XEP-0048: Bookmarks

Abstract:This specification defines an XML data format for use by XMPP clients in storing bookmarks to mult-user chatrooms and web pages. The chatroom bookmarking function includes the ability to auto-join rooms on login.
Authors:Rachel Blackman, Peter Millard, Peter Saint-Andre
Copyright:© 1999 - 2014 XMPP Standards Foundation. SEE LEGAL NOTICES.
Status:Draft
Type:Standards Track
Version:1.1
Last Updated:2007-11-07

NOTICE: The protocol defined herein is a Draft Standard of the XMPP Standards Foundation. Implementations are encouraged and the protocol is appropriate for deployment in production systems, but some changes to the protocol are possible before it becomes a Final Standard.


Table of Contents


1. Introduction
2. Data Format
    2.1. The conference element
    2.2. The url element
3. Storage
    3.1. Uploading Data
    3.2. Receiving Notifications
    3.3. Retrieving Data
4. Security Considerations
5. IANA Considerations
6. XMPP Registrar Considerations
7. XML Schema
8. Author Note

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

For ease-of-use in a Jabber client, it is desirable to have a way to store shortcuts to various services and resources (such as conference rooms and web pages) as "bookmarks" that can be displayed in the user's client. Several Jabber clients have already agreed on and implemented a method to provide this service; that informal agreement is documented and expanded upon in this document. In particular, we introduce the <storage/> element (qualified by the 'storage:bookmarks' namespace) as a container for this sort of this data. While bookmarks data can be stored using any XML storage mechanism, this document recommends one method that is specific to XMPP.

2. Data Format

A storage element qualified by the 'storage:bookmarks' namespace may contain a collection of child elements, each representing a bookmark to be displayed in a client. At present, only two sub-elements are defined: <conference/> for bookmarking of Multi-User Chat (XEP-0045) [1] rooms and <url/> for bookmarking of web pages.

All child elements allow a 'name' attribute, which is the friendly name by which they will be displayed in the client. If an element lacks a 'name' attribute, the client SHOULD generate an appropriate substitution based on the other available data.

2.1 The conference element

A common use case is bookmarking of multi-user chat rooms. A room is bookmarked using the <conference/> child element. The syntax is as follows.

Table 1: Syntax of conference element

Element or Attribute Definition Datatype Inclusion
'autojoin' attribute Whether the client should automatically join the conference room on login. boolean defaulting to false [2] OPTIONAL
'jid' attribute The JabberID of the chat room. string REQUIRED
'name' attribute A friendly name for the bookmark. string RECOMMENDED
<nick/> element The user's preferred roomnick for the chatroom. string OPTIONAL
<password/> element Unencrypted string for the password needed to enter a password-protected room. For security reasons, use of this element is NOT RECOMMENDED. string NOT RECOMMENDED

Note: The datatypes are as defined in XML Schema Part 2 [3].

Example 1. An example of the conference element

    <storage xmlns='storage:bookmarks'>
      <conference name='Council of Oberon' 
                  autojoin='true'
                  jid='council@conference.underhill.org'>
        <nick>Puck</nick>
      </conference>
    </storage>
    

This bookmark would be displayed as 'Council of Oberon' and, if activated, would attempt to join the conference room 'council@conference.underhill.org' with nickname 'Puck'.

Note: A bookmark set may contain any number of conference rooms.

2.2 The url element

The <url/> element is designed for bookmarking web pages, i.e., HTTP or HTTPS URLs. The syntax is as follows.

Table 2: Syntax of url element

Attribute Definition Datatype Inclusion
'name' attribute A friendly name for the bookmark. string RECOMMENDED
'url' attribute The HTTP or HTTPS URL of the web page. anyURI REQUIRED

When the user chooses a URL bookmark, the client should launch an appropriate browser or load the URL directly in the client (if the client is a web-client or includes web browsing functionality).

Example 2. An example of the url element

    <storage xmlns='storage:bookmarks'>
      <url name='Complete Works of Shakespeare'
           url='http://the-tech.mit.edu/Shakespeare/'/>
    </storage>
    

This bookmark would be displayed in the client as 'Complete Works of Shakespeare' and would take the user to <http://the-tech.mit.edu/Shakespeare/> when selected.

Note: A bookmark set can contain any number of URLs.

