WEBDAV Working Group J. Reschke, Ed. Internet-Draft S. Eissing Expires: May 26, 2006 greenbytes November 22, 2005 Including additional properties in WebDAV PROPFIND/allprop requests draft-reschke-webdav-allprop-include-07 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on May 26, 2006. Copyright Notice Copyright (C) The Internet Society (2005). Abstract Recent specifications extending the Web Distributed Authoring Protocol (WebDAV) restrict the set of properties returned automatically upon a PROPFIND/allprop request. This specification defines a method to add specific properties to the set of properties returned upon PROPFIND/allprop. Editorial Note (to be removed by RFC Editor before publication) Reschke & Eissing Expires May 26, 2006 [Page 1] Internet-Draft WebDAV PROPFIND/allprop/include November 2005 Distribution of this document is unlimited. Please send comments to the WebDAV working group at , which may be joined by sending a message with subject "subscribe" to . Discussions of the WEBDAV working group are archived at . XML and HTML versions of this draft are available from . Table of Contents 1. Notational Conventions . . . . . . . . . . . . . . . . . . . . 3 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Extensions to PROPFIND/allprop . . . . . . . . . . . . . . . . 3 3.1 Example for PROPFIND/allprop/include with extended server . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.2 Example for PROPFIND/allprop/include with non-extended server . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4. Changes to WebDAV DTD . . . . . . . . . . . . . . . . . . . . 7 5. Compatibility Considerations . . . . . . . . . . . . . . . . . 8 6. Internationalization Considerations . . . . . . . . . . . . . 8 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 8.1 Normative References . . . . . . . . . . . . . . . . . . . 8 8.2 Informative References . . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 9 A. Alternate syntax proposal from interim WebDAV working group meeting . . . . . . . . . . . . . . . . . . . . . . . . 9 A.1 PROPFIND/prop extension to include dead properties . . . . 9 A.2 Example . . . . . . . . . . . . . . . . . . . . . . . . . 10 A.3 Analysis . . . . . . . . . . . . . . . . . . . . . . . . . 11 B. Change Log (to be removed by RFC Editor before publication) . 11 B.1 Since 'draft-reschke-webdav-allprop-include-00' . . . . . 11 B.2 Since 'draft-reschke-webdav-allprop-include-01' . . . . . 12 B.3 Since 'draft-reschke-webdav-allprop-include-02' . . . . . 12 B.4 Since 'draft-reschke-webdav-allprop-include-03' . . . . . 12 B.5 Since 'draft-reschke-webdav-allprop-include-04' . . . . . 12 B.6 Since 'draft-reschke-webdav-allprop-include-05' . . . . . 12 B.7 Since 'draft-reschke-webdav-allprop-include-06' . . . . . 12 C. Open issues (to be removed by RFC Editor prior to publication) . . . . . . . . . . . . . . . . . . . . . . . . . 12 C.1 edit . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Intellectual Property and Copyright Statements . . . . . . . . 13 Reschke & Eissing Expires May 26, 2006 [Page 2] Internet-Draft WebDAV PROPFIND/allprop/include November 2005 1. Notational Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 2. Introduction Recent specifications extending the "Web Distributed Authoring Protocol" (WebDAV, [RFC2518]) like "Versioning Extensions to WebDAV" [RFC3253] and "WebDAV Access Control Protocol" [RFC3744] restrict the set of properties returned automatically upon a PROPFIND/allprop request in order to avoid the expensive computation of properties that the client in many cases isn't interested in. However, this change from the behaviour defined in WebDAV can lead to situations where clients need to perform two requests to retrieve all properties they are interested in (one using PROPFIND/allprop, then PROPFIND/prop enumerating the new properties that weren't reported upon the first request). This specification defines a backward- compatible extension to add specific properties to the set of properties returned upon PROPFIND/allprop, thus saving at least one PROPFIND request. This document defines an extension element that could ultimately become part of the core WebDAV protocol. Being just an individual submission, it currently defines it in the proprietary namespace http://sapportals.com/xmlns/cm/webdav instead of the "DAV:" namespace. It uses a prefix of "in:" for referring to elements in this namespace. However, WebDAV server and clients are free to use any prefix, provided that there is a namespace declaration that binds the prefix to the URI of the same namespace. 