This JEP defines a standards-track protocol for communicating notifications related to chat states, including message composing events.
NOTICE: This JEP is currently within Last Call or under consideration by the Jabber Council for advancement to the next stage in the JSF standards process. For further details, visit <http://www.jabber.org/council/queue.shtml>.
Status: Proposed
Type: Standards Track
Number: 0085
Version: 0.14
Last Updated: 2005-07-20
JIG: Standards JIG
Approving Body: Jabber Council
Dependencies: XMPP Core, XMPP IM
Supersedes: None
Superseded By: None
Short Name: chatstates
Email: stpeter@jabber.org
JID: stpeter@jabber.org
Email: dizzyd@jabber.org
JID: dizzyd@jabber.org
This Jabber Enhancement Proposal is copyright 1999 - 2005 by the Jabber Software Foundation (JSF) and is in full conformance with the JSF's Intellectual Property Rights Policy <http://www.jabber.org/jsf/ipr-policy.shtml>. This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v1.0 or later (the latest version is presently available at <http://www.opencontent.org/openpub/>).
The preferred venue for discussion of this document is the Standards-JIG discussion list: <http://mail.jabber.org/mailman/listinfo/standards-jig>.
The Extensible Messaging and Presence Protocol (XMPP) is defined in the XMPP Core (RFC 3920) and XMPP IM (RFC 3921) specifications contributed by the Jabber Software 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 JEP 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.
The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.
Many instant messaging systems include notifications about the state of one's conversation partner in a one-to-one chat (or, sometimes, in a many-to-many chat). Usually these are limited to notification that one's partner is currently typing -- e.g., the Composing event in JEP-0022 (see Message Events [1]). However, a composing event is essentially information about a person's participation in or involvement with the chat "session" and therefore is really a session-level state rather than a per-message event -- e.g., the Delivered and Displayed events in JEP-0022. While the composing event is interesting, the concept of a session-level state can be extended to answer a variety of questions about the participation of a person in a real-time chat conversation, such as:
To answer such questions, this JEP supplements the traditional composing state by defining four additional chat states (paused, active, inactive, gone), for a total of five states that (it is hoped) together fully describe the possible states of a person's participation in or involvement with a chat conversation. [2]
In essence, chat state notifications can be thought of as a form of chat-specific presence. For example, consider what might happen if a user "loses" a chat window on his desktop; the user might still be interacting with his messaging client (thus never automatically changing his basic presence to "away"), but the user's state with regard to the chat session might change progressively from active to inactive to gone. This information would help the user's conversation partner understand why she has not received a response to her messages in the chat session.
Chat state notifications can appear in two kinds of <message/> stanzas:
The five chat states specified in this document are described below. The suggested triggers and state changes are simply that: suggestions. It is up to the implementation to determine when to generate chat state notifications and which notifications to generate.
Table 1: Chat States
| State | Definition | Suggested Triggers | Suggested State Changes |
|---|---|---|---|
| <active/> | User is actively participating in the chat session. | User accepts an initial content message, sends a content message, gives focus to the chat interface, or is otherwise paying attention to the conversation. | <inactive/>, <composing/> |
| <composing/> | User is composing a message. | User interacts with a message input interface specific to this chat session (e.g., types in the input area of a chat window). | <active/>, <paused/> |
| <paused/> | User had been composing but now has stopped. | User was composing but stops interacting with the input interface for a short period of time (e.g., 5 seconds) or starts interacting with another chat interface or application. | <active/>, <composing/>, <inactive/> |
| <inactive/> | User is not actively participating in the chat session. | User does not interact with the chat interface for an intermediate period of time (e.g., 30 seconds), minimizes the chat interface, or starts interacting with another chat interface or application. | <active/>, <gone/> |
| <gone/> | User has ended their participation in the chat session. | User terminates the chat interface (e.g., closes a chat window) or does not interact with the chat interface, system, or device for a long period of time (e.g., 2 minutes). | <active/> |
The following figure attempts to capture the possible state transitions in visual form.
o (start)
|
|
INACTIVE <--> ACTIVE <--> COMPOSING
| ^ |
| | |
+ <------ PAUSED <-----> +
Note: All four of the states shown may transition to the GONE state.
