Using POST to Add Members to Web Distributed Authoring and Versioning (WebDAV) Collections
RFC 5995

Internet Engineering Task Force (IETF)                        J. Reschke
Request for Comments: 5995                                    greenbytes
Category: Standards Track                                 September 2010
ISSN: 2070-1721

 Using POST to Add Members to Web Distributed Authoring and Versioning
                          (WebDAV) Collections

Abstract

   The Hypertext Transfer Protocol (HTTP) Extensions for the Web
   Distributed Authoring and Versioning (WebDAV) do not define the
   behavior for the "POST" method when applied to collections, as the
   base specification (HTTP) leaves implementers lots of freedom for the
   semantics of "POST".

   This has led to a situation where many WebDAV servers do not
   implement POST for collections at all, although it is well suited to
   be used for the purpose of adding new members to a collection, where
   the server remains in control of the newly assigned URL.  In fact,
   the Atom Publishing Protocol (AtomPub) uses POST exactly for that
   purpose.  On the other hand, WebDAV-based protocols, such as the
   Calendaring Extensions to WebDAV (CalDAV), frequently require clients
   to pick a unique URL, although the server could easily perform that
   task.

   This specification defines a discovery mechanism through which
   servers can advertise support for POST requests with the
   aforementioned "add collection member" semantics.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc5995.

Reschke                      Standards Track                    [Page 1]
RFC 5995            POST to Add to WebDAV Collections     September 2010

Copyright Notice

   Copyright (c) 2010 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   publication of this document.  Please review these documents
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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1. Introduction ....................................................2
   2. Terminology .....................................................4
   3. Protocol Extension ..............................................4
      3.1. Definition of "Add-Member" URI .............................5
      3.2. Discovery ..................................................6
           3.2.1. DAV:add-member Property (Protected) .................6
           3.2.2. Example .............................................6
      3.3. Relation to AtomPub's "Slug" Header Field ..................7
      3.4. Example Operation ..........................................7
   4. Additional Semantics for Existing Methods .......................8
      4.1. Additional Preconditions ...................................8
      4.2. Example: Failed PUT Request ................................8
   5. Relationship to WebDAV Access Control Protocol ..................9
   6. Internationalization Considerations .............................9
   7. Security Considerations .........................................9
   8. Acknowledgements ...............................................10
   9. References .....................................................10
      9.1. Normative References ......................................10
      9.2. Informative References ....................................11
   Index .............................................................11

1.  Introduction

   The Hypertext Transfer Protocol (HTTP) Extensions for the Web
   Distributed Authoring and Versioning (WebDAV) ([RFC4918],
   Section 9.5) do not define the behavior for the "POST" method when
   applied to collections, as the base specification (HTTP) leaves
   implementers lots of freedom for the semantics of "POST":

Reschke                      Standards Track                    [Page 2]