eZ component: Webdav, RFC overview, 1.0
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

:Author: Kore Nordmann, Tobias Schlitt
:Revision: $Rev$
:Date: $Date$
:Status: Draft

.. contents::

Scope
~~~~~

This document tries to summarize the major points of `RFC 2518`_, which seem
important for the realization of the Webdav component of eZ Components in
version 1.0. This document does not contain any design decisions, but only
rephrased contents of the original RFC document. For the design document please
refer to design.txt.

.. _`RFC 2518`: http://www.ietf.org/rfc/rfc2518.txt

General
~~~~~~~

This section contains information that is generally valid for any or, at least,
a certain set of opertaions. Operation specific information can be found in the
next section.

==========
Properties
==========

Properties are meta-data for a resource. Each property consists of a name (the
tag name actually) and a value (the contents of the tag). In requests and
responses, they are defined using the <prop> tag, which can contain any number
of properties.

Live properties
===============

Live properties must be supported by every DAV resource and the server is
responsible for validating their values. Beside that, a server must support
"dead properties", which it simply needs to store, but it does not need to take
care about validation.

<!ELEMENT creationdate (#PCDATA) >
  The creattion date of the resource.
  The #PCDATA in this tag must accord to ISO 8601 Date and Time Profile.
  Example: ::
    <creationdate>2007-08-29T11:35:01Z</creationdate>

<!ELEMENT displayname (#PCDATA) >
  A name for the resource that is suitable to be displayed to the user (e.g.
  the filename).
  Example: ::
    <displayname>test.gif</displayname>

<!ELEMENT getcontentlanguage (#PCDATA) >
  Contains language information as provided by the HTTP Content-Language
  header.
  Example: ::
    <getcontentlanguage>de, en</getcontentlanguage>

<!ELEMENT getcontentlength (#PCDATA) >
  Contains information about the content size as provided by the HTTP
  Content-Length header.
  Example: ::
    <getcontentlength>123456</getcontentlength>

<!ELEMENT getcontenttype (#PCDATA) >
  Contains information about the content type as provided by the HTTP
  Content-Type header.
  Example: ::
    <getcontenttype>text/html; charset=ISO-8859-4</getcontenttype>

<!ELEMENT getetag (#PCDATA) >
  Contains the etag (indicator of change) for the resource as provided by the
  HTTP ETag header.
  Example: ::
    <getetag>...</getetag>

<!ELEMENT getlastmodified (#PCDATA) >
  Contains the last modification date of the resource as provided by the
  Last-Modified header.
  Example: ::
     <getlastmodified>Sun, 06 Nov 1994 08:49:37 GMT</getlastmodified>


<!ELEMENT lockdiscovery (activelock)* >
  Returns a list of lock information for the resource, including information on
  who has a lock, the type of the lock, expiration time and type of the timeout
  as well as the associated lock token.
  Example: ::
    <D:lockdiscovery>
         <D:activelock>
              <D:locktype><D:write/></D:locktype>
              <D:lockscope><D:exclusive/></D:lockscope>
              <D:depth>0</D:depth>
              <D:owner>Jane Smith</D:owner>
              <D:timeout>Infinite</D:timeout>
              <D:locktoken>
                   <D:href>
    opaquelocktoken:f81de2ad-7f3d-a1b2-4f3c-00a0c91a9d76
                   </D:href>
              </D:locktoken>
         </D:activelock>
    </D:lockdiscovery>

<!ELEMENT resourcetype ANY >
  Defines the type of the resource. Not further speicified how this must look
  like. Default is empty, but the tag must be present. 
  Example: ::
  <resourcetype />

<!ELEMENT source (link)* >
  Specifies resources where the source files of a processed resource can be
  found. This is used, if a desired resource is processed by the server in some
  way, before being delivered. Using this property, the client can get hold of
  the un-processed sources of the resource.
  Example: ::
    <D:source>
          <D:link>
               <D:src>http://foo.bar/program</D:src>
               <D:dst>http://foo.bar/src/main.c</D:dst>
          </D:link>
          <D:link>
               <D:src>http://foo.bar/program</D:src>
               <D:dst>http://foo.bar/src/main.lib</D:dst>
          </D:link>
          <D:link>
               <D:src>http://foo.bar/program</D:src>
               <D:dst>http://foo.bar/src/makefile</D:dst>
          </D:link>
     </D:source>

