XEP-0435: Reminders

Abstract
This specification provides a way to set up reminders.
Author
Marcos De Vera Piquero
Copyright
© 1999 – 2020 XMPP Standards Foundation. SEE LEGAL NOTICES.
Status

Experimental

WARNING: This Standards-Track document is Experimental. Publication as an XMPP Extension Protocol does not imply approval of this proposal by the XMPP Standards Foundation. Implementation of the protocol described herein is encouraged in exploratory implementations, but production systems are advised to carefully consider whether it is appropriate to deploy implementations of this protocol before it advances to a status of Draft.
Type
Standards Track
Version
0.1.0 (2020-03-31)
Document Lifecycle
  1. Experimental
  2. Proposed
  3. Draft
  4. Final

1. Introduction

It is sometimes useful, while reading some conversations, to be reminded about it at some point in the future. This specification proposes a mechanism to allow clients to set up such reminders.

2. Glossary

Reminder
An automatically generated message addressed to an entity sent at a given time. Its goal is to remind the creating entity about something.

3. Requirements

This protocol requires handling of dates and times, as such it conforms to XMPP Date and Time Profiles (XEP-0082) [1].

4. Discovering support

An entity may wish to discover if a service supports the Reminders feature; in order to do so, it sends a service discovery information query to the server..

Example 1. Client requests information about a server
<iq from='juliet@capulet.net/balcony'
    id='disco1'
    to='capulet.net'
    type='get'>
  <query xmlns='http://jabber.org/protocol/disco#info'/>
</iq>

If the server supports the Reminders feature, it MUST specify the 'urn:xmpp:reminders:0' feature in its service discovery information features as specified in Service Discovery (XEP-0030) [2]

Example 2. Server advertises support for reminders
<iq to='juliet@capulet.net/balcony' id='disco1' from='capulet.net'
	type='result'>
  <query xmlns='http://jabber.org/protocol/disco#info'>
    …  
    <feature var='urn:xmpp:reminders:0'/>
    …
  </query>
</iq>

5. Use Cases

For end users, this provides a way to be reminded about stuff while being in a conversation, without the need to leave it and go to some calendar application or similar and create a full event there. By setting a reminder, a user will be notified by the server at whatever given time the reminder is created with and with whatever the description was set for such a reminder.

5.1 Creating a reminder

A user wants to create a new reminder. For creating a reminder, an entity MUST send an IQ stanza with the 'type' attribute with a value of "set" and a direct <reminder/> child qualified by the "urn:xmpp:reminders:0" namespace.

Example 3. User creates a new reminder
<iq from='juliet@capulet.net/balcony'
    to='capulet.net'
    id='abc123'
    type='set'>
  <reminder xmlns='urn:xmpp:reminders:0'>
    <date>2020-02-19T23:41:00Z</date>
    <text xml:lang='en'>Please go sleep before it's too late</text>
  </reminder>
</iq> 
Example 4. Server acknowledges the reminder creation
<iq id='abc123'
    to='juliet@capulet.net/balcony'
    from='capulet.net'
    type='result'>
  <reminder xmlns='urn:xmpp:reminders:0' id='d414cec2-5369-11ea-9455-8b8d265047d9'>
    <date>2020-02-19T23:41:00Z</date>
    <text xml:lang='en'>Please go sleep before it's too late</text>
  </reminder>
</iq>

Whenever the reminder's data sent by a client is not complete or in an invalid format, the server MUST send an error stanza of type 'modify' and a 'bad-request' condition.

Example 5. Server sends a bad-request error response
<iq id='bad1'
    to='capulet.net'
    from='juliet@capulet.net/balcony'
    type='set'>
  <reminder xmlns='urn:xmpp:reminders:0'>
    <date>Tomorrow at noon</date>
	<text xml:lang='en'>Lunch at Romeo's</text>
  </reminder>
</iq>

<iq id='bad1'
    to='juliet@capulet.net/balcony'
    from='capulet.net'
    type='error'>
  <error type='modify'>
    <bad-request xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
  </error>
</iq>

In the event of a client trying to set a reminder in the past, the server MUST send an error stanza of type 'modify' and a 'gone' condition.

