Skip to main content
Version: 2.0.x

PubSub - iOS

PubSub feature allows the participant to send and receive messages of the topics which he has subscribed.

Methods

publish()

This method is use for publishing message of specific topic.

Syntax

func publish(topic: String, message: String, options: [String : Any] = [:])
Parameter NameTypeDescription
topicStringThis should be the topic for which you are publishing a message.
messageStringThis is the actual message, which will be published to participants, who had subscribed to a particular topic.
optionsObjectThis is the object which provides an option, such as persist, which persists message history for upcoming participants.

Example

func sendMessage() {
meeting.pubsub.publish(topic: "CHAT", message: "Hello Everyone!", options: ["persist": true])
}

subscribe()

This method is used to subscribe for particular topic. This method returns a list of messages which were sent earlier.

Syntax

func subscribe(topic: String, forListener listener: PubSubMessageListener)
Parameter NameTypeDescription
topicStringThis should be the topic to be subscribed.
forListenerPubSubMessageListenerThis is an object of PubSubMessageListener, which listens for upcoming messages and calls onMessageReceived function, when new message received.

Example

class ChatMessageListener: PubSubMessageListener {
func onMessageReceived(_ message: PubSubMessage) {
// Print new message
print("Message Received:= " + message.message)
}
}
const listener = ChatMessageListener()

func subscribe() {
// Subscribe 'CHAT' topic
meeting?.pubsub.subscribe(topic: "CHAT", forListener: listener)
}

unsubscribe()

This method is used to unsubscribe the message topic.

Syntax

func unsubscribe(topic: String, forListener listener: PubSubMessageListener)
Parameter NameTypeDescription
topicStringThis should be the topic to be unsubscribed.
forListenerPubSubMessageListenerThis is an object of PubSubMessageListener, which was passed in subscribe().

Example

func unsubscribe() {
// Unsubscribe 'CHAT' topic
meeting?.pubsub.unsubscribe(topic: "CHAT", forListener: listener)
}

Sample Code

import UIKit
import VideoSDKRTC

class ChatViewController: UIViewController {

// Meeting
public var meeting: Meeting

// Chat Topic
var topic: String = "CHAT"

var chatMessageListener: ChatMessageListener = ChatMessageListener()

init(meeting: Meeting) {
self.meeting = meeting;

// Subscribe 'CHAT' topic
meeting.pubsub.subscribe(topic: topic, forListener: chatMessageListener)

// Get persisted chat messages
let pubsubMessages = meeting.pubsub.getMessagesForTopic(topic)

for msg in pubsubMessages! {
print("Message: " + msg.message)
}

super.init(nibName: nil, bundle: nil)
}

override func viewDidLoad() {
super.viewDidLoad()
}

required init?(coder: NSCoder) {
fatalError("Fatal Error")
}


// Lifecycle
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
meeting.pubsub.publish(topic: topic, message: "Hii from iOS", options: ["persist": true])
print("Chat Message Published")
}

override func viewDidDisappear(_ animated: Bool) {
super.viewDidDisappear(animated)
meeting.pubsub.unsubscribe(topic: topic, forListener: chatMessageListener)
print("Unsubscribed 'CHAT' topic")
}
}

class ChatMessageListener: PubSubMessageListener{
func onMessageReceived(_ message: PubSubMessage){
print("Message Received: " + message.message)
}
}

Got a Question? Ask us on discord