In the absence of explicit negotiation of a one-to-one chat session between a User and Contact (e.g., as specified in Chat Session Negotiation [4]) or explicit discovery by the User of the Contact's capabilities (e.g., as gained through Service Discovery [5] or Entity Capabilities [6]), the following business rules apply to the use of chat state notifications in the context of one-to-one chat sessions:
The foregoing rules imply that the sending of chat state notifications is bidirectional (i.e., both User and Contact will either send or not send chat state notifications) rather than unidirectional (i.e., one of the conversation partners will send chat state notifications but the other will not); this is intentional.
Table 2: Requirements for Supporting Each Chat State
| Chat State | Requirement |
|---|---|
| <active/> | MUST |
| <composing/> | MUST |
| <paused/> | SHOULD |
| <inactive/> | SHOULD |
| <gone/> | SHOULD |
A client MUST allow the user to configure whether he or she wants to send chat state notifications.
Note: Support for only <active/> and <composing/> is functionally equivalent to supporting the Composing event from JEP-0022.
Even if the user types continuously for a long time (e.g., while composing a lengthy reply), the client MUST NOT send more than one standalone <composing/> notification in a row. More generally, a client MUST NOT send a second instance of any given standalone notification (i.e., a standalone notification MUST be followed by a different state, not repetition of the same state). However, every content message SHOULD contain an <active/> notification.
Chat state notifications MAY be sent in the context of groupchat rooms (e.g., as defined in Multi-User Chat [7]). The following business rules apply:
Note: Use of chat state notifications in the context of groupchat may result in multicasting of such notifications. Forewarned is forearmed.
While chat state notifications provide a mechanism for managing chat threads (i.e., the <thread/> element), support for threads is OPTIONAL. However, if all of the clients participating in a chat both support and use threads, the following additional business rules apply:
Servers in constrained network environments (e.g., serving small-footprint clients via Jabber HTTP Polling [9] or HTTP Binding [10]) and services that rebroadcast message stanzas (e.g., Multi-User Chat services) MAY process standalone notifications differently from other messages. In particular, a server or service MAY refuse to deliver standalone notifications to its users, and SHOULD NOT store them offline. In contrast to JEP-0022, chat state notifications are completely the responsibility of the client, and MUST NOT be generated by a server or service.
In the following conversation, both User and Contact support chat state notifications.
Example 1. User Sends Initial Content Message With <active/> Notification
<message
from='bernardo@shakespeare.lit/pda'
to='francisco@shakespeare.lit'
type='chat'>
<body>Who's there?</body>
<active xmlns='http://jabber.org/protocol/chatstates'/>
</message>
Example 2. Contact's Client Sends Content Message Reply With <active/> Notification
<message
from='francisco@shakespeare.lit/elsinore'
to='bernardo@shakespeare.lit/pda'
type='chat'>
<body>Nay, answer me: stand, and unfold yourself.</body>
<active xmlns='http://jabber.org/protocol/chatstates'/>
</message>
Because the User now knows that the Contact supports chat state notifications, the User can send other notification types.
Example 3. User Sends Standalone <composing/> Notification
<message
from='bernardo@shakespeare.lit/pda'
to='francisco@shakespeare.lit/elsinore'
type='chat'>
<composing xmlns='http://jabber.org/protocol/chatstates'/>
</message>
Example 4. User Sends a Content Message Reply With <active/> Notification
<message
from='bernardo@shakespeare.lit/pda'
to='francisco@shakespeare.lit/elsinore'
type='chat'>
<body>Long live the king!</body>
<active xmlns='http://jabber.org/protocol/chatstates'/>
</message>
And so forth.
The following conversation flow illustrates in more detail the workings of chat state notifications (in this case also using threads).
Example 5. User Sends Initial Content Message
<message
from='romeo@shakespeare.lit/orchard'
to='juliet@capulet.com'
type='chat'>
<thread>act2scene2chat1</thread>
<body>
I take thee at thy word:
Call me but love, and I'll be new baptized;
Henceforth I never will be Romeo.
