7Network Working Group                                           C. Daboo
 
8Request for Comments: 5689                                    Apple Inc.
 
9Updates: 4791, 4918                                       September 2009
 
10Category: Standards Track
 
13  Extended MKCOL for Web Distributed Authoring and Versioning (WebDAV)
 
17   This specification extends the Web Distributed Authoring and
 
18   Versioning (WebDAV) MKCOL (Make Collection) method to allow
 
19   collections of arbitrary resourcetype to be created and to allow
 
20   properties to be set at the same time.
 
24   This document specifies an Internet standards track protocol for the
 
25   Internet community, and requests discussion and suggestions for
 
26   improvements.  Please refer to the current edition of the "Internet
 
27   Official Protocol Standards" (STD 1) for the standardization state
 
28   and status of this protocol.  Distribution of this memo is unlimited.
 
32   Copyright (c) 2009 IETF Trust and the persons identified as the
 
33   document authors.  All rights reserved.
 
35   This document is subject to BCP 78 and the IETF Trust's Legal
 
36   Provisions Relating to IETF Documents
 
37   (http://trustee.ietf.org/license-info) in effect on the date of
 
38   publication of this document.  Please review these documents
 
39   carefully, as they describe your rights and restrictions with respect
 
40   to this document.  Code Components extracted from this document must
 
41   include Simplified BSD License text as described in Section 4.e of
 
42   the Trust Legal Provisions and are provided without warranty as
 
43   described in the BSD License.
 
45   This document may contain material from IETF Documents or IETF
 
46   Contributions published or made publicly available before November
 
47   10, 2008.  The person(s) controlling the copyright in some of this
 
48   material may not have granted the IETF Trust the right to allow
 
49   modifications of such material outside the IETF Standards Process.
 
50   Without obtaining an adequate license from the person(s) controlling
 
51   the copyright in such materials, this document may not be modified
 
52   outside the IETF Standards Process, and derivative works of it may
 
58Daboo                       Standards Track                     [Page 1]
 
60RFC 5689               Extended MKCOL for WebDAV          September 2009
 
63   not be created outside the IETF Standards Process, except to format
 
64   it for publication as an RFC or to translate it into languages other
 
69   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
 
70   2.  Conventions Used in This Document  . . . . . . . . . . . . . .  3
 
71   3.  WebDAV Extended MKCOL  . . . . . . . . . . . . . . . . . . . .  4
 
72     3.1.  Extended MKCOL Support . . . . . . . . . . . . . . . . . .  5
 
73       3.1.1.  Example: Using OPTIONS for the Discovery of
 
74               Support for Extended MKCOL . . . . . . . . . . . . . .  5
 
75     3.2.  Status Codes . . . . . . . . . . . . . . . . . . . . . . .  5
 
76     3.3.  Additional Precondition for Extended MKCOL . . . . . . . .  5
 
77     3.4.  Example: Successful Extended MKCOL Request . . . . . . . .  6
 
78     3.5.  Example: Unsuccessful Extended MKCOL Request . . . . . . .  6
 
79   4.  Using Extended MKCOL as an Alternative for MKxxx Methods . . .  8
 
80     4.1.  MKCALENDAR Alternative . . . . . . . . . . . . . . . . . .  8
 
81       4.1.1.  Example: Using MKCOL Instead of MKCALENDAR . . . . . .  8
 
82   5.  XML Element Definitions  . . . . . . . . . . . . . . . . . . . 10
 
83     5.1.  mkcol XML Element  . . . . . . . . . . . . . . . . . . . . 10
 
84     5.2.  mkcol-response XML Element . . . . . . . . . . . . . . . . 10
 
85   6.  Security Considerations  . . . . . . . . . . . . . . . . . . . 11
 
86   7.  Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 11
 
87   8.  Normative References . . . . . . . . . . . . . . . . . . . . . 11
 
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116RFC 5689               Extended MKCOL for WebDAV          September 2009
 
121   WebDAV [RFC4918] defines the HTTP [RFC2616] method MKCOL.  This
 
122   method is used to create WebDAV collections on the server.  However,
 
123   several WebDAV-based specifications (e.g., CalDAV [RFC4791]) define
 
124   "special" collections -- ones that are identified by additional
 
125   values in the DAV:resourcetype property assigned to the collection
 
126   resource or by other means.  These "special" collections are created
 
127   by new methods (e.g., MKCALENDAR).  The addition of a new MKxxx
 
128   method for each new "special" collection adds to server complexity
 
129   and is detrimental to overall reliability due to the need to make
 
130   sure intermediaries are aware of these methods.
 