<!ELEMENT supportedlock (lockentry)* >
  Returns a list of supported lock types and scopes of a resource.
  Example: ::
    <D:supportedlock>
         <D:lockentry>
              <D:lockscope><D:exclusive/></D:lockscope>
              <D:locktype><D:write/></D:locktype>
         </D:lockentry>
         <D:lockentry>
              <D:lockscope><D:shared/></D:lockscope>
              <D:locktype><D:write/></D:locktype>
         </D:lockentry>
    </D:supportedlock>

=======
Headers
=======

Some headers (either for request or response purpose) are used in general by
WebDav communication, which are described here.

If
--

The "If" header is used (similarly to "If-Match" in pure HTTP) to indicate a
certain state of the desired resource. The content provided by the header is a
list of state tokens. If a resource, affected by the given resource, does not
match any of the state tokens, the request must fail with code 412
(Precondition Failed).

The only place where the "If" header is used in WebDav is for opaquelocktokens.

The exact BNF definition of this header can be seen in the RFC in section 9.4.

Status-URI
----------

This header can be used for a process that takes longer than the
request-response communication can be kept up. In this case, the client can
repeatedly request the given URI to check the status of the process.

This header is used in combination with the 102 (Processing) e.g. as an answer
to a MOVE operation.

Operations
~~~~~~~~~~

This section contains operation specific information.

===
PUT
===

Replaces the content which will be returned by GET. Live properties may be
recalculated - for example the content type may be set from the corresponding
header passed to the server.a

Header
======

None special.

Response
========

Codes
-----

Example response codes to be returned by this request.

201 (Created)
  The resource was created in its entity.

409 (Conflict)
  If parent node does not exists, or is no collection.

========
PROPFIND
========

Retrieves information on the properties of the resource identified by the
Request-URI. Three different ways of finding properties are possible:

- Retrieve a list of certain property names and the correcsponding values.
- Retrieve a list of all available property names for a resource, without their
  corresponding values.
- Retrieve a single property name and the correcsponding value.

PROPFIND can work recursively on the given resource, if this is a collection.
The "Depth" header determines, what level of recursion is desired.

Header
======

Depth
-----

Defines the search-depth of the resources to search properties for. The Depth
header can have the values "0", "1" or "infinity". If the header is not
provided, "inifinity" is asumed, which means that the operation is performed
recursively down to the leave nodes. A depth of "0" means, that only the
resource itself and none of its children is taken into accound and "1" means
that only first level descendants are taken into account.

XML
===

<!ELEMENT propfind (allprop | propname | prop) >
  Base tag for the PROPFIND request. Only possible XML base tag. Optional for
  the PROPFIND request. If not given, the request is handled as if "allprop"
  was set.

<!ELEMENT allprop EMPTY >
  If this tag is available, a list of all available properties without their
  corresponding values is desired.

<!ELEMENT propname EMPTY >
  The propname XML element specifies that only a list of property names on the
  resource is to be returned.

<!ELEMENT prop ANY>
  The <prop>-XML-element is a generic container for property information. In
  case of a PROPFIND request, it contains an empty property tag for each
  property that should be returned.

Example
=======

Regular PROPFIND request
------------------------

The following request submits 4 property names to the server, for which the
values should be returned. 2 properties are returned successfully in this
example, while access to the other 2 requested properties is forbidden.

::

   >>Request

   PROPFIND  /file HTTP/1.1
   Host: www.foo.bar
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propfind xmlns:D="DAV:">
     <D:prop xmlns:R="http://www.foo.bar/boxschema/">
          <R:bigbox/>
          <R:author/>
          <R:DingALing/>
          <R:Random/>
     </D:prop>
   </D:propfind>

   >>Response

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

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
          <D:href>http://www.foo.bar/file</D:href>
          <D:propstat>
               <D:prop xmlns:R="http://www.foo.bar/boxschema/">
                    <R:bigbox>
                         <R:BoxType>Box type A</R:BoxType>
