Question: How can I get information about a room's members?

[yveoch]

Hi,

I'm trying to build an IOU bot for matrix (https://github.com/dryvenn/matrix-iou-bot) and I was wondering:

• How do I get a user's "display name" from his ID?

• How do I get the list of all the users in a room?

The goal here is to map human-friendly names in a message to actual users.

Any help appreciated!

[kegsay]

There is no support currently to do this in gomatrix. However, there is an HTTP API you can use which will return the information you want. This is the /joined_members API which is supported on Synapse v0.18.5-rc3 or above. This is a new API which has not yet landed on the specification. Usage:

GET /_matrix/client/r0/rooms/%21ErgjgSgsdWEfw%3Amatrix.org/joined_members HTTP/1.1
Content-Type: application/json

{
  "joined": {
    "@alice:matrix.org": {
        "display_name": "Alice",
        "avatar_url": null
    },
    "@bob:matrix.org": {
        "display_name": "Bob",
        "avatar_url": null
    }
  }
}

Or see https://github.com/matrix-org/matrix-appservice-bridge/blob/master/lib/components/app-service-bot.js#L55 for a JS implementation.

[kegsay]

I have added /joined_members to the endpoint checklist bug (#9) - closing this issue.

[kegsay]

Be aware that this API is separate to /sync, so it is racey. If you really care about getting the correct display name for each message for circumstances like:

Alice: test
<Alice changed name to Bob>
Bob: test

then you will need to listen for the membership change events on the DefaultSyncer.

[yveoch]

Ok thanks!!