diff --git a/xep-0333.xml b/xep-0333.xml index f8feb312..f377c975 100644 --- a/xep-0333.xml +++ b/xep-0333.xml @@ -6,11 +6,11 @@
- Chat Markers - This specification describes a solution of marking the last received, displayed and acknowledged message in a chat. + Displayed Markers (was: Chat Markers) + This specification introduces a method to let the sender, or multiple participants in a group chat, know that a client has displayed messages up to a certain point. &LEGALNOTICE; 0333 - Deferred + Experimental 2017-03-01 2017-02-22 2017-02-11 @@ -30,6 +30,24 @@ im@spencermacdonald.com im@spencermacdonald.com + + Daniel + Gultsch + daniel@gultsch.de + daniel@gultsch.de + + + 0.5.0 + 2024-03-06 + dg + +
    +
  • Remove <received/> to not replicate &xep0184; functionality.
    • +
  • Remove <acknowledged/> because it was not implemented in the last 10 years and apparently is not needed.
    • +
  • Remove Disco feature. Opting in via <markable/> is enough
    • +
+ + 0.4.1 2023-07-19 @@ -100,170 +118,59 @@
-

The concept of delivery and read receipts has been popularised by other messaging services such as iMessage, Google Hangouts and Blackberry Messenger. - These services provide a visual indication of when a message has been delivered to any of the recipients resources and (optionally) when it has been read. - These visual indications (referred to herein as "Chat Markers") are synced between all of the sender's - and recipient's resources automatically, so the state of a chat is always consistent. - If one or more of the resources is not connected, it can fetch Chat Markers from the Message Archive upon reconnecting.

-

&xep0184; currently provides delivery receipts on a per message basis, - but it does not provide any mechanism for the user to indicate that they have read or acknowledged the message. - As delivery receipts are sent on a per message basis it would require multiple messages to "sync up" up delivery receipts between resources.

-

Moreover by using &xep0085; you could infer that a message has been read by the recipient, if they become active at any point after the message has been delivered, but again it would require multiple messages to "sync up" chat states between resources.

-

This XEP outlines an efficient message based protocol to provide this functionally using Chat Markers.

-

Note: Chat Markers do not mark each individual message, nor do they assume a reliable transport. This means that Chat Markers can only provide a heuristic solution, but this is often satisfactory for the majority of use cases.

- - - -

The term "active chat" refers to a chat that a user is currently active in. See &xep0085;.

-

The term "system notification" refers to a notification (typically a preview) that is displayed separately to a Chat.

-

The term "read" in the context of iMessage, Google Hangouts and Blackberry Messenger, directly maps to the displayed element in the Chat Marker namespace.

-

The term "markable message" refers to the stanza for which the original sender would like to receive a Chat Marker.

-

The term "Chat Marker" refers to the stanza by which the recipient replies to a "markable message" with a marker.

+

Letting the sender and/or multiple participants of a group chat know that an entity has displayed (Colloquially known as read) a message is a common feature in modern instant messaging.

+

&xep0184; currently provides delivery receipts on a per message basis, but it does not provide any mechanism for the user to indicate that they have read the message.

+

This specification defines a protocol for the sender of a message to let the recipient know they are interested in whether the recipient’s client has displayed the message and a protocol for the recipient to respond to said request. In group chats the explicit request is omitted and participants opportunistically share their displayed state with others.

+

Displayed Markers carry a semantic of all messages up to this point.

+

Note: Displayed Markers do not mark each individual message, nor do they assume a reliable transport. This means that Displayed Markers can only provide a heuristic solution, but this is often satisfactory for the majority of use cases.