132   This specification defines an extension to the WebDAV MKCOL method
 
133   that adds a request body allowing a client to specify WebDAV
 
134   properties to be set on the newly created collection or resource.  In
 
135   particular, the DAV:resourcetype property can be used to create a
 
136   "special" collection; alternatively, other properties can be used to
 
137   create a "special" resource.  This avoids the need to invent new
 
1402.  Conventions Used in This Document
 
142   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
 
143   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
 
144   document are to be interpreted as described in [RFC2119].
 
146   This document uses XML DTD fragments (Section 3.2 of
 
147   [W3C.REC-xml-20081126]) as a purely notational convention.  WebDAV
 
148   request and response bodies cannot be validated by a DTD due to the
 
149   specific extensibility rules defined in Section 17 of [RFC4918] and
 
150   due to the fact that all XML elements defined by this specification
 
151   use the XML namespace name "DAV:".  In particular:
 
153   1.  Element names use the "DAV:" namespace.
 
155   2.  Element ordering is irrelevant unless explicitly stated.
 
157   3.  Extension elements (elements not already defined as valid child
 
158       elements) may be added anywhere, except when explicitly stated
 
161   4.  Extension attributes (attributes not already defined as valid for
 
162       this element) may be added anywhere, except when explicitly
 
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172RFC 5689               Extended MKCOL for WebDAV          September 2009
 
175   When an XML element type in the "DAV:" namespace is referenced in
 
176   this document outside of the context of an XML fragment, the string
 
177   "DAV:" will be prefixed to the element type.
 
179   This document inherits, and sometimes extends, DTD productions from
 
180   Section 14 of [RFC4918].
 
1823.  WebDAV Extended MKCOL
 
184   The WebDAV MKCOL request is extended to allow the inclusion of a
 
185   request body.  The request body is an XML document containing a
 
186   single DAV:mkcol XML element as the root element.  The Content-Type
 
187   request header MUST be set appropriately for an XML body (e.g., set
 
188   to "text/xml" or "application/xml").  XML-typed bodies for an MKCOL
 
189   request that do not have DAV:mkcol as the root element are reserved
 
192   One or more DAV:set XML elements may be included in the DAV:mkcol XML
 
193   element to allow setting properties on the collection as it is
 
194   created.  In particular, to create a collection of a particular type,
 
195   the DAV:resourcetype XML element MUST be included in a DAV:set XML
 
196   element and MUST specify the expected resource type elements for the
 
197   new resource, which MUST include the DAV:collection element that
 
198   needs to be present for any WebDAV collection.
 
200   As per the PROPPATCH method (Section 9.2 of [RFC4918]), servers MUST
 
201   process any DAV:set instructions in document order (an exception to
 
202   the normal rule that ordering is irrelevant).  If any one instruction
 
203   fails to execute successfully, all instructions MUST fail (i.e.,
 
204   either all succeed or all fail).  Thus, if any error occurs during
 
205   processing, all executed instructions MUST be undone and a proper
 
206   error result returned.  Failure to set a property value on the
 
207   collection MUST result in a failure of the overall MKCOL request --
 
208   i.e., the collection is not created.
 
210   The response to an extended MKCOL request MUST be an XML document
 
211   containing a single DAV:mkcol-response XML element, which MUST
 
212   contain DAV:propstat XML elements with the status of each property
 
213   when the request fails due to a failure to set one or more of the
 
214   properties specified in the request body.  The server MAY return a
 
215   response body in the case where the request is successful, indicating
 
216   success for setting each property specified in the request body.
 
217   When an empty response body is returned with a success request status
 
218   code, the client can assume that all properties were set.
 
220   In all other respects, the behavior of the extended MKCOL request
 
221   follows that of the standard MKCOL request.
 
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228RFC 5689               Extended MKCOL for WebDAV          September 2009
 
2313.1.  Extended MKCOL Support
 
233   A server supporting the features described in this document MUST
 
234   include "extended-mkcol" as a field in the DAV response header from
 
235   an OPTIONS request on any URI that supports use of the extended MKCOL
 
2383.1.1.  Example: Using OPTIONS for the Discovery of Support for Extended
 
243   OPTIONS /addressbooks/users/ HTTP/1.1
 
244   Host: addressbook.example.com
 
249   Allow: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE
 
250   Allow: MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, REPORT, ACL
 
251   DAV: 1, 2, 3, access-control, extended-mkcol
 
252   Date: Sat, 11 Nov 2006 09:32:12 GMT
 
257   As per Section 9.3.1 of [RFC4918].
 
2593.3.  Additional Precondition for Extended MKCOL
 
261   WebDAV ([RFC4918], Section 16) defines preconditions and
 
262   postconditions for request behavior.  This specification adds the
 
263   following precondition for the extended MKCOL request.
 