</body>
<active xmlns='http://jabber.org/protocol/chatstates'/>
</message>
At this point Juliet's client knows that Romeo's client supports chat state notifications. Thus she replies to the initial content message and her client includes a notification that her state is <active/>:
Example 6. Contact's Client Sends Content Message Reply With <active/> Notification
<message
from='juliet@capulet.com/balcony'
to='romeo@shakespeare.lit/orchard'
type='chat'>
<thread>act2scene2chat1</thread>
<body>
What man art thou that thus bescreen'd in night
So stumblest on my counsel?
</body>
<active xmlns='http://jabber.org/protocol/chatstates'/>
</message>
And so the conversation continues. After a while, Juliet asks a question that brings Romeo up short. Romeo begins composing a reply to Juliet's heartfelt question, and his Jabber client notifies Juliet that he is composing a reply.
Example 7. User's Client Sends Standalone <composing/> Notification
<message
from='romeo@montague.net/orchard'
to='juliet@capulet.com/balcony'
type='chat'>
<thread>act2scene2chat1</thread>
<composing xmlns='http://jabber.org/protocol/chatstates'/>
</message>
Romeo realizes his reply is too rash and pauses to choose the right words; after some (configurable) time period, his Jabber client senses the delay and sends a state of <paused/>.
Example 8. User's Client Sends Standalone <paused/> Notification
<message
from='romeo@montague.net/orchard'
to='juliet@capulet.com/balcony'
type='chat'>
<thread>act2scene2chat1</thread>
<paused xmlns='http://jabber.org/protocol/chatstates'/>
</message>
Romeo starts composing again, and his Jabber client sends a <composing/> notification to Juliet's client.
Example 9. User's Clients Sends Standalone <composing/> Notification
<message
from='romeo@montague.net/orchard'
to='juliet@capulet.com/balcony'
type='chat'>
<thread>act2scene2chat1</thread>
<composing xmlns='http://jabber.org/protocol/chatstates'/>
</message>
Romeo finally sends his reply.
Example 10. User Replies
<message
from='romeo@montague.net/orchard'
to='juliet@capulet.com/balcony'
type='chat'>
<thread>act2scene2chat1</thread>
<body>Neither, fair saint, if either thee dislike.</body>
<active xmlns='http://jabber.org/protocol/chatstates'/>
</message>
The conversation ebbs and flows, waxes and wanes, until Juliet is called away by her Nurse...
Example 11. Contact's Client Sends Content Message
<message
from='juliet@capulet.com/balcony'
to='romeo@shakespeare.lit/orchard'
type='chat'>
<thread>act2scene2chat1</thread>
<body>
I hear some noise within; dear love, adieu!
Anon, good nurse! Sweet Montague, be true.
Stay but a little, I will come again.
</body>
<active xmlns='http://jabber.org/protocol/chatstates'/>
</message>
We suppose that Juliet minimizes the chat window, so her client generates an <inactive/> notification:
Example 12. Contact's Client Sends Standalone <inactive/> Notification
<message
from='juliet@capulet.com/balcony'
to='romeo@shakespeare.lit/orchard'
type='chat'>
<thread>act2scene2chat1</thread>
<inactive xmlns='http://jabber.org/protocol/chatstates'/>
</message>
When she returns and brings the window up again, her client generates an <active/> notification:
Example 13. Contact's Client Sends Standalone <active/> Notification
<message
from='juliet@capulet.com/balcony'
to='romeo@shakespeare.lit/orchard'
type='chat'>
<thread>act2scene2chat1</thread>
<active xmlns='http://jabber.org/protocol/chatstates'/>
</message>
The conversation continues, but Juliet is called away again by that nagging Nurse:
Example 14. Contact's Client Sends Content Message
<message
from='juliet@capulet.com/balcony'
to='romeo@shakespeare.lit/orchard'
type='chat'>
<thread>act2scene2chat1</thread>
<body>
A thousand times good night!
