WebDAV Collections December 10, 1998 Judy Slein

WebDAV Advanced Collections2 Issues n Properties of Direct References n Optional Backpointers n Hiding the Target n Definition of “Weak Reference”

WebDAV Advanced Collections3 Properties of Direct References n Re-Direct header overrides default behavior for any method on a direct reference n Makes direct references behave like redirect references for that request n Makes it possible to access and update the properties of the reference

WebDAV Advanced Collections4 Rationale n Be able to access the properties of the reference –DAV:resourcetype, DAV:reftype, etc. –creator, create date, comment n Be able to modify properties of the reference that were set via headers at creation time –DAV:hidetarget, DAV:refintegrity n For versioning –Specifying different default revisions when accessed from different collections?

WebDAV Advanced Collections5 Optional Backpointers n DAV:references property on a target resource lists all references to it n Read-only property for security reasons

WebDAV Advanced Collections6 Rationale n Scenario: Server declines to delete target because there are references to it. Client must discover the references in order to delete them so that the target can be deleted. n Scenario: Server does not maintain referential integrity. Client wants to be a good citizen by checking for references before deleting a resource. n Scenario: DMS client wants to display a list of all collections that a target belongs to by reference, so that users can navigate to those collections to find related documents or see how the target resource is being used.

WebDAV Advanced Collections7 Proposal: Hiding the Target n Drop this requirement: “When creating a direct reference, it is possible to request that the location of its target be hidden.”

WebDAV Advanced Collections8 Rationale n The constraint really belongs at the target, not at the reference n Added test for the server for every request on a direct reference

WebDAV Advanced Collections9 Proposal: Weak References n Values for Ref-Integrity header are –DAV:weak –DAV:serverdefault n Values for DAV:refintegrity property are –DAV:weak –DAV:serverdefault

WebDAV Advanced Collections10 Rationale: Weak References n Requirement: It is possible when creating a reference to request that the server not enforce referential integrity for that reference –Populate a directory with references before their targets are created –Temporarily remove targets without having to destroy / recreate references to them