                    </R:bigbox>
                    <R:author>
                         <R:Name>J.J. Johnson</R:Name>
                    </R:author>
               </D:prop>
               <D:status>HTTP/1.1 200 OK</D:status>
          </D:propstat>
          <D:propstat>
               <D:prop><R:DingALing/><R:Random/></D:prop>
               <D:status>HTTP/1.1 403 Forbidden</D:status>
               <D:responsedescription> The user does not have access to
   the DingALing property.
               </D:responsedescription>
          </D:propstat>
     </D:response>
     <D:responsedescription> There has been an access violation error.
     </D:responsedescription>
   </D:multistatus>


<allprop />-PROPFIND request
----------------------------

In the following example, a request for all available properties and their
values is issued and the proper response is returned.

::

  >>Request

   PROPFIND  /container/ HTTP/1.1
   Host: www.foo.bar
   Depth: 1
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx

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

   >>Response

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

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
          <D:href>http://www.foo.bar/container/</D:href>
          <D:propstat>
               <D:prop xmlns:R="http://www.foo.bar/boxschema/">
                    <R:bigbox>
                         <R:BoxType>Box type A</R:BoxType>
                    </R:bigbox>
                    <R:author>
                         <R:Name>Hadrian</R:Name>
                    </R:author>
                    <D:creationdate>
                         1997-12-01T17:42:21-08:00
                    </D:creationdate>
                    <D:displayname>
                         Example collection
                    </D:displayname>
                    <D:resourcetype><D:collection/></D:resourcetype>
                    <D:supportedlock>
                         <D:lockentry>
                              <D:lockscope><D:exclusive/></D:lockscope>
                              <D:locktype><D:write/></D:locktype>
                         </D:lockentry>
                         <D:lockentry>
                              <D:lockscope><D:shared/></D:lockscope>
                              <D:locktype><D:write/></D:locktype>
                         </D:lockentry>
                    </D:supportedlock>
               </D:prop>
               <D:status>HTTP/1.1 200 OK</D:status>
          </D:propstat>
     </D:response>
     <D:response>
          <D:href>http://www.foo.bar/container/front.html</D:href>
          <D:propstat>
               <D:prop xmlns:R="http://www.foo.bar/boxschema/">
                    <R:bigbox>
                         <R:BoxType>Box type B</R:BoxType>
                    </R:bigbox>
                    <D:creationdate>
                         1997-12-01T18:27:21-08:00
                    </D:creationdate>
                    <D:displayname>
                         Example HTML resource
                    </D:displayname>
                    <D:getcontentlength>
                         4525
                    </D:getcontentlength>
                    <D:getcontenttype>
                         text/html
                    </D:getcontenttype>
                    <D:getetag>
                         zzyzx
                    </D:getetag>
                    <D:getlastmodified>
                         Monday, 12-Jan-98 09:25:56 GMT
                    </D:getlastmodified>
                    <D:resourcetype/>
                    <D:supportedlock>
                         <D:lockentry>
                              <D:lockscope><D:exclusive/></D:lockscope>
                              <D:locktype><D:write/></D:locktype>
                         </D:lockentry>
                         <D:lockentry>
                              <D:lockscope><D:shared/></D:lockscope>
                              <D:locktype><D:write/></D:locktype>
                         </D:lockentry>
                    </D:supportedlock>
               </D:prop>
               <D:status>HTTP/1.1 200 OK</D:status>
          </D:propstat>
     </D:response>
   </D:multistatus>


<propname />-PROPFIND request
-----------------------------

The last PROPFIND example issues a <proname /> tag is send to request the names
of all supported properties.

::

   >>Request

   PROPFIND  /container/ HTTP/1.1
   Host: www.foo.bar
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx

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

   >>Response

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

