XEP-0164: vCard Filtering

Abstract:This document specifies a mechanism for requesting specific sections of a vCard.
Author:Daniel Henninger
Copyright:© 1999 - 2011 XMPP Standards Foundation. SEE LEGAL NOTICES.
Status:Deferred
Type:Standards Track
Version:0.1
Last Updated:2005-11-16

WARNING: Consideration of this document has been Deferred by the XMPP Standards Foundation. Implementation of the protocol described herein is not recommended.

Table of Contents


1. Introduction
2. Requirements
3. Use Cases
    3.1. Retrieving Another User's vCard Without The JABBERID Element
4. Security Considerations
5. IANA Considerations
6. XMPP Registrar Considerations
7. XML Schema

Appendices
    A: Document Information
    B: Author Information
    C: Legal Notices
    D: Relation to XMPP
    E: Discussion Venue
    F: Requirements Conformance
    G: Notes
    H: Revision History

1. Introduction

Because XML vCards (see vcard-temp [1]) are now actively used for storing avatars (see vCard-Based Avatars [2]), the ability to retrieve only portions of a vCard has become desirable. This protocol can eliminate unnecessary bandwidth usage when larger elements of a vCard are not needed.

2. Requirements

Any entity supporting this extension MUST be prepared to accept more fields than were requested, in case the target does not support this extension. A compliant target SHOULD exclude any fields listed in the filter element. In the event that the filter element does not exist or is empty, the target MUST return the entire vCard as it would without this extension.

3. Use Cases

3.1 Retrieving Another User's vCard Without The JABBERID Element

To illustrate the functionality of this protocol, we will first request a standard vCard. As shown in XEP-0054, a user may view another user's vCard by sending an IQ of type "get" to the other user's bare JID. A compliant server MUST return the vCard to the requestor and not forward the IQ to the requestee's connected resource.

Example 1. Requesting Another User's vCard

<iq to='jer@jabber.org'
    from='stpeter@jabber.org/home' 
    type='get'
    id='v1'>
  <vCard xmlns='vcard-temp'/>
</iq>

The server should then return the other user's vCard to the requestor:

Example 2. Receiving Another User's vCard

<iq from='jer@jabber.org' 
    to='stpeter@jabber.org/home' 
    type='result'
    id='v1'>
  <vCard xmlns='vcard-temp'>
    <FN>Jeremie Miller</FN>
    <N>
      <GIVEN>Jeremie</GIVEN>
      <FAMILY>Miller</FAMILY>
      <MIDDLE/>
    </N>
    <NICKNAME>jer</NICKNAME>
    <EMAIL><INTERNET/><PREF/><USERID>jeremie@jabber.org</USERID></EMAIL>
    <JABBERID>jer@jabber.org</JABBERID>
  </vCard>
</iq>

A user may request that specific portions of another user's vCard be excluded by including the requested field(s) inside a filter element qualified by the 'vcard-temp-filter' namespace, inside the vCard element.

Example 3. Requesting Another User's vCard Without the JABBERID Element

<iq to='jer@jabber.org'
    from='stpeter@jabber.org/home' 
    type='get'
    id='v2'>
  <vCard xmlns='vcard-temp'>
    <filter xmlns='vcard-temp-filter'>
       <JABBERID/>
    </filter>
  </vCard>
</iq>

The server should then return all available fields from the other user's vCard except for those listed in the filter stanza:

Example 4. Receiving Fields From Another User's vCard

<iq from='jer@jabber.org'
    to='stpeter@jabber.org/home'
    type='result'
    id='v2'>
  <vCard xmlns='vcard-temp'>
    <FN>JeremieMiller</FN>
    <N>
      <GIVEN>Jeremie</GIVEN>
      <FAMILY>Miller</FAMILY>
      <MIDDLE/>
    </N>
    <NICKNAME>jer</NICKNAME>
    <EMAIL><INTERNET/><PREF/><USERID>jeremie@jabber.org</USERID></EMAIL>
  </vCard>
</iq>

4. Security Considerations

This document introduces no new security concerns beyond those already involved in implementation and deployment of the 'vcard-temp' protocol.

5. IANA Considerations

This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [3].

6. XMPP Registrar Considerations

The XMPP Registrar [4] shall add 'vcard-temp-filter' to its registry of official namespaces.

7. XML Schema

The schema for the 'vcard-temp-filter' namespace re-uses the element names from the DTD described in XEP-0054.

<?xml version='1.0' encoding='UTF-8'?>

<xs:schema
    xmlns:xs='http://www.w3.org/2001/XMLSchema'
    targetNamespace='vcard-temp-filter'
    xmlns='vcard-temp-filter'
    elementFormDefault='qualified'>

