XEP-0097: iCal Envelope

Abstract:A simple mechanism to transport iCal data over the jabber protocol
Author:Justin Kirby
Copyright:© 1999 – 2018 XMPP Standards Foundation. SEE LEGAL NOTICES.
Type:Standards Track
Last Updated:2003-06-10

WARNING: This document has been automatically Deferred after 12 months of inactivity in its previous Experimental state. Implementation of the protocol described herein is not recommended for production systems. However, exploratory implementations are encouraged to resume the standards process.

Table of Contents

1. Introduction
2. Disco
3. Sending iCal Data
4. Receiving iCal Data
5. IANA Considerations
6. XMPP Registrar Considerations
7. Formal Definition
    7.1. Schema
    7.2. DTD
8. Unresolved Issues

    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

This will be the first, in a series (hopefully), of specifications which will define how to utilize GroupWare over jabber. While GroupWare is extremely broad subject, this document will focus on iCal [1]. Since iCal is a defined standard which is transport-agnostic, all this document will do is define how iCal will be transported over Jabber.

What this document will cover:

2. Disco

Before sending iCal messages to a jabber entity, a disco query should be performed in order to discover whether or not that entity supports iCal Envelopes.

Example 1.

  <query xmlns='http://jabber.org/protocol/disco#info'/>

If the jabber entity supports iCal Envelopes, then it MUST respond with http://jabber.org/protocol/gw/ical as a feature.

Example 2.

  <query xmlns='http://jabber.org/protocol/disco#info'>
    <feature var='http://jabber.org/protocol/gw/ical'/>

3. Sending iCal Data

To send iCal, all that needs to be done is wrap the iCal data in a ical element. All iCal data sent MUST be in the ical element in the http://jabber.org/protocol/gw/ical namespace. The CDATA section is optional and is used here simply to make it readable.

Other than wrapping iCal in XML, the data itself MUST follow the ietf 2445 RFC [2]

Example 3.

<message to="jdev@jabber.org" from="calendar.jabber.org" type="normal">
    Protocol gathering every Tuesday at 22:00 UTC
    located in foundation@conference.jabber.org
  <ical xmlns="http://jabber.org/protocol/gw/ical">
      PRODID:-//Ximian//NONSGML Evolution Calendar//EN
      DESCRIPTION:discuss jeps

As a convenience for users which do not have ical support the sender may want to place human readable information in the <body/> for the receiver to read.

4. Receiving iCal Data

When a client receives a message containing iCal data there are a few options which are considered reasonable.

Per the jabber standard, any message received which the entity does not understand CAN be ignored. This behavior is expected of clients which have not implemenred this jep.

The entity may display the ical data as text to the user, this is not recommended for obvious reasons. However, some data is better than no data, so this is considered preferable to just dropping the message stanza.

Most users today have some form of calendaring functionality available to them which supports the iCal standard. Simply redirecting the received ical to the user's preferred calendaring application would be the ideal scenario.

5. IANA Considerations

This document requires no interaction with the Internet Assigned Numbers Authority (IANA)

6. XMPP Registrar Considerations

The 'http://jabber.org/protocol/gw/ical' namespace is registered with the XMPP Registrar as a result of this document.

7. Formal Definition

7.1 Schema


7.2 DTD


8. Unresolved Issues

The following are issues that need to be resolved


Appendix A: Document Information

Series: XEP
Number: 0097
Publisher: XMPP Standards Foundation
Status: Deferred
Type: Standards Track
Version: 0.1
Last Updated: 2003-06-10
Approving Body: XMPP Council
Dependencies: XEP-0030
Supersedes: None
Superseded By: None
Short Name: ice
Source Control: HTML
This document in other formats: XML  PDF

Appendix B: Author Information

Justin Kirby

Email: justin@openaether.org
JabberID: zion@openaether.org

Appendix C: Legal Notices


This XMPP Extension Protocol is copyright © 1999 – 2018 by the XMPP Standards Foundation (XSF).


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 <https://xmpp.org/about/xsf/ipr-policy> or obtained by writing to XMPP Standards Foundation, P.O. Box 787, Parker, CO 80134 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. iCalendar http://www.ietf.org/html.charters/calsch-charter.html

2. 2445 RFC http://www.ietf.org/rfc/rfc2445.txt

Appendix H: Revision History

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

Version 0.1 (2003-06-10)

Initial draft (jk). (jk)