3. Extensions to PROPFIND/allprop The "allprop" version of PROPFIND is extended to take an optional in: include element. When present, it contains a set of property names that shall be reported in addition to those properties that the server usually would return upon PROPFIND/allprop. Reschke & Eissing Expires May 26, 2006 [Page 3] Internet-Draft WebDAV PROPFIND/allprop/include November 2005 3.1 Example for PROPFIND/allprop/include with extended server >>Request PROPFIND /container/front.html HTTP/1.1 Host: www.example.org Depth: 1 Content-Type: text/xml; charset="utf-8" Content-Length: xxxx >>Response Reschke & Eissing Expires May 26, 2006 [Page 4] Internet-Draft WebDAV PROPFIND/allprop/include November 2005 HTTP/1.1 207 Multi-Status Content-Type: text/xml; charset="utf-8" Content-Length: xxxx http://www.example.org/container/front.html Box type B 1997-12-01T18:27:21-08:00 Example HTML resource 4525 text/html zzyzx Monday, 12-Jan-98 09:25:56 GMT http://www.example.org/vsn/container/front.html-1 HTTP/1.1 200 OK HTTP/1.1 404 NOT FOUND In this example, the server has recognized the extension element in: Reschke & Eissing Expires May 26, 2006 [Page 5] Internet-Draft WebDAV PROPFIND/allprop/include November 2005 include and included the properties DAV:checked-in and DAV:checked- out (as defined in [RFC3253]). 3.2 Example for PROPFIND/allprop/include with non-extended server >>Request PROPFIND /container/front.html HTTP/1.1 Host: www.example.org Depth: 1 Content-Type: text/xml; charset="utf-8" Content-Length: xxxx Reschke & Eissing Expires May 26, 2006 [Page 6] Internet-Draft WebDAV PROPFIND/allprop/include November 2005 >>Response HTTP/1.1 207 Multi-Status Content-Type: text/xml; charset="utf-8" Content-Length: xxxx http://www.example.org/container/front.html Box type B 1997-12-01T18:27:21-08:00 Example HTML resource 4525 text/html zzyzx Monday, 12-Jan-98 09:25:56 GMT HTTP/1.1 200 OK In this case the in:include element was simply ignored. The client can detect this situation by checking for the presence of the requested properties and will have to issue an additional PROPFIND/ prop request (to retrieve the missing properties). 4. Changes to WebDAV DTD Reschke & Eissing Expires May 26, 2006 [Page 7] Internet-Draft WebDAV PROPFIND/allprop/include November 2005 Note that the WebDAV DTD is informal only and cannot be used to validate request or response bodies (due to the inability to properly work with XML namespaces). 5. Compatibility Considerations This specification introduces a new child element for the DAV: propfind element, defined in Section 4. Old servers will ignore this element (see [RFC2518], chapter 14). Clients can detect this situation as outlined in Section 3.2. Clients not aware of this specification will not be affected at all, because they will never use the new in:include element in PROPFIND requests. 6. Internationalization Considerations This proposal builds on [RFC2518], and inherits its internationalizability. 7. IANA Considerations This proposal does not introduce any new IANA considerations, since it does not specify any new namespaces (in the general sense), but merely uses existing ones. 8. References 8.1 Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2518] Goland, Y., Whitehead, E., Faizi, A., Carter, S., and D. Jensen, "HTTP Extensions for Distributed Authoring -- WEBDAV", RFC 2518, February 1999. [RFC3253] Clemm, G., Amsden, J., Ellison, T., Kaler, C., and J. Whitehead, "Versioning Extensions to WebDAV", RFC 3253, March 2002. 