  <xs:element name='filter'>
    <xs:complexType>
      <xs:sequence>
        <xs:element name='VERSION' type='empty'/>
        <xs:element name='FN' type='empty'/>
        <xs:element name='N' type='empty'/>
        <xs:element name='NICKNAME' type='empty'/>
        <xs:element name='PHOTO' type='empty'/>
        <xs:element name='BDAY' type='empty'/>
        <xs:element name='ADR' type='empty'/>
        <xs:element name='LABEL' type='empty'/>
        <xs:element name='TEL' type='empty'/>
        <xs:element name='EMAIL' type='empty'/>
        <xs:element name='JABBERID' type='empty'/>
        <xs:element name='MAILER' type='empty'/>
        <xs:element name='TZ' type='empty'/>
        <xs:element name='GEO' type='empty'/>
        <xs:element name='TITLE' type='empty'/>
        <xs:element name='ROLE' type='empty'/>
        <xs:element name='LOGO' type='empty'/>
        <xs:element name='AGENT' type='empty'/>
        <xs:element name='ORG' type='empty'/>
        <xs:element name='CATEGORIES' type='empty'/>
        <xs:element name='NOTE' type='empty'/>
        <xs:element name='PRODID' type='empty'/>
        <xs:element name='REV' type='empty'/>
        <xs:element name='SORT-STRING' type='empty'/>
        <xs:element name='SOUND' type='empty'/>
        <xs:element name='UID' type='empty'/>
        <xs:element name='URL' type='empty'/>
        <xs:element name='CLASS' type='empty'/>
        <xs:element name='KEY' type='empty'/>
        <xs:element name='DESC' type='empty'/>
      </xs:sequence>
    </xs:complexType>
  </xs:element>

  <xs:simpleType name='empty'>
    <xs:restriction base='xs:string'>
      <xs:enumeration value=''/>
    </xs:restriction>
  </xs:simpleType>

</xs:schema>

Appendices

Appendix A: Document Information

Series: XEP
Number: 0164
Publisher: XMPP Standards Foundation
Status: Deferred
Type: Standards Track
Version: 0.1
Last Updated: 2005-11-16
Approving Body: XMPP Council
Dependencies: XMPP Core, XEP-0054
Supersedes: None
Superseded By: None
Short Name: vcard-temp-filter
Source Control: HTML
This document in other formats: XML  PDF

Appendix B: Author Information

Daniel Henninger

Email: jadestorm@nc.rr.com
JabberID: daniel@jabber.vorpalcloud.org

Appendix C: Legal Notices

Copyright

This XMPP Extension Protocol is copyright © 1999 - 2011 by the XMPP Standards Foundation (XSF).

Permissions

Permission is hereby granted, free of charge, to any person obtaining a copy of this specification (the "Specification"), to make use of the Specification without restriction, including without limitation the rights to implement the Specification in a software program, deploy the Specification in a network service, and copy, modify, merge, publish, translate, distribute, sublicense, or sell copies of the Specification, and to permit persons to whom the Specification is furnished to do so, subject to the condition that the foregoing copyright notice and this permission notice shall be included in all copies or substantial portions of the Specification. Unless separate permission is granted, modified works that are redistributed shall not contain misleading information regarding the authors, title, number, or publisher of the Specification, and shall not claim endorsement of the modified works by the authors, any organization or project to which the authors belong, or the XMPP Standards Foundation.

Disclaimer of Warranty

## NOTE WELL: This Specification is provided on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. ##

Limitation of Liability

In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall the XMPP Standards Foundation or any author of this Specification be liable for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising from, out of, or in connection with the Specification or the implementation, deployment, or other use of the Specification (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if the XMPP Standards Foundation or such author has been advised of the possibility of such damages.

IPR Conformance

This XMPP Extension Protocol has been contributed in full conformance with the XSF's Intellectual Property Rights Policy (a copy of which can be found at <http://xmpp.org/about-xmpp/xsf/xsf-ipr-policy/> or obtained by writing to XMPP Standards Foundation, 1899 Wynkoop Street, Suite 600, Denver, CO 80202 USA).

Appendix D: Relation to XMPP

The Extensible Messaging and Presence Protocol (XMPP) is defined in the XMPP Core (RFC 3920) and XMPP IM (RFC 3921) specifications contributed by the XMPP Standards Foundation to the Internet Standards Process, which is managed by the Internet Engineering Task Force in accordance with RFC 2026. Any protocol defined in this document has been developed outside the Internet Standards Process and is to be understood as an extension to XMPP rather than as an evolution, development, or modification of XMPP itself.

Appendix E: Discussion Venue

The primary venue for discussion of XMPP Extension Protocols is the <standards@xmpp.org> discussion list.

Discussion on other xmpp.org discussion lists might also be appropriate; see <http://xmpp.org/about/discuss.shtml> for a complete list.

Errata can be sent to <editor@xmpp.org>.

Appendix F: Requirements Conformance

The following requirements keywords as used in this document are to be interpreted as described in RFC 2119: "MUST", "SHALL", "REQUIRED"; "MUST NOT", "SHALL NOT"; "SHOULD", "RECOMMENDED"; "SHOULD NOT", "NOT RECOMMENDED"; "MAY", "OPTIONAL".

Appendix G: Notes

1. XEP-0054: vcard-temp <http://xmpp.org/extensions/xep-0054.html>.

2. XEP-0153: vCard-Based Avatars <http://xmpp.org/extensions/xep-0153.html>.

3. The Internet Assigned Numbers Authority (IANA) is the central coordinator for the assignment of unique parameter values for Internet protocols, such as port numbers and URI schemes. For further information, see <http://www.iana.org/>.

4. The XMPP Registrar maintains a list of reserved protocol namespaces as well as registries of parameters used in the context of XMPP extension protocols approved by the XMPP Standards Foundation. For further information, see <http://xmpp.org/registrar/>.

Appendix H: Revision History

Note: Older versions of this specification might be available at http://xmpp.org/extensions/attic/

Version 0.1 (2005-11-16)

Initial version. (psa)

Version 0.0.2 (2005-11-05)

Switched to filter out, instead of filter in. (dah)

Version 0.0.1 (2005-10-22)

First draft. (dah)

END