   <?xml version="1.0" encoding="utf-8" ?>
   <multistatus xmlns="DAV:">
     <response>
          <href>http://www.foo.bar/container/</href>
          <propstat>
               <prop xmlns:R="http://www.foo.bar/boxschema/">
                    <R:bigbox/>
                    <R:author/>
                    <creationdate/>
                    <displayname/>
                    <resourcetype/>
                    <supportedlock/>
               </prop>
               <status>HTTP/1.1 200 OK</status>
          </propstat>
     </response>
     <response>
          <href>http://www.foo.bar/container/front.html</href>
          <propstat>
               <prop xmlns:R="http://www.foo.bar/boxschema/">
                    <R:bigbox/>
                    <creationdate/>
                    <displayname/>
                    <getcontentlength/>
                    <getcontenttype/>
                    <getetag/>
                    <getlastmodified/>
                    <resourcetype/>
                    <supportedlock/>
               </prop>
               <status>HTTP/1.1 200 OK</status>
          </propstat>
     </response>
   </multistatus>

=========
PROPPATCH
=========

Allows the setting, updating and removing of 1 or more properties. 1 request
represents a transaction and can contain multiple manipulations of different
kinds on one resource. If one operation fails, all other operations need to be
reverted.

.. Danger::
   The RFC seems not to state anything about PROPPATCH on collection resources.
   We decided internally to perform the PROPPATCH with a Depth of 0 on
   collections.

Header
======

-


XML
===

<!ELEMENT propertyupdate (remove | set)+ >
  Main element for the PROPPATCH request. Contains a set of property
  manipulations to perform.

<!ELEMENT remove (prop) >
  Indicates that the property given inside <prop /> should be removed from the
  resource. The property element cointained in <prop /> must be empty.

<!ELEMENT set (prop) >
  Indicates that the given property inside the <prop /> element should be set
  to the given value.

Response
========

Codes
-----

Example response codes to be returned by this request.

200 (OK)
  The command succeeded.  As there can be a mixture of sets and removes in a
  body, a 201 (Created) seems inappropriate.

403 (Forbidden)
  The client, for reasons the server chooses not to specify, cannot alter one
  of the properties.

409 (Conflict)
  The client has provided a value whose semantics are not appropriate for the
  property.  This includes trying to set read- only properties.

423 (Locked)
  The specified resource is locked and the client either is not a lock owner or
  the lock type requires a lock token to be submitted and the client did not
  submit it.

424 (Failed Dependency)
  Shown in the example below. Probably used, when one transaction element
  failed, and all others operations had to be reverted.

507 (Insufficient Storage)
  The server did not have sufficient space to record the property.

Example
=======

The PROPPATCH request only has 1 valid format.

::

   >>Request

   PROPPATCH /bar.html HTTP/1.1
   Host: www.foo.com
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propertyupdate xmlns:D="DAV:"
   xmlns:Z="http://www.w3.com/standards/z39.50/">
     <D:set>
          <D:prop>
               <Z:authors>
                    <Z:Author>Jim Whitehead</Z:Author>
                    <Z:Author>Roy Fielding</Z:Author>
               </Z:authors>
          </D:prop>
     </D:set>
     <D:remove>
          <D:prop><Z:Copyright-Owner/></D:prop>
     </D:remove>
   </D:propertyupdate>

   >>Response

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

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:"
   xmlns:Z="http://www.w3.com/standards/z39.50">
     <D:response>
          <D:href>http://www.foo.com/bar.html</D:href>
          <D:propstat>
               <D:prop><Z:Authors/></D:prop>
               <D:status>HTTP/1.1 424 Failed Dependency</D:status>
          </D:propstat>
          <D:propstat>
               <D:prop><Z:Copyright-Owner/></D:prop>
               <D:status>HTTP/1.1 409 Conflict</D:status>
          </D:propstat>
          <D:responsedescription> Copyright Owner can not be deleted or
   altered.</D:responsedescription>
     </D:response>
   </D:multistatus>

=====
MKCOL
=====

The MKCOL request is used to create a new collection resource. Collections
cannot be created using PUT or any other request, but only by MKCOL.

The MKCOL may contain a request body, which is not specified in the RFC. The
request body may define the creation of subsequent collections or ressources
