace at both the source and destination (see section consistent URL namespace at both the source and destination (see
5.1 for the definition of namespace consistency). However, if an section 5.1 for the definition of namespace consistency). However,
error occurs while moving an internal collection, the server MUST NOT if an error occurs while moving an internal collection, the server
move any resources identified by members of the failed collection MUST NOT move any resources identified by members of the failed
(i.e., the server must skip the error-causing subtree), as this would collection (i.e., the server must skip the error-causing subtree), as
create an inconsistent namespace. In this case, after detecting the this would create an inconsistent namespace. In this case, after
error, the move operation SHOULD try to finish as much of the detecting the error, the move operation SHOULD try to finish as much
original move as possible (i.e., the server should still attempt to of the original move as possible (i.e., the server should still
move other subtrees and the resources identified by their members, attempt to move other subtrees and the resources identified by their
that are not descendents of an error-causing collection). So, for members, that are not descendents of an error-causing collection).
example, if an infinite depth move is performed on collection /a/, So, for example, if an infinite depth move is performed on collection
which contains collections /a/b/ and /a/c/, and an error occurs /a/, which contains collections /a/b/ and /a/c/, and an error occurs
moving /a/b/, an attempt should still be made to try moving /a/c/. moving /a/b/, an attempt should still be made to try moving /a/c/.
Similarly, after encountering an error moving a non-collection Similarly, after encountering an error moving a non-collection
resource as part of an infinite depth move, the server SHOULD try to resource as part of an infinite depth move, the server SHOULD try to
finish as much of the original move operation as possible. finish as much of the original move operation as possible.
If an error occurs with a resource other than the resource identified If an error occurs with a resource other than the resource identified
in the Request-URI then the response MUST be a 207 (Multi-Status). in the Request-URI then the response MUST be a 207 (Multi-Status),
and the errored resource's URL MUST appear with the specific error.
The 424 (Failed Dependency) status code SHOULD NOT be returned in the The 424 (Failed Dependency) status code SHOULD NOT be returned in the
207 (Multi-Status) response from a MOVE method. These errors can be 207 (Multi-Status) response from a MOVE method. These errors can be
safely omitted because the client will know that the progeny of a safely omitted because the client will know that the progeny of a
resource could not be moved when the client receives an error for the resource could not be moved when the client receives an error for the
parent. Additionally 201 (Created)/204 (No Content) responses SHOULD parent. Additionally 201 (Created)/204 (No Content) responses SHOULD
NOT be returned as values in 207 (Multi-Status) responses from a NOT be returned as values in 207 (Multi-Status) responses from a
MOVE. These responses can be safely omitted because they are the MOVE. These responses can be safely omitted because they are the
default success codes. default success codes.
8.9.3. MOVE and the Overwrite Header 9.9.3. MOVE and the Overwrite Header
If a resource exists at the destination and the Overwrite header is If a resource exists at the destination and the Overwrite header is
"T" then prior to performing the move the server MUST perform a "T" then prior to performing the move the server MUST perform a
DELETE with "Depth: infinity" on the destination resource. If the DELETE with "Depth: infinity" on the destination resource. If the
Overwrite header is set to "F" then the operation will fail. Overwrite header is set to "F" then the operation will fail.
8.9.4. Status Codes 9.9.4. Status Codes
In addition to the general status codes possible, the following
status codes have specific applicability to MOVE:
201 (Created) - The source resource was successfully moved, and a new 201 (Created) - The source resource was successfully moved, and a new
resource was created at the destination. URL mapping was created at the destination.
204 (No Content) - The source resource was successfully moved to a 204 (No Content) - The source resource was successfully moved to a
pre-existing destination resource. URL that was already mapped.
403 (Forbidden) - The source and destination URIs are the same. 207 (Multi-Status) - Multiple resources were to be affected by the
MOVE, but errors on some of them prevented the operation from taking
place. Specific error messages, together with the most appropriate
of the source and destination URLs, appear in the body of the multi-
status response. E.g. if a source resource was locked and could not
be moved, then the source resource URL appears with the 423 (Locked)
status.
403 (Forbidden) - Among many possible reasons for forbidding a MOVE
operation, this status code is recommended for use when the source
and destination resources are the same.
409 (Conflict) - A resource cannot be created at the destination 409 (Conflict) - A resource cannot be created at the destination
until one or more intermediate collections have been created. until one or more intermediate collections have been created. The
server MUST NOT create those intermediate collections automatically.
Or, the server was unable to preserve the behavior of the live
properties and still move the resource to the destination (see
'preserved-live-properties' postcondition).
412 (Precondition Failed) - The server was unable to maintain the 412 (Precondition Failed) - A condition header failed. Specific to
liveness of the properties listed in the propertybehavior XML element MOVE, this could mean that the Overwrite header is "F" and the
or the Overwrite header is "F" and the state of the destination destination URL is already mapped to a resource.
resource is non-null.
423 (Locked) - The source or the destination resource was locked. 423 (Locked) - The source or the destination resource, the source or
destination resource parent, or some resource within the source or
destination collection, was locked. This response SHOULD contain the
'lock-token-submitted' precondition element.
502 (Bad Gateway) - This may occur when the destination is on another 502 (Bad Gateway) - This may occur when the destination is on another
server and the destination server refuses to accept the resource. server and the destination server refuses to accept the resource.
8.9.5. Example - MOVE of a Non-Collection This could also occur when the destination is on another sub-section
of the same server namespace.
9.9.5. Example - MOVE of a Non-Collection
This example shows resource This example shows resource
http://www.ics.uci.edu/~fielding/index.html being moved to the http://www.example.com/~fielding/index.html being moved to the
location http://www.ics.uci.edu/users/f/fielding/index.html. The location http://www.example.com/users/f/fielding/index.html. The
contents of the destination resource would have been overwritten if contents of the destination resource would have been overwritten if
the destination resource had been non-null. In this case, since the destination URL was already mapped to a resource. In this case,
there was nothing at the destination resource, the response code is since there was nothing at the destination resource, the response
201 (Created). code is 201 (Created).