3. Storage

It is RECOMMENDED to use Publish-Subscribe (XEP-0060) [4] for data storage, specifically through the use of personal data nodes hosted at the user's virtual publish-subscribe service as described in Best Practices for Persistent Storage of Private Data via Publish-Subscribe (XEP-0223) [5] and illustrated in the following sections.

Note: In the past, Private XML Storage (XEP-0049) [6] was the recommended method (see the archived version of this specification at <http://www.xmpp.org/extensions/attic/xep-0048-1.0.html>). In addition, other methods could be used, such as HTTP or WebDAV.

3.1 Uploading Data

Example 3. Client uploads data

<iq from='juliet@capulet.lit/balcony' type='set' id='pip1'>
  <pubsub xmlns='http://jabber.org/protocol/pubsub'>
    <publish node='storage:bookmarks'>
      <item id='current'>
        <storage xmlns='storage:bookmarks'>
          <conference name='The Play&apos;s the Thing' 
                      autojoin='true'
                      jid='theplay@conference.shakespeare.lit'>
            <nick>JC</nick>
          </conference>
        </storage>
      </item>
    </publish>
    <publish-options>
      <x xmlns='jabber:x:data' type='submit'>
        <field var='FORM_TYPE' type='hidden'>
          <value>http://jabber.org/protocol/pubsub#publish-options</value>
        </field>
        <field var='pubsub#persist_items'>
          <value>true</value>
        </field>
        <field var='pubsub#access_model'>
          <value>whitelist</value>
        </field>
      </x>
    </publish-options>
  </pubsub>
</iq>
    

Example 4. Server acknowledges successful storage

<iq to='juliet@capulet.lit/balcony' type='result' id='pip1'/>
    

3.2 Receiving Notifications

The stored data is automatically pushed to all of the user's connected resources.

Example 5. Publisher receives event notification

<message from='juliet@capulet.lit'
         to='juliet@capulet.lit/balcony'
         type='headline'
         id='rnfoo1'>
  <event xmlns='http://jabber.org/protocol/pubsub#event'>
    <items node='storage:bookmarks'>
      <item id='current'>
        <storage xmlns='storage:bookmarks'>
          <conference name='The Play&apos;s the Thing' 
                      autojoin='true'
                      jid='theplay@conference.shakespeare.lit'>
            <nick>JC</nick>
          </conference>
        </storage>
      </item>
    </items>
  </event>
</message>

<message from='juliet@capulet.lit'
         to='juliet@capulet.lit/chamber'
         type='headline'
         id='rnfoo2'>
  <event xmlns='http://jabber.org/protocol/pubsub#event'>
    <items node='storage:bookmarks'>
      <item id='current'>
        <storage xmlns='storage:bookmarks'>
          <conference name='The Play&apos;s the Thing' 
                      autojoin='true'
                      jid='theplay@conference.shakespeare.lit'>
            <nick>JC</nick>
          </conference>
        </storage>
      </item>
    </items>
  </event>
</message>
    

3.3 Retrieving Data

In order to retrieve stored data without receiving notifications (e.g., upon initial login), the user's client sends a retrieve-items request as specified in XEP-0060.

Example 6. Client requests all items

<iq from='juliet@capulet.lit/randomID' type='get' id='retrieve1'>
  <pubsub xmlns='http://jabber.org/protocol/pubsub'>
    <items node='storage:bookmarks'/>
  </pubsub>
</iq>
    

Example 7. Server returns all items

<iq type='result'
    to='juliet@capulet.lit/randomID'
    id='retrieve1'>
  <pubsub xmlns='http://jabber.org/protocol/pubsub'>
    <items node='storage:bookmarks'>
      <item id='current'>
        <storage xmlns='storage:bookmarks'>
          <conference name='The Play&apos;s the Thing' 
                      autojoin='true'
                      jid='theplay@conference.shakespeare.lit'>
            <nick>JC</nick>
          </conference>
        </storage>
      </item>
    </items>
  </pubsub>
</iq>
    

4. Security Considerations

Security considerations related to object persistent via publish-subscribe are described in XEP-0060 and XEP-0223.

Use of the <password/> child of the <conference/> element is NOT RECOMMENDED, since the password could be discovered by a third party, e.g. an eavesdropper (if channel encryption is not used) or a server administrator. However, the element MAY be used in suitably secure environments (e.g., where it is known that communications will not be sent over unencrypted channels and the server administrators are trusted). Clients SHOULD NOT default to storing passwords and MUST enable users to disable any password storage.