and their properties. The RFC 2518 itself does not define, or make any
examples, how this may look like, but references later RFCs.

.. Note::
  As we only want to support RFC 2518 for now, we always send a 415
  (Unsupported Media Type) response, if a request body is present.

Header
======

-

XML
===

-

Example
=======

The MKCOL request is quite easy.

   >>Request

   MKCOL /webdisc/xfiles/ HTTP/1.1
   Host: www.server.org

   >>Response

   HTTP/1.1 201 Created

Response
========

Codes
-----

Example response codes to be returned by this request.

201 (Created) 
  The collection or structured resource was created in its entirety.

403 (Forbidden)
  This indicates at least one of two conditions: 

  1) the server does not allow the creation of collections at the given
     location in its namespace, or 
  2) the parent collection of the Request-URI exists but cannot accept members.

405 (Method Not Allowed) 
  MKCOL can only be executed on a deleted/non-existent resource.

409 (Conflict) 
  A collection cannot be made at the Request-URI until one or more intermediate
  collections have been created.

415 (Unsupported Media Type)
  The server does not support the request type of the body.

507 (Insufficient Storage)
  The resource does not have sufficient space to record the state of the
  resource after the execution of this method.

======
DELETE
======

Requests to delete a certain resource. May be used on non-collection and
collection resources. If used on collection resources, this request works like
"Depth: Infinity" header is set and deletes all descendants.

Header
======

-

XML
===

-

Example
=======

The following example shows a case were a descendant resource is locked and
therefore the delete failed.

   >>Request

   DELETE  /container/ HTTP/1.1
   Host: www.foo.bar

   >>Response

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

   <?xml version="1.0" encoding="utf-8" ?>
   <d:multistatus xmlns:d="DAV:">
     <d:response>
          <d:href>http://www.foo.bar/container/resource3</d:href>
          <d:status>HTTP/1.1 423 Locked</d:status>
     </d:response>
   </d:multistatus>

====
COPY
====

Creates a duplicate of the requested resource at the destination defined by the
"Destination" header. The state of the duplicate result must match the origin
state as good as possible, regarding content and properties. The depth of the
duplication is defined by the "Depth" header, while the default is 0 here.

The <propertybehaviour /> XML element can be used to define the handling of
properties while copying the resource.

Header
======

Overwrite
---------

Value: T
  The destination is to be DELTED before COPY starts.
Value: F
  If the destination exists, the COPY must fail.

If a child COPY fails, the rest of the COPY must be performed. (No
transactional behaviour!).

Destination
-----------

Defines the destination resource to create a duplicate of the requested
resource at.

Depth
-----

Defined like the "Depth" header for the PROPFIND request. The default value
here is 0, which means to only copy the resource itself and not descendants.

XML
===

<!ELEMENT propertybehavior (omit | keepalive) >
  This XML element may be used to influence the way in which a server handles
  properties during copy.

<!ELEMENT keepalive (#PCDATA | href+) >
  The <keepalive /> element may contain 1 or more URIs (inside a <href />
  each), to define, that the given list must be copied completly "live".
  Alternatively, a * can be given instead of a list of elements, to indicate,
  that all properties must be copied live.

<!ELEMENT omit EMPTY >
  Using this element, instead of <keepalive />, a client indicates to the
  server that it should put "best efforts" into copying properties, but that
  it must not fail, if a property copy fails.

Response
========

Codes
-----

201 (Created)
  The source resource was successfully copied.  The copy operation resulted in
  the creation of a new resource.
204 (No Content)
  The source resource was successfully copied to a pre-existing destination
  resource.
403 (Forbidden)
  The source and destination URIs are the same.
409 (Conflict)
  A resource cannot be created at the destination until one or more
  intermediate collections have been created.
412 (Precondition Failed)
  The server was unable to maintain the liveness of the properties listed in
  the propertybehavior XML element or the Overwrite header is "F" and the state
  of the destination resource is non-null.
423 (Locked)
  The destination resource was locked.
502 (Bad Gateway)
  This may occur when the destination is on another server and the destination
