The MessageChannel.postMessage() method is an inbuilt application programming interface of class Worker within worker_threads module which is used to send the message from one port to another.
Syntax:
const MessageChannel.postMessage(value[, transferList])
Parameters: This method takes the value as a parameter which can contain any kind of object.
Return Value: This method sends the message from one port to another.
Example 1: Filename: index.js
// Node.js program to demonstrate the
// MessageChannel.postMessage() method
// Importing worker_thread module
const { MessageChannel, receiveMessageOnPort }
= require('worker_threads');
// Creating and initializing the MessageChannel
const { port1, port2 } = new MessageChannel();
// Sending data to port 2
// by using postMessage() method
port1.postMessage({ hello: 'world1' });
// Posting data in port 1
// by using postMessage() method
port2.postMessage({ hello: 'world2' });
/// Display the result
console.log("received data in port1 : ");
console.log(receiveMessageOnPort(port1));
console.log("received data in port2 : ");
console.log(receiveMessageOnPort(port2));
// Closing the ports
port1.close();
port2.close();
Output:
received data in port1 :
{ message: { hello: 'world2' } }
received data in port2 :
{ message: { hello: 'world1' } }
Example 2: Filename: index.js
// Node.js program to demonstrate the
// MessageChannel.postMessage() method
// Importing worker_thread module
const { MessageChannel, receiveMessageOnPort }
= require('worker_threads');
// Creating and initializing the MessageChannel
const { port1, port2 } = new MessageChannel();
// Catching the event message
port2.on('message', (message) => console.log(message));
// Catching the event close
port2.on('close', () => console.log('closed!'));
// Sending message to port2
// by using postMessage() method
port1.postMessage('GFG');
// Closing port by using
// close() method
port1.close();
Output:
GFG closed!
Run the index.js file using the following command:
node index.js