Subject: RE: WebDAV Bindings - Issue Yaron.ApplePieToo

From: "Slein, Judith A" <[email-masked]>
Date: Wed, 2 Feb 2000 16:55:39 -0500

This is a resend to encourage the mailing list to comment on this proposed
language.  The authors are considering whether to replace Section 9 of the
Bindings spec with one or the other of these passages:

---------- Proposal 1

Here's some text that doesn't mention static / dynamic.  It doesn't make the
simple, idealized statement that we wanted for static resources, but maybe
it says enough to be useful:

"This section describes the interaction of bindings with those HTTP methods
not yet explicitly discussed.  The semantics of the methods GET, HEAD, PUT,
POST and OPTIONS are specified in [HTTP].  The semantics of PROPFIND,
PROPPATCH, and MKCOL are specified in [WebDAV].

"For these methods, no new complexities are introduced by allowing explicit
creation of multiple bindings to the same resource.  However, the
introduction of the BIND method will make it more common for multiple URIs
to map to the same resource.  As a result, the introduction of the BIND
method may point up complexities that were already possible, but occurred
only rarely in the past.  

"In particular, when there are multiple URI mappings to the same resource,
it is possible for the resource's behavior in response to GET, HEAD,
PROPFIND, etc., to be sensitive to the URI that was used to make the
request.  For example, the Request-URI may appear in the response entity
body for GET on a particular resource, in which case the response entity
body produced by that resource will differ depending upon which URI was used
to make the request.

"The only way for a client to determine whether two URIs map to the same
resource is by retrieving and comparing the DAV:resourceid property defined
in the following section."

--------- Proposal 2

"This section describes the interaction of bindings with those HTTP methods
not yet explicitly discussed.  The semantics of the methods GET, HEAD, PUT,
POST and OPTIONS are specified in [HTTP].  The semantics of PROPFIND,
PROPPATCH, and MKCOL are specified in [WebDAV].

"For these methods, no new complexities are introduced by allowing explicit
creation of multiple bindings to the same resource.  However, the
introduction of the BIND method will make it more common for multiple URIs
to map to the same resource.  When these methods are applied to the same
resource using different Request-URIs, the rules for their behavior depend
upon whether the resource is static or dynamic.

"A static resource is one that always produces the same response to the same
method with identiical parameters.

"A dynamic resource is one that may produce different responses for
different submissions of the same method with identical parameters.

"In reality, a single resource may respond statically to some requests, but
dynamically to others.  However, for a pure static resource, these methods
obey the folowing rule:

"o  A method submitted through one URI mapping, on success, MUST produce the
same results as the same method, with the same headers and entity body,
submitted through any other URI mapping to the same resource.

"When applied to dynamic resources, it is not possible to state any such
rule.  For any method, a dynamic resource may be sensitive to the URI
mapping used to access it.  The resource may produce different results
depending upon which URI mapping was used to submit the request."

--Judy

Judith A. Slein
Xerox Corporation
[email-masked]
(716)422-5169
800 Phillips Road 105/50C
Webster, NY 14580