  server refuses to accept the resource.
507 (Insufficient Storage)
  The destination resource does not have sufficient space to record the state
  of the resource after the execution of this method.

Examples
========

Overwriting COPY
----------------

The following example indicates a successful COPY request that has overwritten
the already existing destination resource (note: 204 indicates the overwrite!).

::

   >>Request

   COPY /~fielding/index.html HTTP/1.1
   Host: www.ics.uci.edu
   Destination: http://www.ics.uci.edu/users/f/fielding/index.html

   >>Response

   HTTP/1.1 204 No Content

Non-overwriting COPY
--------------------

In this example, the "Overwrite" header changed the overwriting behaviour.
Because the destination resource exists and cannot be overwritten, COPY fails.

::

   >>Request

   COPY /~fielding/index.html HTTP/1.1
   Host: www.ics.uci.edu
   Destination: http://www.ics.uci.edu/users/f/fielding/index.html
   Overwrite: F

   >>Response

   HTTP/1.1 412 Precondition Failed

Collection COPY
---------------

The following example shows the COPY of a collection resource. The "Depth"
header is just set to the default and could therefore be ignored. The COPY
operation suceeds almost on all resources, except for R2, which has
most-propably a problem with property copying.

::

      >>Request

      COPY /container/ HTTP/1.1
      Host: www.foo.bar
      Destination: http://www.foo.bar/othercontainer/
      Depth: infinity
      Content-Type: text/xml; charset="utf-8"
      Content-Length: xxxx

      <?xml version="1.0" encoding="utf-8" ?>
      <d:propertybehavior xmlns:d="DAV:">
        <d:keepalive>*</d:keepalive>
      </d:propertybehavior>

      >>Response

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

      <?xml version="1.0" encoding="utf-8" ?>
      <d:multistatus xmlns:d="DAV:">
        <d:response>
             <d:href>http://www.foo.bar/othercontainer/R2/</d:href>
             <d:status>HTTP/1.1 412 Precondition Failed</d:status>
        </d:response>
      </d:multistatus>

====
MOVE
====

The MOVE operation behaves similar to the COPY operation, followed by a DELETE
of the original resource. All in all, the MOVE request is handled very similar
to the COPY operation.

.. Danger::
  Like for COPY, the RFC says, that the server should try to copy as much as
  possible in case an error occurs for some subtree for a collection MOVE with
  depth infinity.

  We decide to omit the deletion of the source collection, if an error occured
  during the copy operation, even this is not defined by the RFC.

Header
======

"Overwrite" as described with COPY. "Depth" must not be sent by the client.

XML
===

-

Response
========

Codes
-----

201 (Created)
  The source resource was successfully moved, and a new resource was created at
  the destination.
204 (No Content)
  The source resource was successfully moved to a pre-existing destination
  resource.
403 (Forbidden)
  The source and destination URIs are the same.
409 (Conflict)
  A resource cannot be created at the destination until one or more
  intermediate collections have been created.
412 (Precondition Failed)
  The server was unable to maintain the liveness of the properties listed in
  the propertybehavior XML element or the Overwrite header is "F" and the state
  of the destination resource is non-null.
423 (Locked)
  The source or the destination resource was locked.
502 (Bad Gateway)
  This may occur when the destination is on another server and the destination
  server refuses to accept the resource.

Examples
========

MOVE non-collection
-------------------

The following example shows a successful MOVE operation of a non-collection
resource.

::

   >>Request

   MOVE /~fielding/index.html HTTP/1.1
   Host: www.ics.uci.edu
   Destination: http://www.ics.uci.edu/users/f/fielding/index.html

   >>Response

   HTTP/1.1 201 Created
   Location: http://www.ics.uci.edu/users/f/fielding/index.html

MOVE collection
---------------

In the following example, a collection-resource is MOVED, while a single
child-resource failed.

::

   >>Request

   MOVE /container/ HTTP/1.1
   Host: www.foo.bar
   Destination: http://www.foo.bar/othercontainer/
   Overwrite: F
   If: (<opaquelocktoken:fe184f2e-6eec-41d0-c765-01adc56e6bb4>)
       (<opaquelocktoken:e454f3f3-acdc-452a-56c7-00a5c91e4b77>)
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx
   
   <?xml version="1.0" encoding="utf-8" ?>
   <d:propertybehavior xmlns:d='DAV:'>
     <d:keepalive>*</d:keepalive>
   </d:propertybehavior>

   >>Response

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

   <?xml version="1.0" encoding="utf-8" ?>