>>Request >>Request
MOVE /~fielding/index.html HTTP/1.1 MOVE /~fielding/index.html HTTP/1.1
Host: www.ics.uci.edu Host: www.example.com
Destination: http://www.ics.uci.edu/users/f/fielding/index.html Destination: http://www.example/users/f/fielding/index.html
>>Response >>Response
HTTP/1.1 201 Created HTTP/1.1 201 Created
Location: http://www.ics.uci.edu/users/f/fielding/index.html Location: http://www.example.com/users/f/fielding/index.html
8.9.6. Example - MOVE of a Collection 9.9.6. Example - MOVE of a Collection
>>Request >>Request
MOVE /container/ HTTP/1.1 MOVE /container/ HTTP/1.1
Host: www.foo.bar Host: www.example.com
Destination: http://www.foo.bar/othercontainer/ Destination: http://www.example.com/othercontainer/
Overwrite: F Overwrite: F
If: (<opaquelocktoken:fe184f2e-6eec-41d0-c765-01adc56e6bb4>) If: (<urn:uuid:fe184f2e-6eec-41d0-c765-01adc56e6bb4>)
(<opaquelocktoken:e454f3f3-acdc-452a-56c7-00a5c91e4b77>) (<urn:uuid:e454f3f3-acdc-452a-56c7-00a5c91e4b77>)
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?>
<d:propertybehavior xmlns:d='DAV:'>
<d:keepalive>*</d:keepalive>
</d:propertybehavior>
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<d:multistatus xmlns:d='DAV:'> <d:multistatus xmlns:d='DAV:'>
<d:response> <d:response>
<d:href>http://www.foo.bar/othercontainer/C2/</d:href> <d:href>http://www.example.com/othercontainer/C2/</d:href>
<d:status>HTTP/1.1 423 Locked</d:status> <d:status>HTTP/1.1 423 Locked</d:status>
</d:response> <d:error><d:lock-token-submitted/></d:error>
</d:multistatus> </d:response>
</d:multistatus>
In this example the client has submitted a number of lock tokens with In this example the client has submitted a number of lock tokens with
the request. A lock token will need to be submitted for every the request. A lock token will need to be submitted for every
resource, both source and destination, anywhere in the scope of the resource, both source and destination, anywhere in the scope of the
method, that is locked. In this case the proper lock token was not method, that is locked. In this case the proper lock token was not
submitted for the destination http://www.foo.bar/othercontainer/C2/. submitted for the destination
http://www.example.com/othercontainer/C2/. This means that the
This means that the resource /container/C2/ could not be moved. resource /container/C2/ could not be moved. Because there was an
Because there was an error copying /container/C2/, none of error moving /container/C2/, none of /container/C2's members were
/container/C2's members were copied. However no errors were listed moved. However no errors were listed for those members due to the
for those members due to the error minimization rules given in error minimization rules. User agent authentication has previously
Section 8.8.3. User agent authentication has previously occurred via occurred via a mechanism outside the scope of the HTTP protocol, in
a mechanism outside the scope of the HTTP protocol, in an underlying an underlying transport layer.
transport layer.
8.10. LOCK Method 9.10. LOCK Method
The following sections describe the LOCK method, which is used to The following sections describe the LOCK method, which is used to
take out a lock of any access type. These sections on the LOCK take out a lock of any access type and to refresh an existing lock.
method describe only those semantics that are specific to the LOCK These sections on the LOCK method describe only those semantics that
method and are independent of the access type of the lock being are specific to the LOCK method and are independent of the access
requested. type of the lock being requested.
Any resource which supports the LOCK method MUST, at minimum, support Any resource which supports the LOCK method MUST, at minimum, support
the XML request and response formats defined herein. the XML request and response formats defined herein.
8.10.1. Operation This method is neither idempotent nor safe (see Section 9.1 of
[RFC2616]). Responses to this method MUST NOT be cached.
A LOCK method invocation creates the lock specified by the lockinfo 9.10.1. Creating a Lock on an Existing Resource
XML element on the Request-URI. Lock method requests SHOULD have a
XML request body which contains an owner XML element for this lock
request, unless this is a refresh request. The LOCK request may have
a Timeout header.
Clients MUST assume that locks may arbitrarily disappear at any time, A LOCK request to an existing resource will create a lock on the
regardless of the value given in the Timeout header. The Timeout resource identified by the Request-URI, provided the resource is not
header only indicates the behavior of the server if "extraordinary" already locked with a conflicting lock. The resource identified in
circumstances do not occur. For example, an administrator may remove the Request-URI becomes the root of the lock. Lock method requests
a lock at any time or the system may crash in such a way that it to create a new lock MUST have an XML request body. The server MUST
loses the record of the lock's existence. The response MUST contain preserve the information provided by the client in the 'owner' field
the value of the lockdiscovery property in a prop XML element. in the request body when the lock information is requested. The LOCK
request MAY have a Timeout header.
In order to indicate the lock token associated with a newly created When a new lock is created, the LOCK response:
lock, a Lock-Token response header MUST be included in the response
for every successful LOCK request for a new lock. Note that the
Lock-Token header would not be returned in the response for a
successful refresh LOCK request because a new lock was not created.
8.10.2. The Effect of Locks on Properties and Collections o MUST contain a body with the value of the DAV:lockdiscovery
property in a prop XML element. This MUST contain the full
information about the lock just granted, while information about
other (shared) locks is OPTIONAL.
The scope of a lock is the entire state of the resource, including o MUST include the Lock-Token response header with the token
its body and associated properties. As a result, a lock on a associated with the new lock.
resource MUST also lock the resource's properties.
For collections, a lock also affects the ability to add or remove 9.10.2. Refreshing Locks
members. The nature of the effect depends upon the type of access
control involved.
8.10.3. Locking Replicated Resources A lock is refreshed by sending a LOCK request to the URL of a
resource within the scope of the lock. This request MUST NOT have a
body and it MUST specify which lock to refresh by using the 'If'
header with a single lock token (only one lock may be refreshed at a
time). The request MAY contain a Timeout header, which a server MAY
accept to change the duration remaining on the lock to the new value.
A server MUST ignore the Depth header on a LOCK refresh.
A resource may be made available through more than one URI. However If the resource has other (shared) locks, those locks are unaffected
locks apply to resources, not URIs. Therefore a LOCK request on a by a lock refresh. Additionally, those locks do not prevent the
resource MUST NOT succeed if can not be honored by all the URIs named lock from being refreshed.
through which the resource is addressable.
8.10.4. Depth and Locking The Lock-Token header is not returned in the response for a
successful refresh LOCK request, but the LOCK response body MUST
contain the new value for the DAV:lockdiscovery property.
