Participant Manager

Getting started

Spark AR project setup

You need AR Studio version to be >133 to use this library.

1. Download Spark AR Studio.
2. Open your project in Spark AR Studio.
3. Open the AR Library from within the Assets panel and select the Script Packages tab.
4. Search the "spark-ar-participant-manager" and import to the project.
5. If you hasn't used multipeer and participants capability, please manually enable them.

Loading the module

To use it, import it via

import {createParticipantManager} from 'spark-ar-participant-manager';

And call in your main script body to initialise it

const participantManager = await createParticipantManager();

Documentation

activeParticipants: array<Participant>

activeParticipants contains all participants that are online and in same effect(include self), and stable sorted with their id.

Diagnostics.log(participantManager.activeParticipants.length)
Diagnostics.log(participantManager.activeParticipants[0].id)

Anytime a new active participant joined, no matter it's new participant joining the call or a participant joining the same effect, an event "join" will be emmited.

Anytime a active participant left, no matter it's leaving the call or opting out the same effect, an event "leave" will be emmited.

See Add event listener

currentHost: Participant

This returns an active participant as host, you can use it to check and only run certain logic only on host user. The host may change when activeParticipants changed, you can listen to "hostChange" event to know that.

(See Add event listener)

Diagnostics.log(participantManager.currentHost.id)

selfIndex: number

selfIndex provides the index of self in the activeParticipants

Diagnostics.log(participantManager.activeParticipants[participantManager.selfIndex].id === participantManager.self.id)

peerIndices: array<number>

peerIndices provides the index of each peer in the activeParticipants, if the peer is not active, the correspond array element value will be -1.

Here peer is the same order as Participants.getAllOtherParticipants

Add Event Listener

addListener(eventType: string, callback: Participant => void)

removeListener(eventType: string, callback: Participant => void)

You can add/remove event listener, the events are:

• "join": when a new active participant joined
• "leave": when an active participant left
• "hostChange": when currentHost changed

function joinCallback(participant) {
  Diagnostics.log(participant.id)
}
participantManager.addListener('join', joinCallback)

// remove
participantManager.removeListener('join', joinCallback)

Participant Message Channel

getMessageChannel(topic: string): ParticipantMessageChannel

ParticipantMessageChannel provides a wrapper on multipeer message channel, that you can send message to specific participant.

You can call sendMessage(participantId: string, message: object, realTimeChannel: boolean): Promise<void> to send message to certain participant, only that participant will receive message. If provided null for the participantId, then it's a broadcast message like normal message channel.

You can call subscribeToMessage(callback: (from: string, message: object) => void) to subscribe to message. Example:

const secretChannel = participantManager.getMessageChannel('secret');
secretChannel.sendMessage(target.id, {text: 'Hello!'});

secretChannel.subscribeToMessage((from, message) => {
  Diagnostics.log("Receive from " + from + '\n says ' + message.text);
});

License

The Participant Manager library is MIT licensed.