You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
77 lines
2.9 KiB
Markdown
77 lines
2.9 KiB
Markdown
---
|
|
type: module
|
|
weight: 60
|
|
---
|
|
|
|
### Presence
|
|
|
|
Each user has the concept of presence information. This encodes:
|
|
|
|
- Whether the user is currently online
|
|
- How recently the user was last active (as seen by the server)
|
|
- Whether a given client considers the user to be currently idle
|
|
- Arbitrary information about the user's current status (e.g. "in a
|
|
meeting").
|
|
|
|
This information is collated from both per-device (`online`, `idle`,
|
|
`last_active`) and per-user (status) data, aggregated by the user's
|
|
homeserver and transmitted as an `m.presence` event. Presence events are
|
|
sent to interested parties where users share a room membership.
|
|
|
|
User's presence state is represented by the `presence` key, which is an
|
|
enum of one of the following:
|
|
|
|
- `online` : The default state when the user is connected to an event
|
|
stream.
|
|
- `unavailable` : The user is not reachable at this time e.g. they are
|
|
idle.
|
|
- `offline` : The user is not connected to an event stream or is
|
|
explicitly suppressing their profile information from being sent.
|
|
|
|
#### Events
|
|
|
|
{{presence\_events}}
|
|
|
|
#### Client behaviour
|
|
|
|
Clients can manually set/get their presence using the HTTP APIs listed
|
|
below.
|
|
|
|
{{presence\_cs\_http\_api}}
|
|
|
|
##### Last active ago
|
|
|
|
The server maintains a timestamp of the last time it saw a pro-active
|
|
event from the user. A pro-active event may be sending a message to a
|
|
room or changing presence state to `online`. This timestamp is presented
|
|
via a key called `last_active_ago` which gives the relative number of
|
|
milliseconds since the pro-active event.
|
|
|
|
To reduce the number of presence updates sent to clients the server may
|
|
include a `currently_active` boolean field when the presence state is
|
|
`online`. When true, the server will not send further updates to the
|
|
last active time until an update is sent to the client with either a)
|
|
`currently_active` set to false or b) a presence state other than
|
|
`online`. During this period clients must consider the user to be
|
|
currently active, irrespective of the last active time.
|
|
|
|
The last active time must be up to date whenever the server gives a
|
|
presence event to the client. The `currently_active` mechanism should
|
|
purely be used by servers to stop sending continuous presence updates,
|
|
as opposed to disabling last active tracking entirely. Thus clients can
|
|
fetch up to date last active times by explicitly requesting the presence
|
|
for a given user.
|
|
|
|
##### Idle timeout
|
|
|
|
The server will automatically set a user's presence to `unavailable` if
|
|
their last active time was over a threshold value (e.g. 5 minutes).
|
|
Clients can manually set a user's presence to `unavailable`. Any
|
|
activity that bumps the last active time on any of the user's clients
|
|
will cause the server to automatically set their presence to `online`.
|
|
|
|
#### Security considerations
|
|
|
|
Presence information is shared with all users who share a room with the
|
|
target user. In large public rooms this could be undesirable.
|