9.10.3. Depth and Locking
The Depth header may be used with the LOCK method. Values other than The Depth header may be used with the LOCK method. Values other than
0 or infinity MUST NOT be used with the Depth header on a LOCK 0 or infinity MUST NOT be used with the Depth header on a LOCK
method. All resources that support the LOCK method MUST support the method. All resources that support the LOCK method MUST support the
Depth header. Depth header.
A Depth header of value 0 means to just lock the resource specified A Depth header of value 0 means to just lock the resource specified
by the Request-URI. by the Request-URI.
If the Depth header is set to infinity then the resource specified in If the Depth header is set to infinity then the resource specified in
the Request-URI along with all its internal members, all the way down the Request-URI along with all its members, all the way down the
the hierarchy, are to be locked. A successful result MUST return a hierarchy, are to be locked. A successful result MUST return a
single lock token which represents all the resources that have been single lock token. Similarly, if an UNLOCK is successfully executed
locked. If an UNLOCK is successfully executed on this token, all on this token, all associated resources are unlocked. Hence, partial
associated resources are unlocked. If the lock cannot be granted to success is not an option for LOCK or UNLOCK. Either the entire
all resources, a 409 (Conflict) status code MUST be returned with a hierarchy is locked or no resources are locked.
response entity body containing a multistatus XML element describing
which resource(s) prevented the lock from being granted. Hence, If the lock cannot be granted to all resources, the server MUST
partial success is not an option. Either the entire hierarchy is return a Multi-Status response with a 'response' element for at least
locked or no resources are locked. one resource which prevented the lock from being granted, along with
a suitable status code for that failure (e.g. 403 (Forbidden) or 423
(Locked)). Additionally, if the resource causing the failure was not
the resource requested, then the server SHOULD include a 'response'
element for the Request-URI as well, with a 'status' element
containing 424 Failed Dependency.
If no Depth header is submitted on a LOCK request then the request If no Depth header is submitted on a LOCK request then the request
MUST act as if a "Depth:infinity" had been submitted. MUST act as if a "Depth:infinity" had been submitted.
8.10.5. Interaction with other Methods 9.10.4. Locking Unmapped URLs
The interaction of a LOCK with various methods is dependent upon the A successful LOCK method MUST result in the creation of an empty
lock type. However, independent of lock type, a successful DELETE of resource which is locked (and which is not a collection), when a
a resource MUST cause all of its locks to be removed. resource did not previously exist at that URL. Later on, the lock
may go away but the empty resource remains. Empty resources MUST
then appear in PROPFIND responses including that URL in the response
scope. A server MUST respond successfully to a GET request to an
empty resource, either by using a 204 No Content response, or by
using 200 OK with a Content-Length header indicating zero length
8.10.6. Lock Compatibility Table 9.10.5. Lock Compatibility Table
The table below describes the behavior that occurs when a lock The table below describes the behavior that occurs when a lock
request is made on a resource. request is made on a resource.
+-----------------------------------+-------------+----------------+ +--------------------------+----------------+-------------------+
| Current lock state / Lock request | Shared Lock | Exclusive Lock | | Current State | Shared Lock OK | Exclusive Lock OK |
+-----------------------------------+-------------+----------------+ +--------------------------+----------------+-------------------+
| None | True | True | | None | True | True |
| Shared Lock | True | False | | | | |
| Exclusive Lock | False | False* | | Shared Lock | True | False |
+-----------------------------------+-------------+----------------+ | | | |
| Exclusive Lock | False | False* |
+--------------------------+----------------+-------------------+
Legend: True = lock may be granted. False = lock MUST NOT be Legend: True = lock may be granted. False = lock MUST NOT be
granted. *=It is illegal for a principal to request the same lock granted. *=It is illegal for a principal to request the same lock
twice. twice.
The current lock state of a resource is given in the leftmost column, The current lock state of a resource is given in the leftmost column,
and lock requests are listed in the first row. The intersection of a and lock requests are listed in the first row. The intersection of a
row and column gives the result of a lock request. For example, if a row and column gives the result of a lock request. For example, if a
shared lock is held on a resource, and an exclusive lock is shared lock is held on a resource, and an exclusive lock is
requested, the table entry is "false", indicating the lock must not requested, the table entry is "false", indicating the lock must not
be granted. be granted.
8.10.7. Status Codes 9.10.6. LOCK Responses
200 (OK) - The lock request succeeded and the value of the In addition to the general status codes possible, the following
lockdiscovery property is included in the body. status codes have specific applicability to LOCK:
412 (Precondition Failed) - The included lock token was not 200 (OK) - The LOCK request succeeded and the value of the DAV:
enforceable on this resource or the server could not satisfy the lockdiscovery property is included in the response body.
request in the lockinfo XML element.
423 (Locked) - The resource is locked, so the method has been 201 (Created) - The LOCK request was to an unmapped URL, the request
rejected. succeeded and resulted in the creation of a new resource, and the
value of the DAV:lockdiscovery property is included in the response
body.
8.10.8. Example - Simple Lock Request 409 (Conflict) - A resource cannot be created at the destination
until one or more intermediate collections have been created. The
server MUST NOT create those intermediate collections automatically.
423 (Locked), potentially with 'no-conflicting-lock' precondition
code - There is already a lock on the resource which is not
compatible with the requested lock (see lock compatibility table
above).
412 (Precondition Failed), with 'lock-token-matches-request-uri'
precondition code - The LOCK request was made with a If header,
indicating that the client wishes to refresh the given lock.
However, the Request-URI did not fall within the scope of the lock
identified by the token. The lock may have a scope that does not
include the Request-URI, or the lock could have disappeared, or the
token may be invalid.
9.10.7. Example - Simple Lock Request
>>Request >>Request
LOCK /workspace/webdav/proposal.doc HTTP/1.1 LOCK /workspace/webdav/proposal.doc HTTP/1.1
Host: webdav.sb.aol.com Host: example.com
Timeout: Infinite, Second-4100000000 Timeout: Infinite, Second-4100000000
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
Authorization: Digest username="ejw", Authorization: Digest username="ejw",
realm="ejw@webdav.sb.aol.com", nonce="...", realm="ejw@example.com", nonce="...",
uri="/workspace/webdav/proposal.doc", uri="/workspace/webdav/proposal.doc",
response="...", opaque="..." response="...", opaque="..."