Example 6. Server sends a gone error response
<iq id='bad2'
    to='capulet.net'
    from='juliet@capulet.net/balcony'
    type='set'>
  <reminder xmlns='urn:xmpp:reminders:0'>
    <date>2000-01-01T00:00:00Z</date>
    <text xml:lang='en'>New Year's party</text>
  </reminder>
</iq>

<iq id='bad2'
    to='juliet@capulet.net/balcony'
    from='capulet.net'
    type='error'>
  <error type='modify'>
    <gone xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
  </error>
</iq>

5.2 Server sends a reminder

Whenever the time for a reminder arrives, the server MUST send a message with the reminder to the creating entity.

Example 7. Server sends a reminder
<message from='capulet.net' to='juliet@capulet.net/balcony' id='reminder1'>
  <reminder xmlns='urn:xmpp:reminders:0' id='d414cec2-5369-11ea-9455-8b8d265047d9'>
    <date timezone='UTC'>2020-02-19T23:41:00Z</date>
    <text xml:lang='en'>Please go sleep before it's too late</text>
  </reminder>
</message>

After sending a reminder, the server MAY choose to delete it from its storage.

5.3 Client cancels a reminder

There may be the case where a user wants to cancel an already set reminder. To do so, the client MUST send an IQ stanza of type 'set' with a 'reminder' child containing the 'id' attribute of the reminder to be deleted, without any additional child.

Example 8. Client deletes a reminder
<iq id='abc2'
    from='juliet@capulet.net/balcony'
    to='capulet.net'
    type='set'>
  <reminder xmlns='urn:xmpp:reminders:0' id='d414cec2-5369-11ea-9455-8b8d265047d9'/>
</iq>
Example 9. Server acknowledges a reminder deletion
<iq id='abc2'
    to='juliet@capulet.net/balcony'
    from='capulet.net'
    type='result'>
  <reminder xmlns='urn:xmpp:reminders:0' id='d414cec2-5369-11ea-9455-8b8d265047d9'/>
</iq>

6. Internationalization Considerations

As stated in the requirements, the 'date' element MUST contain a valid XMPP Date and Time Profiles (XEP-0082) [1] DateTime value.

7. Security Considerations

This document introduces no additional security considerations above and beyond those defined in the documents on which it depends.

8. IANA Considerations

No interaction with the Internet Assigned Numbers Authority (IANA) [3] is required as a result of this document.

9. XMPP Registrar Considerations

This specification defines the following XML namespace:

Upon advancement of this specification from a status of Experimental to a status of Draft, the XMPP Registrar [4] shall add the foregoing namespace to the registry located at <https://xmpp.org/registrar/namespaces.html>, as described in Section 4 of XMPP Registrar Function (XEP-0053) [5].

10. XML Schema

TODO


Appendices

Appendix A: Document Information

Series
XEP
Number
0435
Publisher
XMPP Standards Foundation
Status
Experimental
Type
Standards Track
Version
0.1.0
Last Updated
2020-03-31
Approving Body
XMPP Council
Dependencies
XMPP Core, XEP-0082
Supersedes
None
Superseded By
None
Short Name
NOT_YET_ASSIGNED
Source Control
HTML

This document in other formats: XML  PDF

Appendix B: Author Information

Marcos De Vera Piquero
Email
marcos@tenak.net
JabberID
marcos@tenak.net

Copyright

This XMPP Extension Protocol is copyright © 1999 – 2020 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 <https://xmpp.org/about/xsf/ipr-policy> or obtained by writing to XMPP Standards Foundation, P.O. Box 787, Parker, CO 80134 USA).

Visual Presentation

The HTML representation (you are looking at) is maintained by the XSF. It is based on the YAML CSS Framework, which is licensed under the terms of the CC-BY-SA 2.0 license.

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-0082: XMPP Date and Time Profiles <https://xmpp.org/extensions/xep-0082.html>.

2. XEP-0030: Service Discovery <https://xmpp.org/extensions/xep-0030.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 <https://xmpp.org/registrar/>.

5. XEP-0053: XMPP Registrar Function <https://xmpp.org/extensions/xep-0053.html>.

Appendix H: Revision History

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

  1. Version 0.1.0 (2020-03-31)
    Accepted by vote of Council on 2020-03-04.
    XEP Editor (jsc)
  2. Version 0.0.1 (2020-02-17)

    Initial version

    mdvp

END