265   Name:  valid-resourcetype
 
269   Use with:  Typically 403 (Forbidden)
 
271   Purpose:  (precondition) -- The server MUST support the specified
 
272      resourcetype value for the specified collection.
 
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284RFC 5689               Extended MKCOL for WebDAV          September 2009
 
2873.4.  Example: Successful Extended MKCOL Request
 
289   This example shows how the extended MKCOL request is used to create a
 
290   collection of a fictitious type "special-resource".  The response
 
291   body is empty as the request completed successfully.
 
295   MKCOL /home/special/ HTTP/1.1
 
296   Host: special.example.com
 
297   Content-Type: application/xml; charset="utf-8"
 
300   <?xml version="1.0" encoding="utf-8" ?>
 
301   <D:mkcol xmlns:D="DAV:"
 
302                 xmlns:E="http://example.com/ns/">
 
307           <E:special-resource/>
 
309         <D:displayname>Special Resource</D:displayname>
 
317   Cache-Control: no-cache
 
318   Date: Sat, 11 Nov 2006 09:32:12 GMT
 
3203.5.  Example: Unsuccessful Extended MKCOL Request
 
322   This example shows an attempt to use the extended MKCOL request to
 
323   create a collection of a fictitious type "special-resource", which is
 
324   not actually supported by the server.  The response body shows that
 
325   an error occurred specifically with the DAV:resourcetype property.
 
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340RFC 5689               Extended MKCOL for WebDAV          September 2009
 
345   MKCOL /home/special/ HTTP/1.1
 
346   Host: special.example.com
 
347   Content-Type: application/xml; charset="utf-8"
 
350   <?xml version="1.0" encoding="utf-8" ?>
 
351   <D:mkcol xmlns:D="DAV:"
 
352                 xmlns:E="http://example.com/ns/">
 
357           <E:special-resource/>
 
359         <D:displayname>Special Resource</D:displayname>
 
366   HTTP/1.1 403 Forbidden
 
367   Cache-Control: no-cache
 
368   Date: Sat, 11 Nov 2006 09:32:12 GMT
 
369   Content-Type: application/xml; charset="utf-8"
 
372   <?xml version="1.0" encoding="utf-8" ?>
 
373   <D:mkcol-response xmlns:D="DAV:">
 
378       <D:status>HTTP/1.1 403 Forbidden</D:status>
 
379       <D:error><D:valid-resourcetype /></D:error>
 
380       <D:responsedescription>Resource type is not
 
381       supported by this server</D:responsedescription>
 
387       <D:status>HTTP/1.1 424 Failed Dependency</D:status>
 
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396RFC 5689               Extended MKCOL for WebDAV          September 2009
 
3994.  Using Extended MKCOL as an Alternative for MKxxx Methods
 
401   One of the goals of this extension is to eliminate the need for other
 
402   extensions to define their own variant of MKCOL to create the special
 
403   collections they need.  This extension can be used as an alternative
 
404   to existing MKxxx methods in other extensions as detailed below.  If
 
405   a server supports this extension and the other extension listed, then
 
406   the server MUST support use of the extended MKCOL method to achieve
 
407   the same result as the MKxxx method of the other extension.
 
4094.1.  MKCALENDAR Alternative
 
411   CalDAV defines the MKCALENDAR method to create a calendar collection
 
412   as well as to set properties during creation (Section 5.3.1 of
 
415   The extended MKCOL method can be used instead by specifying both DAV:
 
416   collection and CALDAV:calendar-collection XML elements in the DAV:
 
417   resourcetype property, set during the extended MKCOL request.
 
