HTTP, WebDAV, and POST

[Ken MacLeod <ken@xxxxxxxxxxxxxxxx>]

Very good descriptions by Mark and John!  I wanted to add that it may
not have to be an either/or situation, and there are advantages to
both techniques.  Just a few notes:

 * As noted by Julian, for this first round of Atom specs we don't
   need to "use WebDAV", we can specify Atom usage of basic HTTP
   methods that are inherently upwardly compatible with WebDAV.

 * Eventually, Atom will grow up to need robustness or collaborative
   features like transactions, locking, ACLs, etc.  This is the scope
   and purpose of WebDAV, so assuming Atom would eventually add these
   operations "into its API" would be unnecessary and conflicting
   work.  The scope of work Atom can focus on can be much smaller:
   setting the context of using WebDAV for journal and chronological
   resources.

 * I'm already somewhat concerned about Atom developing a new, unique
   way of associating metadata with arbitrary web resources (when
   people talk of "posting metadata after they post their cat
   picture").  WebDAV already does support that.  I'm not concerned
   about this in the context of textual Atom entries, though, as
   entries are complete resources in-and-of-themselves.

 * Although nominally a "web resource", a large number of people seem
   not to think of entries managed through the Atom API as actionable
   web resources, they seem to think of them like XML records
   manipulated through the Atom API.  This perspective may hinder
   eventually using WebDAV facilities like transactions, locking, and
   ACLs on entries themselves.

 * Although WebDAV does not use POST, there does not seem to be any
   conflict in Atom specifying POST for creating server-located
   resources and at some point using WebDAV actions on the resources
   after they've been created.

 * Additionally supporting PUT-to-create for arbitrary resources (in
   the current discussion), and for entries (separate discussion)
   positions Atom to be upwardly compatible with WebDAV.

  -- Ken