W3C home > Mailing lists > Public > w3c-dist-auth@w3.org > January to March 2004

Re: edits on BIND draft

From: Julian Reschke <julian.reschke@gmx.de>
Date: Sun, 11 Jan 2004 13:01:57 +0100
Message-ID: <40013B35.9080803@gmx.de>
To: webdav <w3c-dist-auth@w3.org>

Julian Reschke wrote:


On

<http://greenbytes.de/tech/webdav/draft-ietf-webdav-bind-latest.html>:

    Add and close issues "9.2_redirect_loops", "ED_authors" and
    "ED_updates". Add section about capability discovery (DAV header).
    Close issues "5.1_LOOP_STATUS".

In particular, the explanation for status 208 has been rewritten stating 
that it will only occur for collections upon Depth: infinity, the 
example has been fixed (DAV header added) and another example for a 
non-BIND-aware client was added. In addition, in section 8 the 
description for the DAV *request* header has been expanded.

Feedback appreciated,

Julian

- TXT version of the updated sections -

7. Additional Status Codes

7.1 208 Already Reported

    The 208 (Already Reported) status code can be used inside a
    DAV:propstat response element to avoid enumerating the internal
    members of multiple bindings to the same collection repeatedly.  For
    each binding to a collection inside the request's scope, only one
    will be reported with a 200 status, while subsequent DAV:response
    elements for all other bindings will use the 208 status, and no
    DAV:response elements for their descendants are included.

    Note that the 208 status will only occur for "Depth: infinity"
    requests, and that it is of particular importance when the multiple
    collection bindings cause a bind loop as discussed in Section 2.2.

    A client can request the DAV:resourceid property in a PROPFIND
    request to guarantee that they can accurately reconstruct the binding
    structure of a collection with multiple bindings to a single
    resource.

    For backward compatibility with clients not aware of the 208 status
    code appearing in multistatus response bodies, it SHOULD NOT be used
    unless the client has signalled support for this specification using
    the "DAV" request header (see Section 8.2). Otherwise the entire
    PROPFIND request MUST fail with the 506 status described below.

7.1.1 Example: PROPFIND by bind-aware client

    For example, consider a PROPFIND request on /Coll (bound to
    collection C), where the members of  /Coll are /Coll/Foo (bound to
    resource R) and /Coll/Bar (bound to collection C).

    >> Request:

    PROPFIND /Coll/ HTTP/1.1
    Host: www.example.com
    Depth: infinity
    DAV: bind
    Content-Type: text/xml; charset="utf-8"
    Content-Length: xxx

    <?xml version="1.0" encoding="utf-8" ?>
    <D:propfind xmlns:D="DAV:">
       <D:prop> <D:displayname/> </D:prop>
    </D:propfind>


    >> Response:

    HTTP/1.1 207 Multi-Status
    Content-Type: text/xml; charset="utf-8"
    Content-Length: xxx

    <?xml version="1.0" encoding="utf-8" ?>
    <D:multistatus xmlns:D="DAV:">
       <D:response>
          <D:href>http://www.example.com/Coll/</D:href>
          <D:propstat>
             <D:prop>
                <D:displayname>Loop Demo</D:displayname>
             </D:prop>
             <D:status>HTTP/1.1 200 OK</D:status>
          </D:propstat>
       </D:response>
       <D:response>
          <D:href>http://www.example.com/Coll/Foo</D:href>
          <D:propstat>
             <D:prop>
                <D:displayname>Bird Inventory</D:displayname>
             </D:prop>
             <D:status>HTTP/1.1 200 OK</D:status>
          </D:propstat>
       </D:response>
       <D:response>
          <D:href>http://www.example.com/Coll/Bar</D:href>

          <D:propstat>
             <D:prop>
                <D:displayname>Loop Demo</D:displayname>
             </D:prop>
             <D:status>HTTP/1.1 208 Already Reported</D:status>
          </D:propstat>
       </D:response>
    </D:multistatus>


7.1.2 Example: PROPFIND by non-bind-aware client

    In this example, the client isn't aware of the 208 status code
    introduced by this specification.  As the "Depth: infinity" PROPFIND
    request would cause a loop condition, the whole request is rejected
    with a 506 status.

    >> Request:

    PROPFIND /Coll/ HTTP/1.1
    Host: www.example.com
    Depth: infinity
    Content-Type: text/xml; charset="utf-8"
    Content-Length: xxx

    <?xml version="1.0" encoding="utf-8" ?>
    <D:propfind xmlns:D="DAV:">
       <D:prop> <D:displayname/> </D:prop>
    </D:propfind>

    >> Response:

    HTTP/1.1 506 Loop Detected


7.2 506 Loop Detected

    The 506 (Loop Detected) status code indicates that the server
    terminated an operation because it encountered an infinite loop while
    processing a request with "Depth: infinity".   This status indicates
    that the entire operation failed.

8. Capability discovery

8.1 OPTIONS method

    If the server supports bindings, it MUST return the compliance class
    name "bind" as a field in the "DAV" response header (see [RFC2518],
    section 9.1) from an OPTIONS request on any resource implemented by
    that server. A value of "bind" in the "DAV" header MUST indicate that
    the server supports all MUST level requirements and REQUIRED features
    specified in this document.

8.2 'DAV' request header

8.2.1 Generic syntax

    This specification introduces the 'DAV' request header that allows
    clients to signal compliance to specific WebDAV features. It has the
    same syntax as the response header defined in [RFC2518], section 9.1,
    but MAY be used with any method.

    Note that clients MUST NOT submit a specific compliance class name in
    the request header unless the specification defining this compliance
    class specifically defines it's semantics for clients.

    Note that if a server chooses to vary the result of a request based
    on values in the "DAV" header, the response either MUST NOT be
    cacheable or the server MUST mark the response accordingly using the
    "Vary" header (see [RFC2616], section 14.44).

8.2.2 Client compliance class 'bind'

    Clients SHOULD signal support for all MUST level requirements and
    REQUIRED features by submitting a "DAV" request header containing the
    compliance class name "bind".  In particular, the client MUST
    understand the 208 status code defined in Section 7.1.


-- 
<green/>bytes GmbH -- http://www.greenbytes.de -- tel:+492512807760
Received on Sunday, 11 January 2004 07:02:56 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 5 February 2014 07:17:51 UTC