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:lockinfo xmlns:D='DAV:'> <D:lockinfo xmlns:D='DAV:'>
<D:lockscope><D:exclusive/></D:lockscope> <D:lockscope><D:exclusive/></D:lockscope>
<D:locktype><D:write/></D:locktype> <D:locktype><D:write/></D:locktype>
<D:owner> <D:owner>
<D:href>http://www.ics.uci.edu/~ejw/contact.html</D:href> <D:href>http://example.org/~ejw/contact.html</D:href>
</D:owner> </D:owner>
</D:lockinfo> </D:lockinfo>
>>Response >>Response
HTTP/1.1 200 OK HTTP/1.1 200 OK
Content-Type: text/xml; charset="utf-8" Lock-Token: <urn:uuid:e71d4fae-5dec-22d6-fea5-00a0c91e6be4>
Content-Length: xxxx Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:prop xmlns:D="DAV:"> <D:prop xmlns:D="DAV:">
<D:lockdiscovery> <D:lockdiscovery>
<D:activelock> <D:activelock>
<D:locktype><D:write/></D:locktype> <D:locktype><D:write/></D:locktype>
<D:lockscope><D:exclusive/></D:lockscope> <D:lockscope><D:exclusive/></D:lockscope>
<D:depth>Infinity</D:depth> <D:depth>infinity</D:depth>
<D:owner> <D:owner>
<D:href> <D:href>http://example.org/~ejw/contact.html</D:href>
http://www.ics.uci.edu/~ejw/contact.html </D:owner>
</D:href> <D:timeout>Second-604800</D:timeout>
</D:owner> <D:locktoken>
<D:timeout>Second-604800</D:timeout> <D:href
<D:locktoken> >urn:uuid:e71d4fae-5dec-22d6-fea5-00a0c91e6be4</D:href>
<D:href> </D:locktoken>
opaquelocktoken:e71d4fae-5dec-22d6-fea5-00a0c91e6be4 <D:lockroot>
</D:href> <D:href
</D:locktoken> >http://example.com/workspace/webdav/proposal.doc</D:href>
</D:activelock> </D:lockroot>
</D:lockdiscovery> </D:activelock>
</D:prop> </D:lockdiscovery>
</D:prop>
This example shows the successful creation of an exclusive write lock This example shows the successful creation of an exclusive write lock
on resource http://webdav.sb.aol.com/workspace/webdav/proposal.doc. on resource http://example.com/workspace/webdav/proposal.doc. The
The resource http://www.ics.uci.edu/~ejw/contact.html contains resource http://example.org/~ejw/contact.html contains contact
contact information for the owner of the lock. The server has an information for the creator of the lock. The server has an activity-
activity-based timeout policy in place on this resource, which causes based timeout policy in place on this resource, which causes the lock
the lock to automatically be removed after 1 week (604800 seconds). to automatically be removed after 1 week (604800 seconds). Note that
Note that the nonce, response, and opaque fields have not been the nonce, response, and opaque fields have not been calculated in
calculated in the Authorization request header. the Authorization request header.
8.10.9. Example - Refreshing a Write Lock 9.10.8. Example - Refreshing a Write Lock
>>Request >>Request
LOCK /workspace/webdav/proposal.doc HTTP/1.1 LOCK /workspace/webdav/proposal.doc HTTP/1.1
Host: webdav.sb.aol.com Host: example.com
Timeout: Infinite, Second-4100000000 Timeout: Infinite, Second-4100000000
If: (<opaquelocktoken:e71d4fae-5dec-22d6-fea5-00a0c91e6be4>) If: (<urn:uuid:e71d4fae-5dec-22d6-fea5-00a0c91e6be4>)
Authorization: Digest username="ejw", Authorization: Digest username="ejw",
realm="ejw@webdav.sb.aol.com", nonce="...", realm="ejw@example.com", nonce="...",
uri="/workspace/webdav/proposal.doc", uri="/workspace/webdav/proposal.doc",
response="...", opaque="..." response="...", opaque="..."
>>Response >>Response
HTTP/1.1 200 OK HTTP/1.1 200 OK
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:prop xmlns:D="DAV:"> <D:prop xmlns:D="DAV:">
<D:lockdiscovery> <D:lockdiscovery>
<D:activelock> <D:activelock>
<D:locktype><D:write/></D:locktype> <D:locktype><D:write/></D:locktype>
<D:lockscope><D:exclusive/></D:lockscope> <D:lockscope><D:exclusive/></D:lockscope>
<D:depth>Infinity</D:depth> <D:depth>infinity</D:depth>
<D:owner> <D:owner>
<D:href> <D:href>http://example.org/~ejw/contact.html</D:href>
http://www.ics.uci.edu/~ejw/contact.html </D:owner>
</D:href> <D:timeout>Second-604800</D:timeout>
</D:owner> <D:locktoken>
<D:timeout>Second-604800</D:timeout> <D:href
<D:locktoken> >urn:uuid:e71d4fae-5dec-22d6-fea5-00a0c91e6be4</D:href>
<D:href> </D:locktoken>
opaquelocktoken:e71d4fae-5dec-22d6-fea5-00a0c91e6be4 <D:lockroot>
</D:href> <D:href
</D:locktoken> >http://example.com/workspace/webdav/proposal.doc</D:href>
</D:activelock> </D:lockroot>
</D:lockdiscovery> </D:activelock>
</D:prop> </D:lockdiscovery>
</D:prop>
This request would refresh the lock, resetting any time outs. Notice This request would refresh the lock, attempting to reset the timeout
that the client asked for an infinite time out but the server choose to the new value specified in the timeout header. Notice that the
to ignore the request. In this example, the nonce, response, and client asked for an infinite time out but the server choose to ignore
opaque fields have not been calculated in the Authorization request the request. In this example, the nonce, response, and opaque fields
header. have not been calculated in the Authorization request header.
8.10.10. Example - Multi-Resource Lock Request 9.10.9. Example - Multi-Resource Lock Request
>>Request >>Request
LOCK /webdav/ HTTP/1.1 LOCK /webdav/ HTTP/1.1
Host: webdav.sb.aol.com Host: example.com
Timeout: Infinite, Second-4100000000 Timeout: Infinite, Second-4100000000
Depth: infinity Depth: infinity
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
Authorization: Digest username="ejw", Authorization: Digest username="ejw",
realm="ejw@webdav.sb.aol.com", nonce="...", realm="ejw@example.com", nonce="...",
uri="/workspace/webdav/proposal.doc", uri="/workspace/webdav/proposal.doc",
response="...", opaque="..." response="...", opaque="..."
