Namespace consistency

Larry Masinter writes:
># DAV compliant
>#   resources MUST maintain the consistency of the HTTP URL namespace.
>
>Is there a definition of what 'the consistency of the HTP URL namespace'
>means? It's not defined anywhere, and this sentence only gives an example.

This does appear to be an omission in the specification.

By consistency, we meant:

No gaps: Given HTTP URL U, for all unique HTTP URL Ux, where Ux is
constructed from U by removing all characters to the right of a "/", Ux MUST
be the HTTP URL of a WebDAV collection.

So, if there is an HTTP URL:

http://www.foo.bar.org/a/b/c

Then

http://www.foo.bar.org/a/b/
http://www.foo.bar.org/a/

MUST be HTTP URLs of WebDAV collection resources.

There are two ways to maintain this consistency when a new resource is
created:

a) create intermediate collections automatically
b) refuse to create a resource if intermediate collections do not yet exist.

The example in Section 4.3 implies we were recommending option b).

Also, consistency implies:

100% containment: Given HTTP URL U, U MUST be a member URL of the collection
whose URL, Uc, is contructed by removing the trailing path segment of U.
Exception: when U is the top-level resource, "/", of a namespace (i.e., the
first slash after the domain name in an HTTP URL), it belongs to no
collection, since it is the URI of the root collection.

- Jim