Janus-gateway "join" http call return "ack" only

Question

I am new to Janus with javascript, I have a room like this:

{
    "janus": "success",
    "session_id": 266646464364358,
    "transaction": "MUcPg6Wu5jhr",
    "sender": 4377145860586972,
    "plugindata": {
        "plugin": "janus.plugin.videoroom",
        "data": {
            "videoroom": "success",
            "list": [
                {
                    "room": 11,
                    "description": "Room 11",
                    "pin_required": false,
                    "is_private": false,
                    "max_publishers": 3,
                    "bitrate": 0,
                    "fir_freq": 0,
                    "require_pvtid": false,
                    "require_e2ee": false,
                    "dummy_publisher": false,
                    "notify_joining": false,
                    "audiocodec": "opus",
                    "videocodec": "vp8",
                    "opus_fec": true,
                    "record": false,
                    "lock_record": false,
                    "num_participants": 0,
                    "audiolevel_ext": true,
                    "audiolevel_event": false,
                    "videoorient_ext": true,
                    "playoutdelay_ext": true,
                    "transport_wide_cc_ext": true
                }
            ]
        }
    }

THen I using join request with body like this:

join params {
  janus: 'message',
  plugin: 'janus.plugin.videoroom',
  session_id: 8568607942621781,
  handle_id: 3267543887867048,
  transaction: 'VeENHRbBTHWI',
  body: { request: 'join', room: 11, ptype: 'publisher', display: 'test' }
}

But the response is ack only, I dont know why it's not return joined event, can someone help?

{
    "janus": "ack",
    "session_id": 8568607942621781,
    "transaction": "VeENHRbBTHWI"
}

Note that after this, I checked the participants inside room but it's still empty:

{
    "janus": "success",
    "session_id": 4397550774641519,
    "transaction": "h8LgvUJxVXGk",
    "sender": 8580331991428173,
    "plugindata": {
        "plugin": "janus.plugin.videoroom",
        "data": {
            "videoroom": "participants",
            "room": 11,
            "participants": []
        }
    }
}

All my https call work nomally(such as create video room/ destroy, listroom, list participants,...) but only joinroom api have trouble, here is my javascript code:

joinRoom = async(options) => {
        await this.ensureAttachedToSessionId()
        const promise = new Promise((resolve, reject) => {
            const params = {
                janus: 'message',
                plugin: this.plugin,
                session_id: this.sessionID,
                handle_id: this.handleID,
                transaction: JanusUtils.randomString(12),
                body: {
                    request: 'join',
                    ...options
                }
            }
            console.log('join params', params)
            fetch(this.janusUrl, {
                method: 'POST',
                body: JSON.stringify(params),
                ...JanusUtils.defaultHeader()
            }).then(result => result.json())
            .then(result => {
                resolve(result) 
            })
            .catch(error => { reject(error) })
        })
        return promise
    }

Answer 1

Once you get that "ack" response you can use GET /janus/12345678 endpoint to get the "joined" event you expect. 12345678 - is your session ID. This is because requests like "join" are async. This what the docs say.

The join , joinandconfigure , configure , publish , unpublish , start , pause , switch and leave requests instead are all asynchronous, which means you'll get a notification about their success or failure in an event. You can heck it out at https://janus.conf.meetecho.com/docs/videoroom

Also check this article https://janus.conf.meetecho.com/docs/rest.htm. This is shows how to use Janus REST API

You can establish a long polling request to poll for events. However, I would recomment to take a look on Janode. https://github.com/meetecho/janode. It has great examples built in JS.