4194.1.1.  Example: Using MKCOL Instead of MKCALENDAR
 
421   The first example below shows an MKCALENDAR request containing a
 
422   CALDAV:mkcalendar XML element in the request body and returning a
 
423   CALDAV:mkcalendar-response XML element in the response body.
 
425   >> MKCALENDAR Request <<
 
427   MKCALENDAR /home/lisa/calendars/events/ HTTP/1.1
 
428   Host: calendar.example.com
 
429   Content-Type: application/xml; charset="utf-8"
 
432   <?xml version="1.0" encoding="utf-8" ?>
 
433   <C:mkcalendar xmlns:D="DAV:"
 
434                 xmlns:C="urn:ietf:params:xml:ns:caldav">
 
437         <D:displayname>Lisa's Events</D:displayname>
 
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452RFC 5689               Extended MKCOL for WebDAV          September 2009
 
455   >> MKCALENDAR Response <<
 
458   Cache-Control: no-cache
 
459   Date: Sat, 11 Nov 2006 09:32:12 GMT
 
460   Content-Type: application/xml; charset="utf-8"
 
463   <?xml version="1.0" encoding="utf-8" ?>
 
464   <C:mkcalendar-response xmlns:D="DAV:"
 
465                 xmlns:C="urn:ietf:params:xml:ns:caldav">
 
470       <D:status>HTTP/1.1 200 OK</D:status>
 
472   </C:mkcalendar-response>
 
474   The second example shows the equivalent extended MKCOL request with
 
475   the same request and response XML elements.
 
479   MKCOL /home/lisa/calendars/events/ HTTP/1.1
 
480   Host: calendar.example.com
 
481   Content-Type: application/xml; charset="utf-8"
 
484   <?xml version="1.0" encoding="utf-8" ?>
 
485   <D:mkcol xmlns:D="DAV:"
 
486                 xmlns:C="urn:ietf:params:xml:ns:caldav">
 
493         <D:displayname>Lisa's Events</D:displayname>
 
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508RFC 5689               Extended MKCOL for WebDAV          September 2009
 
514   Cache-Control: no-cache
 
515   Date: Sat, 11 Nov 2006 09:32:12 GMT
 
516   Content-Type: application/xml; charset="utf-8"
 
519   <?xml version="1.0" encoding="utf-8" ?>
 
520   <D:mkcol-response xmlns:D="DAV:"
 
521                 xmlns:C="urn:ietf:params:xml:ns:caldav">
 
527       <D:status>HTTP/1.1 200 OK</D:status>
 
5315.  XML Element Definitions
 
5335.1.  mkcol XML Element
 
539   Purpose:  Used in a request to specify properties to be set in an
 
540      extended MKCOL request, as well as any additional information
 
541      needed when creating the resource.
 
543   Description:  This XML element is a container for the information
 
544      required to modify the properties on a collection resource as it
 
545      is created in an extended MKCOL request.
 
549       <!ELEMENT mkcol (set+)>
 
5515.2.  mkcol-response XML Element
 
562Daboo                       Standards Track                    [Page 10]
 
564RFC 5689               Extended MKCOL for WebDAV          September 2009
 
567   Purpose:  Used in a response to indicate the status of properties
 
568      that were set or failed to be set during an extended MKCOL
 
571   Description:  This XML element is a container for the information
 
572      returned about a resource that has been created in an extended
 
577       <!ELEMENT mkcol-response (propstat+)>
 
5796.  Security Considerations
 
581   This extension does not introduce any new security concerns beyond
 
582   those already described in HTTP [RFC2616] and WebDAV [RFC4918].
 
586   Thanks to Bernard Desruisseaux, Mike Douglass, Alexey Melnikov,
 
587   Julian Reschke, and Simon Vaillancourt.
 
5908.  Normative References
 
592   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
 
593              Requirement Levels", BCP 14, RFC 2119, March 1997.
 
595   [RFC2616]  Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
 
596              Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
 
597              Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
 
599   [RFC4791]  Daboo, C., Desruisseaux, B., and L. Dusseault,
 
600              "Calendaring Extensions to WebDAV (CalDAV)", RFC 4791,
 
603   [RFC4918]  Dusseault, L., "HTTP Extensions for Web Distributed
 
604              Authoring and Versioning (WebDAV)", RFC 4918, June 2007.
 
606   [W3C.REC-xml-20081126]
 
607              Maler, E., Yergeau, F., Paoli, J., Bray, T., and C.
 
608              Sperberg-McQueen, "Extensible Markup Language (XML) 1.0
 
609              (Fifth Edition)", World Wide Web Consortium
 
610              Recommendation REC-xml-20081126, November 2008,
 
611              <http://www.w3.org/TR/2008/REC-xml-20081126>.
 
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620RFC 5689               Extended MKCOL for WebDAV          September 2009
 
631   EMail: cyrus@daboo.name
 
632   URI:   http://www.apple.com/
 
674Daboo                       Standards Track                    [Page 12]