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:lockinfo xmlns:D="DAV:"> <D:lockinfo xmlns:D="DAV:">
<D:locktype><D:write/></D:locktype> <D:locktype><D:write/></D:locktype>
<D:lockscope><D:exclusive/></D:lockscope> <D:lockscope><D:exclusive/></D:lockscope>
<D:owner> <D:owner>
<D:href>http://www.ics.uci.edu/~ejw/contact.html</D:href> <D:href>http://example.org/~ejw/contact.html</D:href>
</D:owner> </D:owner>
</D:lockinfo> </D:lockinfo>
>>Response >>Response
HTTP/1.1 207 Multi-Status HTTP/1.1 207 Multi-Status
Content-Type: text/xml; charset="utf-8" Content-Type: application/xml; charset="utf-8"
Content-Length: xxxx Content-Length: xxxx
<?xml version="1.0" encoding="utf-8" ?> <?xml version="1.0" encoding="utf-8" ?>
<D:multistatus xmlns:D="DAV:"> <D:multistatus xmlns:D="DAV:">
<D:response> <D:response>
<D:href>http://webdav.sb.aol.com/webdav/secret</D:href> <D:href>http://example.com/webdav/secret</D:href>
<D:status>HTTP/1.1 403 Forbidden</D:status> <D:status>HTTP/1.1 403 Forbidden</D:status>
</D:response> </D:response>
<D:response> <D:response>
<D:href>http://webdav.sb.aol.com/webdav/</D:href> <D:href>http://example.com/webdav/</D:href>
<D:propstat> <D:status>HTTP/1.1 424 Failed Dependency</D:status>
<D:prop><D:lockdiscovery/></D:prop> </D:response>
<D:status>HTTP/1.1 424 Failed Dependency</D:status> </D:multistatus>
</D:propstat>
</D:response>
</D:multistatus>
This example shows a request for an exclusive write lock on a This example shows a request for an exclusive write lock on a
collection and all its children. In this request, the client has collection and all its children. In this request, the client has
specified that it desires an infinite length lock, if available, specified that it desires an infinite length lock, if available,
otherwise a timeout of 4.1 billion seconds, if available. The otherwise a timeout of 4.1 billion seconds, if available. The
request entity body contains the contact information for the request entity body contains the contact information for the
principal taking out the lock, in this case a web page URL. principal taking out the lock, in this case a web page URL.
The error is a 403 (Forbidden) response on the resource The error is a 403 (Forbidden) response on the resource
http://webdav.sb.aol.com/webdav/secret. Because this resource could http://example.com/webdav/secret. Because this resource could not be
not be locked, none of the resources were locked. Note also that the locked, none of the resources were locked. Note also that the a
lockdiscovery property for the Request-URI has been included as 'response' element for the Request-URI itself has been included as
required. In this example the lockdiscovery property is empty which required.
means that there are no outstanding locks on the resource.
In this example, the nonce, response, and opaque fields have not been In this example, the nonce, response, and opaque fields have not been
calculated in the Authorization request header. calculated in the Authorization request header.
8.11. UNLOCK Method 9.11. UNLOCK Method
The UNLOCK method removes the lock identified by the lock token in The UNLOCK method removes the lock identified by the lock token in
the Lock-Token request header from the Request-URI, and all other the Lock-Token request header. The Request-URI MUST identify a
resources included in the lock. If all resources which have been resource within the scope of the lock.
locked under the submitted lock token can not be unlocked then the
UNLOCK request MUST fail. Note that use of Lock-Token header to provide the lock token is not
consistent with other state-changing methods which all require an If
header with the lock token. Thus, the If header is not needed to
provide the lock token. Naturally when the If header is present it
has its normal meaning as a conditional header.
For a successful response to this method, the server MUST delete the
lock entirely.
If all resources which have been locked under the submitted lock
token can not be unlocked then the UNLOCK request MUST fail.
A successful response to an UNLOCK method does not mean that the
resource is necessarily unlocked. It means that the specific lock
corresponding to the specified token no longer exists.
Any DAV compliant resource which supports the LOCK method MUST Any DAV compliant resource which supports the LOCK method MUST
support the UNLOCK method. support the UNLOCK method.
8.11.1. Example - UNLOCK This method is idempotent, but not safe (see Section 9.1 of
[RFC2616]). Responses to this method MUST NOT be cached.
9.11.1. Status Codes
In addition to the general status codes possible, the following
status codes have specific applicability to UNLOCK:
204 (No Content) - Normal success response (rather than 200 OK, since
200 OK would imply a response body, and an UNLOCK success response
does not normally contain a body)
400 (Bad Request) - No lock token was provided.
403 (Forbidden) - The currently authenticated principal does not have
permission to remove the lock.
409 (Conflict), with 'lock-token-matches-request-uri' precondition -
The resource was not locked, or the request was made to a Request-URI
that was not within the scope of the lock.
9.11.2. Example - UNLOCK
>>Request >>Request
UNLOCK /workspace/webdav/info.doc HTTP/1.1 UNLOCK /workspace/webdav/info.doc HTTP/1.1
Host: webdav.sb.aol.com Host: example.com
Lock-Token: <opaquelocktoken:a515cfa4-5da4-22e1-f5b5-00a0451e6bf7> Lock-Token: <urn:uuid:a515cfa4-5da4-22e1-f5b5-00a0451e6bf7>
Authorization: Digest username="ejw", Authorization: Digest username="ejw"
realm="ejw@webdav.sb.aol.com", nonce="...", realm="ejw@example.com", nonce="...",
uri="/workspace/webdav/proposal.doc", uri="/workspace/webdav/proposal.doc",
response="...", opaque="..." response="...", opaque="..."
>>Response >>Response
HTTP/1.1 204 No Content HTTP/1.1 204 No Content
In this example, the lock identified by the lock token In this example, the lock identified by the lock token
"opaquelocktoken:a515cfa4-5da4-22e1-f5b5-00a0451e6bf7" is "urn:uuid:a515cfa4-5da4-22e1-f5b5-00a0451e6bf7" is successfully
successfully removed from the resource removed from the resource
http://webdav.sb.aol.com/workspace/webdav/info.doc. If this lock http://example.com/workspace/webdav/info.doc. If this lock included
included more than just one resource, the lock is removed from all more than just one resource, the lock is removed from all resources
resources included in the lock. The 204 (No Content) status code is included in the lock.
used instead of 200 (OK) because there is no response entity body.