   <d:multistatus xmlns:d='DAV:'>
     <d:response>
          <d:href>http://www.foo.bar/othercontainer/C2/</d:href>
          <d:status>HTTP/1.1 423 Locked</d:status>
     </d:response>
   </d:multistatus>

====
LOCK
====

Creates the LOCK descibed by the <lockinfo /> XML element. Can be used to
create a new lock or to refresh an exisiting one. Timeouts can be defined using
the "Timeout" header. The response must contain the created lock information in
a lockdiscovery property. For a new lock, the lock token must be returned in
the "Lock-Token" header.

A lock affects a complete resource, including its properties and (for
collection-resources) adding and removal of collection members. The depth of a
collection lock can be determined by the "Depth" header.

Headers
=======

Timeout
  Allows the client to define a timeout value for the lock. This timeout is not
  mandatory for the server, since locks can also disappear by a system crash or
  administartor intervention. In a normal case, the server should stick to the
  timeout. A timeout may be defined for new locks as well as for refresh
  requests. Multiple timeout alternatives can be defined comma-seperated.
Depth
  Determines the depth of locking for a collection resource. Valid values are
  here only "0" (for only the collection itself) and "infinity". The default
  value is "infinity".
If
  The If-Header, which is commonly used to indicate to a server that oneself is
  the valid owner of a lock, might be present in case of lock refresh requests
  and gives the lock token it requests an update to.
Authorization
  While this header is not directly used by the WebDAV RFC it is commonly used
  to submit various authorization informations, especially in cases of the LOCK
  examples.


XML
===

<!ELEMENT lockinfo (lockscope, locktype, owner?) >
  This element is used as a possible body of the lock request. It is used to
  specify information about the lock to be created using <lockscop />,
  <locktype /> and optionally <owner /> XML elements.
<!ELEMENT lockscope (exclusive | shared) >
  This element must always be present in the <lockinfo /> element and its
  possible (constant) values describe the type of lock.
<!ELEMENT locktype (write) >
  So far the specification only describes 1 possible settings element here,
  which is write. => Only write-locks are possible.
<!ELEMENT owner ANY>
  The optional owner element may contain anything as a description for the
  owner of the lock. Possible would be e.g. a user ID or the URL of the users
  website (see example).

.. Note::
   We asume here 1 of 2 alternatives for the <owner /> element:
   - A <href /> element with a URL
   - A #PCDATA node
   Both will simply be stored as a string and need to be re-serialized
   correctly, if a URI is returned.

Example
-------

::

   <D:lockinfo xmlns:D="DAV:">
     <D:locktype><D:write/></D:locktype>
     <D:lockscope><D:exclusive/></D:lockscope>
     <D:owner>
          <D:href>http://www.ics.uci.edu/~ejw/contact.html</D:href>
     </D:owner>
   </D:lockinfo>


Response
========

Codes
-----

200 (OK)
  The lock request succeeded and the value of the lockdiscovery property is
  included in the body.
412 (Precondition Failed)
  The included lock token was not enforceable on this resource or the server
  could not satisfy the request in the lockinfo XML element.
423 (Locked)
  The resource is locked, so the method has been rejected.

Examples
========

Simple LOCK request
-------------------

The following example shows a simple LOCK request for a non-collection
resource. The request asks for an exclusive write lock, which is successfully
granted. The returnes opaquelocktoken can be used to identify the lock
globally.

::

  >>Request

   LOCK /workspace/webdav/proposal.doc HTTP/1.1
   Host: webdav.sb.aol.com
   Timeout: Infinite, Second-4100000000
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx
   Authorization: Digest username="ejw",
      realm="ejw@webdav.sb.aol.com", nonce="...",
      uri="/workspace/webdav/proposal.doc",
      response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:lockinfo xmlns:D='DAV:'>
     <D:lockscope><D:exclusive/></D:lockscope>
     <D:locktype><D:write/></D:locktype>
     <D:owner>
          <D:href>http://www.ics.uci.edu/~ejw/contact.html</D:href>
     </D:owner>
   </D:lockinfo>

   >>Response

   HTTP/1.1 200 OK
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:prop xmlns:D="DAV:">
     <D:lockdiscovery>
          <D:activelock>
               <D:locktype><D:write/></D:locktype>
               <D:lockscope><D:exclusive/></D:lockscope>
               <D:depth>Infinity</D:depth>
