Network Working GroupA. Brown
Intended status: InformationalJ. Reschke
Expires: December 14, 2009greenbytes
June 12, 2009

Link Relations for Simple Version Navigation

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This specification defines Atom link relations for navigation between a resource and its versions.

Editorial Note (To be removed by RFC Editor before publication)

Please send comments to the Atom Syntax mailing list (<>).

1. Introduction

This specification defines link relations that may be used on a resource that exists in a system that supports versioning to navigate among the different resources available, such as past versions.

2. Terminology

The terms below are borrowed from the Versioning Extensions to WebDAV (Web Distributed Authoring and Versioning) ([RFC3253]).

Version-Controlled Resource, Checked-Out

Checked-Out Resource

Version Resource

Version History Resource

Predecessor, Successor, Ancestor, Descendant

Root Version Resource

Working Resource

3. Link Relations

The following link relations are defined:

When included on a version controlled resource, this link points to a resource containing the version history for this resource.
When included on a version controlled resource, this link points to a resource containing the latest (e.g., current) version. [issue.latest.version: I think "latest" is misleading, as it may not be the "latest" when different branches are involved. JCR 1.0 has "base version", defined as "The base version of a particular node N is the one that will serve as the default immediate predecessor of the next version of N that is created." -- can we adopt that? (see <>). --jre]
When included on a Checked-Out resource, this link points to a Working Resource. [issue.working.resource.2: I think the working resource *is* checked out, and the link lives on either a version or version controlled resource (which stays checked in). --jre]
When included on a version resource, this link points to a resource containing the predecessor version in the version history.
When included on a version resource, this link points to a resource containing the successor version in the version history.

4. Examples

[rfc.comment.1: To Be Done]

5. Security Considerations

Automated agents should take care when these relation crosses administrative domains (e.g., the URI has a different authority than the current document).

6. IANA Considerations

The link relations defined in Section 3 are to be registered by IANA per [RFC4287].

All link relations defined in this document will have the following expected display characteristics:

7. References

7.1. Normative References

Nottingham, M. and R. Sayre, “The Atom Syndication Format”, RFC 4287, December 2005.

7.2. Informative References

Clemm, G., Amsden, J., Ellison, T., Kaler, C., and J. Whitehead, “Versioning Extensions to WebDAV (Web Distributed Authoring and Versioning)”, RFC 3253, March 2002.

Appendix A. Relationship to JCR and WebDAV

[rfc.comment.2: To Be Done: describe how versioning properties in JCR and in WebDAV/DeltaV map to the newly defined link relations.]

Appendix B. Contributors

The content and concepts within are a product of the Content Management Interoperability Services (CMIS) Technical Committee (TC) at OASIS.

All members of the TC have contributed.

Authors' Addresses

Al Brown
3565 Harbor Blvd
Costa Mesa, California 92626
Julian F. Reschke
greenbytes GmbH
Hafenweg 16
Muenster, NW 48155