In this example, the nonce, response, and opaque fields have not been In this example, the nonce, response, and opaque fields have not been
calculated in the Authorization request header. calculated in the Authorization request header.
9. HTTP Headers for Distributed Authoring 10. HTTP Headers for Distributed Authoring
9.1. DAV Header All DAV headers follow the same basic formatting rules as HTTP
headers. This includes rules like line continuation and how to
combine (or separate) multiple instances of the same header using
commas.
DAV = "DAV" ":" "1" ["," "2"] ["," 1#extend] WebDAV adds two new conditional headers to the set defined in HTTP:
the If and Overwrite headers.
This header indicates that the resource supports the DAV schema and 10.1. DAV Header
protocol as specified. All DAV compliant resources MUST return the
DAV header on all OPTIONS responses.
The value is a list of all compliance classes that the resource DAV = "DAV" ":" #( compliance-class )
supports. Note that above a comma has already been added to the 2. compliance-class = ( "1" | "2" | "3" | extend )
This is because a resource can not be level 2 compliant unless it is extend = Coded-URL | token
also level 1 compliant. Please refer to Section 15 for more details. Coded-URL = "<" absolute-URI ">"
In general, however, support for one compliance class does not entail ; No linear white space (LWS) allowed in Coded-URL
support for any other. ; absolute-URI is defined in RFC3986
9.2. Depth Header This general-header appearing in the response indicates that the
resource supports the DAV schema and protocol as specified. All DAV
compliant resources MUST return the DAV header with compliance-class
"1" on all OPTIONS responses. In cases where WebDAV is only
supported in part of the server namespace, an OPTIONS request to non-
WebDAV resources (including "/") SHOULD NOT advertise WebDAV support.
The value is a comma-separated list of all compliance class
identifiers that the resource supports. Class identifiers may be
Coded-URLs or tokens (as defined by [RFC2616]). Identifiers can
appear in any order. Identifiers that are standardized through the
IETF RFC process are tokens, but other identifiers SHOULD be Coded-
URLs to encourage uniqueness.
A resource must show class 1 compliance if it shows class 2 or 3
compliance. In general, support for one compliance class does not
entail support for any other, and in particular, support for
compliance class 3 does not require support for compliance class 2.
Please refer to Section 18 for more details on compliance classes
defined in this specification.
Note that many WebDAV servers do not advertise WebDAV support in
response to "OPTIONS *".
As a request header, this header allows the client to advertise
compliance with named features when the server needs that
information. Clients SHOULD NOT send this header unless a standards
track specification requires it. Any extension that makes use of
this as a request header will need to carefully consider caching
implications.
10.2. Depth Header
Depth = "Depth" ":" ("0" | "1" | "infinity") Depth = "Depth" ":" ("0" | "1" | "infinity")
The Depth header is used with methods executed on resources which The Depth request header is used with methods executed on resources
could potentially have internal members to indicate whether the which could potentially have internal members to indicate whether the
method is to be applied only to the resource ("Depth: 0"), to the method is to be applied only to the resource ("Depth: 0"), to the
resource and its immediate children, ("Depth: 1"), or the resource resource and its internal members only, ("Depth: 1"), or the resource
and all its progeny ("Depth: infinity"). and all its members ("Depth: infinity").
The Depth header is only supported if a method's definition The Depth header is only supported if a method's definition
explicitly provides for such support. explicitly provides for such support.
The following rules are the default behavior for any method that The following rules are the default behavior for any method that
supports the Depth header. A method may override these defaults by supports the Depth header. A method may override these defaults by
defining different behavior in its definition. defining different behavior in its definition.
Methods which support the Depth header may choose not to support all Methods which support the Depth header may choose not to support all
of the header's values and may define, on a case by case basis, the of the header's values and may define, on a case by case basis, the
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hierarchies in any particular order or on the execution being atomic hierarchies in any particular order or on the execution being atomic
unless the particular method explicitly provides such guarantees. unless the particular method explicitly provides such guarantees.
Upon execution, a method with a Depth header will perform as much of Upon execution, a method with a Depth header will perform as much of
its assigned task as possible and then return a response specifying its assigned task as possible and then return a response specifying
what it was able to accomplish and what it failed to do. what it was able to accomplish and what it failed to do.
So, for example, an attempt to COPY a hierarchy may result in some of So, for example, an attempt to COPY a hierarchy may result in some of
the members being copied and some not. the members being copied and some not.
Any headers on a method that has a defined interaction with the Depth By default, the Depth header does not interact with other headers.
header MUST be applied to all resources in the scope of the method That is, each header on a request with a Depth header MUST be applied
except where alternative behavior is explicitly defined. For only to the Request-URI if it applies to any resource, unless
example, an If-Match header will have its value applied against every specific Depth behavior is defined for that header.
resource in the method's scope and will cause the method to fail if
the header fails to match.
If a resource, source or destination, within the scope of the method If a resource, source or destination, within the scope of the method
with a Depth header is locked in such a way as to prevent the with a Depth header is locked in such a way as to prevent the
successful execution of the method, then the lock token for that successful execution of the method, then the lock token for that
resource MUST be submitted with the request in the If request header. resource MUST be submitted with the request in the If request header.
The Depth header only specifies the behavior of the method with The Depth header only specifies the behavior of the method with
regards to internal children. If a resource does not have internal regards to internal members. If a resource does not have internal
children then the Depth header MUST be ignored. members then the Depth header MUST be ignored.
Please note, however, that it is always an error to submit a value 10.3. Destination Header
for the Depth header that is not allowed by the method's definition.
Thus submitting a "Depth: 1" on a COPY, even if the resource does not
have internal members, will result in a 400 (Bad Request). The
method should fail not because the resource doesn't have internal
members, but because of the illegal value in the header.
9.3. Destination Header The Destination request header specifies the URI which identifies a
destination resource for methods such as COPY and MOVE, which take
two URIs as parameters.
Destination = "Destination" ":" absoluteURI Destination = "Destination" ":" Simple-ref
The Destination header specifies the URI which identifies a If the Destination value is an absolute-URI (Section 4.3 of
destination resource for methods such as COPY and MOVE, which take [RFC3986]), it may name a different server (or different port or
two URIs as parameters. Note that the absoluteURI production is scheme). If the source server cannot attempt a copy to the remote
defined in [RFC2396]. server, it MUST fail the request. Note that copying and moving
resources to remote servers is not fully defined in this
specification (e.g. specific error conditions).