8.2 Informative References [RFC3744] Clemm, G., Reschke, J., Sedlar, E., and J. Whitehead, "Web Distributed Authoring and Versioning (WebDAV) Access Control Protocol", RFC 3744, May 2004. [draft-ietf-webdav-rfc2518bis] Reschke & Eissing Expires May 26, 2006 [Page 8] Internet-Draft WebDAV PROPFIND/allprop/include November 2005 Dusseault, L. and J. Crawford, "HTTP Extensions for Distributed Authoring - WebDAV RFC2518 bis", draft-ietf-webdav-rfc2518bis-08 (work in progress), November 2005, . Authors' Addresses Julian F. Reschke (editor) greenbytes GmbH Hafenweg 16 Muenster, NW 48155 Germany Phone: +49 251 2807760 Fax: +49 251 2807761 Email: julian.reschke@greenbytes.de URI: http://greenbytes.de/tech/webdav/ Stefan Eissing greenbytes GmbH Hafenweg 16 Muenster, NW 48155 Germany Phone: +49 251 2807760 Fax: +49 251 2807761 Email: stefan.eissing@greenbytes.de URI: http://greenbytes.de/tech/webdav/ Appendix A. Alternate syntax proposal from interim WebDAV working group meeting This section briefly describes an alternate approach to the problem covered by this draft. It was discussed during the interim WebDAV working group meeting in January 2003 and was supported by all meeting attendees. It was also added to the draft for the revision of [RFC2518], [draft-ietf-webdav-rfc2518bis]. A.1 PROPFIND/prop extension to include dead properties Additional PROPFIND marshalling: Reschke & Eissing Expires May 26, 2006 [Page 9] Internet-Draft WebDAV PROPFIND/allprop/include November 2005 The DAV:dead-props element can be added to PROPFIND requests that retrieve named properties using DAV:prop. When present, the server MUST include all dead properties defined on the resource. A.2 Example This example shows the alternate syntax applied to the example from Section 3.1. >>Request PROPFIND /container/front.html HTTP/1.1 Host: www.example.org Depth: 1 Content-Type: text/xml; charset="utf-8" Content-Length: xxxx Reschke & Eissing Expires May 26, 2006 [Page 10] Internet-Draft WebDAV PROPFIND/allprop/include November 2005 >>Response HTTP/1.1 207 Multi-Status Content-Type: text/xml; charset="utf-8" Content-Length: xxxx http://www.example.org/container/front.html Box type B http://www.example.org/vsn/container/front.html-1 HTTP/1.1 200 OK HTTP/1.1 404 NOT FOUND A.3 Analysis At first glance, this extension seems to have equivalent semantics. On closer inspection, it doesn't provide the client any means to actually find out whether the remote server understood the extension (it can't distinguish between "server does not now about "dead- props", and "there are no dead properties on the resource"). Appendix B. Change Log (to be removed by RFC Editor before publication) B.1 Since 'draft-reschke-webdav-allprop-include-00' Moved element out of "DAV:" namespace. Updated reference to deltaV (now RFC3253). Changed examples to explicitly use utf-8 encoding for HTTP content type and XML encoding. Reschke & Eissing Expires May 26, 2006 [Page 11] Internet-Draft WebDAV PROPFIND/allprop/include November 2005 Updated WebDAV ACL reference to draft 07. Made sure figures fit in 72 columns. Split references into "Normative" and "Informative". B.2 Since 'draft-reschke-webdav-allprop-include-01' Updated WebDAV ACL reference to draft 09. B.3 Since 'draft-reschke-webdav-allprop-include-02' Fixed XML errors in examples (wrong closing href tags). Replaced domain names in examples according to RFC2606: "www.foo.bar" by "www.example.org". Shortened checked-in URI to fit into 72 characters in example. B.4 Since 'draft-reschke-webdav-allprop-include-03' Added short description of alternate syntax discussed during interim WebDAV WG meeting (January 2003). B.5 Since 'draft-reschke-webdav-allprop-include-04' DTD fix for dead-props variant. Remove superfluous IP and copyright sections. Added reference to RFC2518bis. Updated reference to ACL draft. B.6 Since 'draft-reschke-webdav-allprop-include-05' Updated various references. Update abstract. B.7 Since 'draft-reschke-webdav-allprop-include-06' Updated RFC2518bis reference. Author's address updated. Added analysis of shortcomings of the RFC2518bis approach. Appendix C. Open issues (to be removed by RFC Editor prior to publication) C.1 edit Type: edit julian.reschke@greenbytes.de (2005-01-01): Umbrella issue for editorial fixes/enhancements. Reschke & Eissing Expires May 26, 2006 [Page 12] Internet-Draft WebDAV PROPFIND/allprop/include November 2005 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. 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Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Reschke & Eissing Expires May 26, 2006 [Page 13]