 -

This document addresses the following requirements:

-
    -
  1. Enable a client to mark a message as markable.
    2. -
  2. Enable a client to mark the last received message in a chat.
    3. -
  3. Enable a client to mark the last displayed message in a chat.
    4. -
  4. Enable a client to mark the last acknowledged message in a chat.
    5. -
  5. Enable a client to fetch and set Chat Markers regardless of wether the other users in a chat are online.
    6. -
- - - -

If an entity supports the Chat Markers protocol, it MUST report that by including a &xep0030; - feature of "urn:xmpp:chat-markers:0" in response to disco#info requests:

- - - - -]]> - - - - - - ... - - ... - - -]]> - - -

Support can also be determined via &xep0115;, a.k.a. "caps".

- - - - -

If the sender knows only the recipient's bare JID, it cannot determine (via &xep0030; or &xep0115;) whether the intended recipient supports the Chat Markers protocol. In this case, the sender MAY send a Chat Marker or markable message.

- - -

If the sender knows a full JID for the recipient (e.g., via presence), it SHOULD attempt to determine (via service disco or entity capabilities) whether the client at that full JID supports the Chat Markers protocol before attempting to send a Chat Marker or markable message.

-

If the sender determines that the recipient's client does not support the Chat Markers protocol then it SHOULD NOT send Chat Markers or markable messages.

-

If the sender determines that the recipient's client supports the Chat Markers protocol then it MAY send a Chat Marker or markable message to that full JID.

- - -

To prevent looping, an entity MUST NOT send a Chat Marker to mark up to a Chat Marker.

- - - - -

Chat Markers use a dedicated protocol extension qualified by the 'urn:xmpp:chat-markers:0' namespace.

-

There are 4 allowable elements in the namespace, the first 'markable' indicates that a message can be marked with a Chat Marker and is therefore a "markable message".

-

The 3 other allowable elements in this namespace are used to mark a message (in order of significance):

+ -

The Chat Marker MUST have an 'id' which is the 'id' of the message being marked.

-

The Chat Marker message stanza MUST have a 'thread' child element if the message has been received, displayed or acknowledged in the context of a thread.

-

A Chat Marker Indicates that all messages up to and including that message 'id' have been marked. If a thread is supplied, a Chat Marker is only valid in the context of that thread.

- - - - sleeping - My lord, dispatch; read o'er these articles. + + +

An entity interested to know if the recipient has displayed a message attaches a <markable/> element qualified by the 'urn:xmpp:chat-markers:0' namespace to the message. The message MUST possess an 'id' attribute for traceability.

+ + Hi. How are you? + -]]> - - -

Note: A sender MUST include an 'id' attribute on every markable message.

- -

If recipient does not support the Chat Markers protocol it SHOULD NOT return an error.

- - - - sleeping - - -]]> - -

When the recipient sends a Chat Marker, it SHOULD ensure that the message stanza contains only the Chat Marker child element and optionally (when appropriate) a thread child element. Naturally, intermediate entities might add other extension elements to the message when routing or delivering the receipt message, e.g., a <delay/> element as specified in &xep0203;.

- - - -

Clients SHOULD use &xep0280; to support multiple online resources.

-

Clients SHOULD use &xep0136; or &xep0313; to support offline updating of Chat Markers. Chat Markers SHOULD be archived, so they can be fetched and set regardless of whether the other users in a chat are online.

-

Messages MUST have an 'id' to use Chat Markers.

-

Messages MUST include the 'markable' element to use Chat Markers.

-

Chat Markers MUST only move forward. If a Chat Marker is received for an earlier message than the current Chat Marker, it MUST be ignored by the client. -

-

Chat Markers for unknown messages MUST be ignored by the client. A client MAY store the Chat Marker incase the associated message is retrieved later. -

- - - - -

Less Significant Chat Markers SHOULD only be sent if they are later than the more significant Chat Marker i.e. if a Message has been marked as displayed, - a received Chat Marker should only be sent if it has a later timestamp than the displayed Chat Marker.

-

To avoid sending redundant Chat Markers while retrieving archived messages, Chat Markers SHOULD only be sent after retrieving the most recent message for a chat.

-

Only Messages that can be displayed in a chat SHOULD be markable.

- - -

Clients MUST NOT mark a message as acknowledged without any user interaction.