5. IANA Considerations

This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [7].

6. XMPP Registrar Considerations

No action by the XMPP Registrar [8] is required, since the 'storage:bookmarks' namespace is already included in the protocol namespaces registry (see <http://xmpp.org/registrar/namespaces.html>).

7. XML Schema

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

<xs:schema
    xmlns:xs='http://www.w3.org/2001/XMLSchema'
    targetNamespace='storage:bookmarks'
    xmlns='storage:bookmarks'
    elementFormDefault='qualified'>

  <xs:annotation>
    <xs:documentation>
      The protocol documented by this schema is defined in
      XEP-0048: http://www.xmpp.org/extensions/xep-0048.html
    </xs:documentation>
  </xs:annotation>

  <xs:element name='storage'>
    <xs:complexType>
      <xs:choice>
        <xs:element ref='conference'/>
        <xs:element ref='url'/>
      </xs:choice>
    </xs:complexType>
  </xs:element>

  <xs:element name='conference'>
    <xs:complexType>
      <xs:sequence>
        <xs:element name='nick' type='xs:string' minOccurs='0'/>
        <xs:element name='password' type='xs:string' minOccurs='0'/>
      </xs:sequence>
      <xs:attribute name='autojoin' type='xs:boolean' use='optional' default='false'/>
      <xs:attribute name='jid' type='xs:string' use='required'/>
      <xs:attribute name='name' type='xs:string' use='required'/>
    </xs:complexType>
  </xs:element>

  <xs:element name='url'>
    <xs:complexType>
      <xs:simpleContent>
        <xs:extension base='empty'>
          <xs:attribute name='name' type='xs:string' use='required'/>
          <xs:attribute name='url' type='xs:string' use='required'/>
        </xs:extension>
      </xs:simpleContent>
    </xs:complexType>
  </xs:element>

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

</xs:schema>
  

8. Author Note

Peter Millard, a co-author of this specification from version 0.1 through version 1.0, died on April 26, 2006.


Appendices


Appendix A: Document Information

Series: XEP
Number: 0048
Publisher: XMPP Standards Foundation
Status: Draft
Type: Standards Track
Version: 1.1
Last Updated: 2007-11-07
Approving Body: XMPP Council
Dependencies: XMPP Core, XEP-0060, XEP-0223
Supersedes: None
Superseded By: None
Short Name: bookmarks
Schema: <http://www.xmpp.org/schemas/bookmarks.xsd>
Source Control: HTML
This document in other formats: XML  PDF


Appendix B: Author Information

Rachel Blackman

Email: rcb@ceruleanstudios.com
JabberID: sparks@jabber.org

Peter Millard

See Author Note

Peter Saint-Andre

Email: stpeter@jabber.org
JabberID: stpeter@jabber.org
URI: https://stpeter.im/


Appendix C: Legal Notices

Copyright

This XMPP Extension Protocol is copyright © 1999 - 2014 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 6120) and XMPP IM (RFC 6121) 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-0045: Multi-User Chat <http://xmpp.org/extensions/xep-0045.html>.

2. In accordance with Section 3.2.2.1 of XML Schema Part 2: Datatypes, the allowable lexical representations for the xs:boolean datatype are the strings "0" and "false" for the concept 'false' and the strings "1" and "true" for the concept 'true'; implementations MUST support both styles of lexical representation.

3. XML Schema Part 2: Datatypes <http://www.w3.org/TR/xmlschema-2/>.

4. XEP-0060: Publish-Subscribe <http://xmpp.org/extensions/xep-0060.html>.

5. XEP-0223: Best Practices for Persistent Storage of Private Data via Publish-Subscribe <http://xmpp.org/extensions/xep-0223.html>.

6. XEP-0049: Private XML Storage <http://xmpp.org/extensions/xep-0049.html>.

7. 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/>.

8. 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 1.1 (2007-11-07)

For security reasons, actively discouraged use of the password element; specified use of publish-subscribe private information nodes as the preferred storage mechanism; cleaned up the text and examples.

(psa)

Version 1.0 (2003-10-08)

Per a vote of the Jabber Council, changed status to Active; also added XML schema.

(psa)

Version 0.3 (2003-05-13)

Re-focused to document only the existing protocol in use.

(rcb)

Version 0.2 (2002-10-03)

Typos, etc...

(pgm)

Version 0.1 (2002-10-03)

Initial version.

(pgm)

END