9.4. If Header If the Destination value is too long or otherwise unacceptable, the
server SHOULD return 400 (Bad Request), ideally with helpful
information in an error body.
If = "If" ":" ( 1*No-tag-list | 1*Tagged-list) 10.4. If Header
No-tag-list = List
Tagged-list = Resource 1*List
Resource = Coded-URL
List = "(" 1*(["Not"](State-token | "[" entity-tag "]")) ")"
State-token = Coded-URL
Coded-URL = "<" absoluteURI ">"
The If header is intended to have similar functionality to the If- The If request header is intended to have similar functionality to
Match header defined in section 14.25 of [RFC2068]. However the If the If-Match header defined in Section 14.24 of [RFC2616]. However
header is intended for use with any URI which represents state the If header handles any state token as well as ETags. A typical
information, referred to as a state token, about a resource as well example of a state token is a lock token, and lock tokens are the
as ETags. A typical example of a state token is a lock token, and only state tokens defined in this specification.
lock tokens are the only state tokens defined in this specification.
All DAV compliant resources MUST honor the If header. 10.4.1. Purpose
The If header's purpose is to describe a series of state lists. If The If header has two distinct purposes:
the state of the resource to which the header is applied does not
match any of the specified state lists then the request MUST fail
with a 412 (Precondition Failed). If one of the described state
lists matches the state of the resource then the request may succeed.
Note that the absoluteURI production is defined in [RFC2396]. o The first purpose is to make a request conditional by supplying a
series of state lists with conditions that match tokens and ETags
to specific resource. If this header is evaluated and all state
lists fail, then the request MUST fail with a 412 (Precondition
Failed) status. On the other hand, the request can succeed only
if one of the described state lists succeeds. The success
criteria for state lists and matching functions are defined in
Section 10.4.3 and Section 10.4.4.
9.4.1. No-tag-list Production o Additionally, the mere fact that a state token appears in an If
header means that it has been "submitted" with the request. In
general, this is used to indicate that the client has knowledge of
that state token. The semantics for submitting a state token
depend on its type (for lock tokens, please refer to Section 6).
The No-tag-list production describes a series of state tokens and Note that these two purposes need to be treated distinctly: a state
ETags. If multiple No-tag-list productions are used then one only token counts as being submitted independently of whether the server
needs to match the state of the resource for the method to be allowed actually has evaluated the state list it appears in, and also
to continue. independently of whether the condition it expressed was found to be
true or not.
If a method, due to the presence of a Depth or Destination header, is 10.4.2. Syntax
applied to multiple resources then the No-tag-list production MUST be
applied to each resource the method is applied to.
9.4.1.1. Example - No-tag-list If Header If = "If" ":" ( 1*No-tag-list | 1*Tagged-list )
If: (<locktoken:a-write-lock-token> ["I am an ETag"]) (["I am another No-tag-list = List
ETag"]) Tagged-list = Resource-Tag 1*List
The previous header would require that any resources within the scope List = "(" 1*Condition ")"
of the method must either be locked with the specified lock token and Condition = ["Not"] (State-token | "[" entity-tag "]")
in the state identified by the "I am an ETag" ETag or in the state ; entity-tag: see Section 3.11 of [RFC2616]
identified by the second ETag "I am another ETag". To put the matter ; No LWS allowed between "[", entity-tag and "]"
more plainly one can think of the previous If header as being in the
form (or (and <locktoken:a-write-lock-token> ["I am an ETag"]) (and
["I am another ETag"])).
9.4.2. Tagged-list Production State-token = Coded-URL
The tagged-list production scopes a list production. That is, it Resource-Tag = "<" Simple-ref ">"
specifies that the lists following the resource specification only ; Simple-ref: see Section 8.3
apply to the specified resource. The scope of the resource ; No LWS allowed in Resource-Tag
production begins with the list production immediately following the
resource production and ends with the next resource production, if
any.
When the If header is applied to a particular resource, the Tagged- The syntax distinguishes between untagged lists ("No-tag-list") and
list productions MUST be searched to determine if any of the listed tagged lists ("Tagged-list"). Untagged lists apply to the resource
resources match the operand resource(s) for the current method. If identified by the Request-URI, while tagged lists apply to the
none of the resource productions match the current resource then the resource identified by the preceding Resource-Tag.
header MUST be ignored. If one of the resource productions does
match the name of the resource under consideration then the list
productions following the resource production MUST be applied to the
resource in the manner specified in the previous section.
The same URI MUST NOT appear more than once in a resource production A Resource-Tag applies to all subsequent Lists, up to the next
in an If header. Resource-Tag.
9.4.2.1. Example - Tagged List If header Note that the two list types cannot be mixed within an If header.
This is not a functional restriction because the No-tag-list syntax
is just a shorthand notation for a Tagged-list production with a
Resource-Tag referring to the Request-URI.
COPY /resource1 HTTP/1.1 Each List consists of one or more Conditions. Each Condition is
Host: www.foo.bar defined in terms of an entity-tag or state-token, potentially negated
Destination: http://www.foo.bar/resource2 by the prefix "Not".
If: <http://www.foo.bar/resource1> (<locktoken:a-write-lock-token>
[W/"A weak ETag"]) (["strong ETag"])
<http://www.bar.bar/random>(["another strong ETag"])
In this example http://www.foo.bar/resource1 is being copied to Note that the If header syntax does not allow multiple instances of
http://www.foo.bar/resource2. When the method is first applied to If headers in a single request. However, the HTTP header syntax
http://www.foo.bar/resource1, resource1 must be in the state allows extending single header values across multiple lines, by
specified by "(<locktoken:a-write-lock-token> [W/"A weak ETag"]) inserting a line break followed by whitespace (see [RFC2616], Section
(["strong ETag"])", that is, it either must be locked with a lock 4.2).
token of "locktoken:a-write-lock-token" and have a weak entity tag
W/"A weak ETag" or it must have a strong entity tag "strong ETag".
That is the only success condition since the resource 10.4.3. List Evaluation
http://www.bar.bar/random never has the method applied to it (the
only other resource listed in the If header) and
http://www.foo.bar/resource2 is not listed in the If header.