- - -

Clients MAY mark a sent or received message, as Chat Markers are inclusive of of both previously sent and received messages.

- - -

Chat Markers MAY be used alongside Delivery Receipts.

+]]> - -

Chat Markers MAY be used alongside Chat States.

+ +

To let the sender know a message has been displayed an entity sends a message with a <displayed/> element qualified by the 'urn:xmpp:chat-markers:0' namespace. The <displayed/> element MUST have an 'id' attribute that copies the value from the 'id' attribute of the message it refers to.

+

A Displayed Marker MAY be sent to the bare JID of the entity that requested it.

+

If multiple messages are displayed at once an entity SHOULD only send a <displayed/> marker for the most recent, received message.

+

To prevent looping, an entity MUST NOT send a Displayed Marker as a response to a Displayed Marker.

+ + + +]]> - -

Markers may be used within a MUC to indicate read status of each occupant.

+ +

Displayed Markers can be used within group chats to indicate read status of each occupant.

Within the context of a MUC messages are relayed through the MUC's own JID. In a MUC that preserves the 'id' attribute chosen by the sender of the message this 'id' attribute cannot be considered unique, as it may be unintentionally or even maliciously reused by another MUC occupant.

-

Therefore, if a MUC announces support for &xep0359; then clients MUST always use - the MUC-assigned id for Chat Markers. The id will be contained in a <stanza-id/> + the MUC-assigned id for Displayed Markers. The id will be contained in a <stanza-id/> element inserted into the stanza with a 'by' attribute matching the MUC's own JID.

-

As per XEP-0359 security considerations, if XEP-0359 support is not announced on the MUC room's JID then <stanza-id/> elements with a 'by' attribute that match the MUC's JID should be considered spoofed and MUST be ignored.

+

In group chats the Displayed Marker MAY be sent opportunistically, meaning without an explicit <markable/> request from the sender. While the sender might not be interested in or have support for Display Markers, other participants of the group chat could be interested in them.

- + ]]> - + +
    +
  • Displayed Marker only move forward. Receiving a Display Marker with an id-attribute that references a message older than the current local representation is considered redundant and MUST be ignored.
    • +
  • Displayed Marker with an id-attribute that references a message not found in the respective chat MUST be ignored.
    • +
  • Entities MUST not sent Displayed Markers for outgoing messages that were sent by the same or a different resource of the same entity (received for example via &xep0280; or &xep0313;).
    • +
+ + + +

Graphical representations of displayed markers for example in the form of checkmarks need to be made available for visually impaired users.

+ + -

A user may not wish to disclose that they have received, displayed or acknowledge a message.

-

It is possible for a sender to leak its presence when updating Chat Markers; - therefore, a sender SHOULD NOT send Chat Markers to recipients who are not otherwise authorized to view its presence.

+
    +
  • A user may not wish to disclose that they have displayed or acknowledge a message.
    • +
  • It is possible for a sender to leak its presence when updating Displayed Markers; therefore, a sender SHOULD NOT send Displayed Markers to recipients who are not otherwise authorized to view its presence.
    • +
  • To accurately and reliably match Displayed Markers to current participants of a group chat, implementations MUST use the real JID (when available, for example in non-anonymous MUCs) or &xep0421;.
    • +
+ + + +

Letting others know that one has displayed (read) a message is not a desirable feature for everyone. Clients SHOULD provide ways to opt-out of this feature.

 +

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

 +

This specification defines the following XML namespace:

@@ -311,6 +237,11 @@ + + +

Earlier drafts of this specification included <received/> and <acknowledged/> with the same up to this point semantic as the remaining <displayed/>. However in the review phase it was concluded that most implementers prefer the per-message precision of &xep0184; for received tracking. While <displayed/> has been widely implemented during a 10+ year review phase there was seemingly no demand for <acknowledged/>.

+ + - - - - - - - - - - @@ -357,17 +278,6 @@ - - - - - - - - - - - ]]>