</body>
<active xmlns='http://jabber.org/protocol/chatstates'/>
</message>
We suppose that Juliet closes the chat window, so her client generates a <gone/> notification:
Example 15. Contact's Client Sends Standalone <gone/> Notification
<message
from='juliet@capulet.com/balcony'
to='romeo@shakespeare.lit/orchard'
type='chat'>
<thread>act2scene2chat1</thread>
<gone xmlns='http://jabber.org/protocol/chatstates'/>
</message>
Romeo's client now considers the chat thread to be over and generates a new Thread ID when he sends a new message:
Example 16. User's Client Sends Content Message with New Thread ID
<message
from='romeo@shakespeare.lit/orchard'
to='juliet@capulet.com/balcony'
type='chat'>
<thread>act2scene2chat2</thread>
<body>
A thousand times the worse, to want thy light.
Love goes toward love, as schoolboys from their books,
But love from love, toward school with heavy looks.
</body>
<active xmlns='http://jabber.org/protocol/chatstates'/>
</message>
When Juliet returns to her computer on the balcony, she finds the new message from Romeo. When she finishes her reply, her client includes both an <active/> notification and the new Thread ID with the body of her reply:
Example 17. Contact's Client Sends Content Message
<message
from='juliet@capulet.com/balcony'
to='romeo@shakespeare.lit/orchard'
type='chat'>
<thread>act2scene2chat2</thread>
<body>
Hist! Romeo, hist! O, for a falconer's voice,....
</body>
<active xmlns='http://jabber.org/protocol/chatstates'/>
</message>
And so forth.
My, these star-crossed lovers do go on, don't they?
A client that receives a chat state notification should expect that it may never receive another message or chat state notification from the other entity (e.g., because the other entity crashes or goes offline) and should plan accordingly.
The states of a chat thread may reveal information about a user's interaction with his or her computer, including his or her physical presence; such information SHOULD NOT be revealed to conversation partners who are not trusted to know such information. Client implementations MUST provide a mechanism that enables the user to disable chat state notifications if desired.
This JEP requires no interaction with the Internet Assigned Numbers Authority (IANA) [11].
The Jabber Registrar [12] shall include 'http://jabber.org/protocol/chatstates' in its registry of protocol namespaces.
<?xml version='1.0' encoding='UTF-8'?>
<xs:schema
xmlns:xs='http://www.w3.org/2001/XMLSchema'
targetNamespace='http://jabber.org/protocol/chatstates'
xmlns='http://jabber.org/protocol/chatstates'
elementFormDefault='qualified'>
<xs:element name='active' type='empty'/>
<xs:element name='composing' type='empty'/>
<xs:element name='gone' type='empty'/>
<xs:element name='inactive' type='empty'/>
<xs:element name='paused' type='empty'/>
<xs:simpleType name='empty'>
<xs:restriction base='xs:string'>
<xs:enumeration value=''/>
</xs:restriction>
</xs:simpleType>
</xs:schema>
1. JEP-0022: Message Events <http://www.jabber.org/jeps/jep-0022.html>.
2. These states do not necessarily refer to the state of the client interface and certainly not to the disposition of a particular message. However, the user's involvement with the system, device, chat interface, or input interface can provide important clues regarding the user's involvement with the chat session, which should be used by the client in determining when to generate chat state notifications.
3. RFC 3921: Extensible Messaging and Presence Protocol (XMPP): Instant Messaging and Presence <http://www.ietf.org/rfc/rfc3921.txt>.
4. JEP-0155: Chat Session Negotiation <http://www.jabber.org/jeps/jep-0155.html>.
5. JEP-0030: Service Discovery <http://www.jabber.org/jeps/jep-0030.html>.
6. JEP-0115: Entity Capabilities <http://www.jabber.org/jeps/jep-0115.html>.
7. JEP-0045: Multi-User Chat <http://www.jabber.org/jeps/jep-0045.html>.
8. RFC 3921: Extensible Messaging and Presence Protocol (XMPP): Instant Messaging and Presence <http://www.ietf.org/rfc/rfc3921.txt>.
9. JEP-0025: Jabber HTTP Polling <http://www.jabber.org/jeps/jep-0025.html>.
10. JEP-0124: HTTP Binding <http://www.jabber.org/jeps/jep-0124.html>.
11. 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/>.
12. The Jabber Registrar maintains a list of reserved Jabber protocol namespaces as well as registries of parameters used in the context of protocols approved by the Jabber Software Foundation. For further information, see <http://www.jabber.org/registrar/>.
END