Video SDK usePubSub Hook

usePubSub Hook

usePubSub takes all the properties and events as parameters and returns all the properties and methods to work pubsub instance.

usePubSub example

usePubSub react hook

import { usePubSub } from "@videosdk.live/react-sdk";

var topic = "CHAT";

function onMessageReceived(message) {
  console.log("New Message:", message);
}

function onOldMessagesReceived(messages) {
  console.log("Old Messages:", messages);
}

const { publish, messages } = usePubSub(topic, {
  onMessageReceived,
  onOldMessagesReceived,
});

Parameters

topic

• type : String

• Represents the topic for which you are publishing and getting a message.

---

onMessageReceived

• onMessageReceived() will be triggered when a new message is published for the subscribed topic with the message object.

---

onOldMessagesReceived

• onOldMessagesReceived() will be triggered once when you subscribe to the topic and will receive all the old messages present for that topic as an array of message object.

• message published with persist as true will only be available through this callback.

---

Returns

publish()

• publish() is used to publish the the message for the the particular topic.

Parameters

message

• type : String

• Message that has been published on the specific topic.

---

options

• type : Object

• This is an object, which provides an option, such as persist, which persists message history for upcoming participants if provide persist: true.

---

Example

const { publish, messages } = usePubSub("CHAT");

const sendMessage = (message) => {
  publish(message, { persist: true });
};

sendMessage("Hello");

---

messages

• messages is an array of message objects which will hold all the persisted messages.

Message Object

{
  id: String,
  message: String,
  senderId: String,
  senderName: String,
  timestamp: String,
  topic: String
}