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

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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.¶

Versioned Resource ¶

• When a resource is put under version control, it becomes a “versioned resource”. A versioned resource can be “checked out” to allow modification.

Version History ¶

• A “version history” resource is a resource that contains all the versions of a particular versioned resource.

Predecessor, Successor ¶

• When a versioned resource is checked out and then subsequently checked in, the version that was checked out becomes a “predecessor” of the version created by the checkin. A client can specify multiple predecessors for a new version if the new version is logically a merge of those predecessors. The inverse of the predecessor relation is the “successor” relation. Therefore, if X is a predecessor of Y, then Y is a successor of X.

Working Copy ¶

• A “working copy” is a resource at a server-defined URL that can be modified to create a new version of a versioned resource.

version-history ¶

• When included on a versioned resource, this link points to a resource containing the version history for this resource.

latest-version ¶

• When included on a versioned resource, this link points to a resource containing the latest (e.g., current) version.
• The latest version is defined by the system. For linear versioning systems, this is probably the latest version by timestamp. For systems that support branching, there will be multiple latest versions, one for each branch in the version history.
• Some systems may allow multiple of these link relations.

working-copy ¶

• When included on a versioned resource, this link points to a working copy for this resource.
• Some systems may allow multiple of these link relations.

predecessor-version ¶

• When included on a versioned resource, this link points to a resource containing the predecessor version in the version history.
• Some systems may allow multiple of these link relations in the case of a multiple branches merging.

successor-version ¶

• When included on a versioned resource, this link points to a resource containing the successor version in the version history.
• Some systems may allow multiple of these link relations in order to support branching.

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

The link relations defined in Section 3 are to be registered by IANA per [RFC4287]. [lhdraft: Will be updated to follow [draft-nottingham-http-link-header] once approved by the IESG. –jre] ¶

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

• Undefined; this relation can be used for background processing or to provide extended functionality without displaying its value.

version-history ¶

• WebDAV: the resource identified by the DAV:version-history property ([RFC3253], Sections 5.2.1 and 5.3.1).
• JCR: the node identified by jcr:versionHistory property ([JSR-283], Section 3.13.2.4) for versionable nodes, the parent folder for version nodes.

latest-version ¶

• WebDAV: for version-controlled resources, DAV:checked-in ([RFC3253], Section 3.2.1) or DAV:checked-out ([RFC3253], Section 3.3.1), depending on checkin state. For version resources, a successor version that itself does not have any successors.
• JCR: the version node identified by the jcr:baseVersion property ([JSR-283], Section 3.13.2.5) for versionable nodes; for version nodes, a successor version that itself does not have any successors.

working-resource ¶

• WebDAV: for version-controlled resources that are checked-out in place: the resource itself. For version resources: each resource identified by a member of the DAV:checkout-set property (see [RFC3253], Section 3.4.3).
• JCR: for checked-out versionable nodes: the node itself.

predecessor-version ¶

• WebDAV: each resource identified by a member of DAV:predecessor-set ([RFC3253], Sections 3.3.2 and 3.4.1).
• JCR: each node identified by a member of jcr:predecessors ([JSR-283], Section 3.13.3.3).

successor-version ¶

• WebDAV: each resource identified by a member of DAV:successor-set ([RFC3253], Section 3.4.2).
• JCR: each node identified by a member of jcr:successors ([JSR-283], Section 3.13.3.4).

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.¶