3.3 KiB
Rich replies
Rich replies are a
special kind of relationship which
effectively quotes the referenced event for the client to render/process how
it wishes. They are normally used with m.room.message events.
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{{% changed-in v="1.3" %}}
Until v1.3 of the spec, rich replies were limited to m.room.message events
which could represent an HTML-formatted body. As of v1.3 this is now expanded
to all event types by dropping the requirement that an HTML-formatted body
be included.
Additionally, a rich reply can reference any other event type as of v1.3.
Previously, a rich reply could only reference another m.room.message event.
{{% /boxes/note %}}
{{% boxes/note %}}
{{% changed-in v="1.13" %}}
In previous versions of the specification, rich replies could include a fallback
representation of the original message message in the body (using a prefix
sequence) and formatted_body (using a custom HTML element) for clients that do
not support rich replies. This is no longer the case, but clients SHOULD still
remove this fallback before rendering the event.
To strip the fallback on the body, the client should iterate over each
line of the string, removing any lines that start with the fallback
prefix sequence (> , including the trailing space) and stopping when
a line is encountered without the prefix.
To strip the fallback on the formatted_body of an m.room.message event with
a format of org.matrix.custom.html: if theformatted_body begins with an
<mx-reply> start tag, the client should remove the entirety of the
<mx-reply> element.
{{% /boxes/note %}}
Though rich replies form a relationship to another event, they do not
use rel_type to create this relationship. Instead, a subkey named m.in_reply_to
is used to describe the reply's relationship, leaving the other properties of
m.relates_to to describe the primary relationship of the event. This means
that if an event is simply in reply to another event, without further relationship,
the rel_type and event_id properties of m.relates_to become optional.
An example reply would be:
{
"content": {
"m.relates_to": {
"m.in_reply_to": {
"event_id": "$another_event"
}
},
"body": "That sounds like a great idea!"
},
// other fields as required by events
}
Note that the event_id of the m.in_reply_to object has the same requirements
as if it were to be under m.relates_to directly instead.
Mentioning the replied to user
In order to notify users of the reply, it may be desirable to include the sender
of the replied to event and any users mentioned in that event. See
user and room mentions for additional information.
An example including mentioning the original sender and other users:
{
"content": {
"m.relates_to": {
"m.in_reply_to": {
"event_id": "$another_event"
}
},
"body": "That sounds like a great idea!",
"m.mentions": {
"user_ids": [
// The sender of $another_event.
"@alice:example.org",
// Another Matrix ID copied from the m.mentions property of $another_event.
"@bob:example.org"
]
}
},
// other fields as required by events
}