               <D:owner>
                    <D:href>
                         http://www.ics.uci.edu/~ejw/contact.html
                    </D:href>
               </D:owner>
               <D:timeout>Second-604800</D:timeout>
               <D:locktoken>
                    <D:href>
               opaquelocktoken:e71d4fae-5dec-22d6-fea5-00a0c91e6be4
                    </D:href>
               </D:locktoken>
          </D:activelock>
     </D:lockdiscovery>
   </D:prop>

Refreshing a write lock
-----------------------

The second example shows a LOCk request that attempts to refresh an existing
lock. The opaqualocktoken submitted identifies the affected lock. In this
example, the server ignores the timeout values suggested by the client and uses
its default value.

::

   >>Request

   LOCK /workspace/webdav/proposal.doc HTTP/1.1
   Host: webdav.sb.aol.com
   Timeout: Infinite, Second-4100000000
   If: (<opaquelocktoken:e71d4fae-5dec-22d6-fea5-00a0c91e6be4>)
   Authorization: Digest username="ejw",
      realm="ejw@webdav.sb.aol.com", nonce="...",
      uri="/workspace/webdav/proposal.doc",
      response="...", opaque="..."

   >>Response

   HTTP/1.1 200 OK
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:prop xmlns:D="DAV:">
     <D:lockdiscovery>
          <D:activelock>
               <D:locktype><D:write/></D:locktype>
               <D:lockscope><D:exclusive/></D:lockscope>
               <D:depth>Infinity</D:depth>
               <D:owner>
                    <D:href>
                    http://www.ics.uci.edu/~ejw/contact.html
                    </D:href>
               </D:owner>
               <D:timeout>Second-604800</D:timeout>
               <D:locktoken>
                    <D:href>
               opaquelocktoken:e71d4fae-5dec-22d6-fea5-00a0c91e6be4
                    </D:href>
               </D:locktoken>
          </D:activelock>
     </D:lockdiscovery>
   </D:prop>

Multi resource lock request
---------------------------

The following LOCK request desires a lock on a collection resource with
infinite depth. The request fails, because an anchestor resource cannot be
locked. Since no lock is established, because of this failure, the
<lockdiscovery /> element is empty in the response.

::

   >>Request

   LOCK /webdav/ HTTP/1.1
   Host: webdav.sb.aol.com
   Timeout: Infinite, Second-4100000000
   Depth: infinity
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx
   Authorization: Digest username="ejw",
      realm="ejw@webdav.sb.aol.com", nonce="...",
      uri="/workspace/webdav/proposal.doc",
      response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:lockinfo xmlns:D="DAV:">
     <D:locktype><D:write/></D:locktype>
     <D:lockscope><D:exclusive/></D:lockscope>
     <D:owner>
          <D:href>http://www.ics.uci.edu/~ejw/contact.html</D:href>
     </D:owner>
   </D:lockinfo>

   >>Response

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

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
          <D:href>http://webdav.sb.aol.com/webdav/secret</D:href>
          <D:status>HTTP/1.1 403 Forbidden</D:status>
     </D:response>
     <D:response>
          <D:href>http://webdav.sb.aol.com/webdav/</D:href>
          <D:propstat>
               <D:prop><D:lockdiscovery/></D:prop>
               <D:status>HTTP/1.1 424 Failed Dependency</D:status>
          </D:propstat>
     </D:response>
   </D:multistatus>

======
UNLOCK
======

The UNLOCK operation lifts a lock from a desired resource. While a resource is
identified by the request as usual, the lock (identified by the "Lock-Token"
header) is removed from all affected reources.

Headers
=======

Lock-Token
  Uses the lock ID returned by a LOCK operation to UNLOCK the resources locked
  by this token.

XML
===

Reponse
=======

Examples
========

Simple lock removal
-------------------

This example shows a simple, successful, removal of a lock.

::

 >>Request

   UNLOCK /workspace/webdav/info.doc HTTP/1.1
   Host: webdav.sb.aol.com
   Lock-Token: <opaquelocktoken:a515cfa4-5da4-22e1-f5b5-00a0451e6bf7>
   Authorization: Digest username="ejw",
      realm="ejw@webdav.sb.aol.com", nonce="...",
      uri="/workspace/webdav/proposal.doc",
      response="...", opaque="..."

   >>Response

   HTTP/1.1 204 No Content

=======
OPTIONS
=======

The OPTIONS operation is a standard HTTP/1.1 operation, which is extended by
the "DAV" header for WebDav.

Headers
=======

DAV
  Defined the level of DAV support provided by the server for a given URI (e.g.
  1, 1#extend or 2).



..
   Local Variables:
   mode: rst
   fill-column: 79
   End: 
   vim: et syn=rst tw=79