9.4.3. not Production A Condition that consists of a single entity-tag or state-token
evaluates to true if the resource matches the described state (where
the individual matching functions are defined below in
Section 10.4.4). Prefixing it with "Not" reverses the result of the
evaluation (thus, the "Not" applies only to the subsequent entity-tag
or state-token).
Every state token or ETag is either current, and hence describes the Each List production describes a series of conditions. The whole
state of a resource, or is not current, and does not describe the list evaluates to true if and only if each condition evaluates to
state of a resource. The boolean operation of matching a state token true (that is, the list represents a logical conjunction of
or ETag to the current state of a resource thus resolves to a true or Conditions).
false value. The not production is used to reverse that value. The
scope of the not production is the state-token or entity-tag
immediately following it.
If: (Not <locktoken:write1> <locktoken:write2>) Each No-tag-list and Tagged-list production may contain one or more
Lists. They evaluate to true if and only if any of the contained
lists evaluates to true (that is, if there's more than one List, that
List sequence represents a logical disjunction of the Lists).
When submitted with a request, this If header requires that all Finally, the whole If header evaluates to true if and only if at
operand resources must not be locked with locktoken:write1 and must least one of the No-tag-list or Tagged-list productions evaluates to
be locked with locktoken:write2. true. If the header evaluates to false, the server MUST reject the
request with a 412 (Precondition Failed) status. Otherwise,
execution of the request can proceed as if the header wasn't present.
9.4.4. Matching Function 10.4.4. Matching State Tokens and ETags
When performing If header processing, the definition of a matching When performing If header processing, the definition of a matching
state token or entity tag is as follows. state token or entity tag is as follows:
Identifying a resource: The resource is identified by the URI along
with the token, in tagged list production, or by the Request-URI in
untagged list production.
Matching entity tag: Where the entity tag matches an entity tag Matching entity tag: Where the entity tag matches an entity tag
associated with that resource. associated with the identified resource. Servers MUST use either the
weak or the strong comparison function defined in Section 13.3.3 of
[RFC2616].
Matching state token: Where there is an exact match between the state Matching state token: Where there is an exact match between the state
token in the If header and any state token on the resource. token in the If header and any state token on the identified
resource. A lock state token is considered to match if the resource
is anywhere in the scope of the lock.
9.4.5. If Header and Non-DAV Compliant Proxies Handling unmapped URLs: for both ETags and state tokens, treat as if
the URL identified a resource that exists but does not have the
specified state.
Non-DAV compliant proxies will not honor the If header, since they 10.4.5. If Header and Non-DAV Aware Proxies
will not understand the If header, and HTTP requires non-understood
Non-DAV aware proxies will not honor the If header, since they will
not understand the If header, and HTTP requires non-understood
headers to be ignored. When communicating with HTTP/1.1 proxies, the headers to be ignored. When communicating with HTTP/1.1 proxies, the
"Cache-Control: no-cache" request header MUST be used so as to client MUST use the "Cache-Control: no-cache" request header so as to
prevent the proxy from improperly trying to service the request from prevent the proxy from improperly trying to service the request from
its cache. When dealing with HTTP/1.0 proxies the "Pragma: no-cache" its cache. When dealing with HTTP/1.0 proxies the "Pragma: no-cache"
request header MUST be used for the same reason. request header MUST be used for the same reason.
9.5. Lock-Token Header As in general clients may not be able to reliably detect non-DAV
aware intermediates, they are advised to always prevent caching using
the request directives mentioned above.
10.4.6. Example - No-tag Production
If: (<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>
["I am an ETag"])
(["I am another ETag"])
The previous header would require that the resource identified in the
Request-URI be locked with the specified lock token and be in the
state identified by the "I am an ETag" ETag or in the state
identified by the second ETag "I am another ETag".
To put the matter more plainly one can think of the previous If
header as expressing the condition below:
(
is-locked-with(urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2) AND
matches-etag("I am an ETag")
)
OR
(
matches-etag("I am another ETag")
)
10.4.7. Example - using "Not" with No-tag Production
If: (Not <urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>
<urn:uuid:58f202ac-22cf-11d1-b12d-002035b29092>)
This If header requires that the resource must not be locked with a
lock having the lock token
urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2 and must be locked by a
lock with the lock token
urn:uuid:58f202ac-22cf-11d1-b12d-002035b29092.
10.4.8. Example - causing a Condition to always evaluate to True
There may be cases where a client wishes to submit state tokens, but
doesn't want the request to fail just because the state token isn't
current anymore. One simple way to do this is to include a Condition
that is known to always evaluate to true, such as in:
If: (<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>)
(Not <DAV:no-lock>)
"DAV:no-lock" is known to never represent a current lock token, as
lock tokens are assigned by the server, following the uniqueness
requirements described in Section 6.5, therefore in particular
exclude URIs in the "DAV:" scheme. Thus, by applying "Not" to a
known not to be current state token, the Condition always evaluates
to true. Consequently, the whole If header will always evaluate to
true, and the lock token
urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2 will be submitted in
any case.
10.4.9. Example - Tagged List If header in COPY
>>Request
COPY /resource1 HTTP/1.1
Host: www.example.com
Destination: /resource2
If: </resource1>
(<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>
[W/"A weak ETag"]) (["strong ETag"])
In this example http://www.example.com/resource1 is being copied to
http://www.example.com/resource2. When the method is first applied
to http://www.example.com/resource1, resource1 must be in the state
specified by "(<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2> [W/"A
weak ETag"]) (["strong ETag"])", that is, it either must be locked
with a lock token of "urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2"
and have a weak entity tag W/"A weak ETag" or it must have a strong
entity tag "strong ETag".
10.4.10. Example - Matching lock tokens with collection locks
DELETE /specs/rfc2518.txt HTTP/1.1
Host: www.example.com
If: <http://www.example.com/specs/>
(<urn:uuid:181d4fae-7d8c-11d0-a765-00a0c91e6bf2>)
For this example, the lock token must be compared to the identified
resource, which is the 'specs' collection identified by the URL in
the tagged list production. If the 'specs' collection is not locked
by a lock with the specified lock token, the request MUST fail.
Otherwise, this request could succeed, because the If header
evaluates to true, and because the lock token for the lock affecting
the affected resource has been submitted.
10.4.11. Example - Matching ETags on unmapped URLs
Consider a collection "/specs" that does not contain the member
"/specs/rfc2518.doc". In this case, the If header
If: </specs/rfc2518.doc> (["4217"])
will evaluate to false (the URI isn't mapped, thus the