Question

How to create and fire event with arguments in Node.js

Answer 1

const events = require('events');
const eventEmitter = new events.EventEmitter();
 
// Register (add) a listener
eventEmitter.on('gonodego', function(arg) {
    console.log(arg);
});
 
// Fire (Raise) an event with arguments:
eventEmitter.emit('gonodego', { id: 88622, name: 'Elizabeth' });
   
  
   
/*
run:
   
{ id: 88622, name: 'Elizabeth' }
   
*/

 

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Answer 2

const events = require('events');
const eventEmitter = new events.EventEmitter();
 
// Register (add) a listener
eventEmitter.on('gonodego', arg => {
    console.log(arg);
});
 
// Fire (Raise) an event with arguments:
eventEmitter.emit('gonodego', { id: 88622, name: 'Elizabeth' });
   
  
   
/*
run:
   
{ id: 88622, name: 'Elizabeth' }
   
*/

 

Cleaner teeth, healthier you!
Get The Secret to a Bright and Healthy Smile

Answer 3

// The module: log.js

const events = require('events');

class Log extends events {
   show(s) {
     console.log(s);
  
     // Fire (Raise) an event with arguments:
     this.emit('gonodego', { id: 88622, name: 'Elizabeth' });
  }
}

module.exports = Log;

// The application: app.js

const Log = require('./log');
const log = new Log();   

// Register (add) a listener
log.on('gonodego', arg => {
    console.log(arg);
});

log.show('node.js');




/*
run:
   
node.js
{ id: 88622, name: 'Elizabeth' }
   
*/

 

Cleaner teeth, healthier you!
Get The Secret to a Bright and Healthy Smile