Emitter in Node - Revision history

AliIybar: /* App.js */

2018-12-12T10:57:31Z

‎App.js

AliIybar: /* Logger.js */

2018-12-12T10:56:18Z

‎Logger.js

AliIybar at 09:08, 15 September 2018

2018-09-15T09:08:56Z

AliIybar at 09:07, 15 September 2018

2018-09-15T09:07:48Z

AliIybar at 20:45, 13 September 2018

2018-09-13T20:45:21Z

AliIybar at 20:38, 13 September 2018

2018-09-13T20:38:44Z

AliIybar: Created page with "Category:Node

 const EventEmitter = require('events'); const emitter = new EventEmitter();  //Register a listener  emitter.on('messageLogged', func..."

2018-09-13T20:33:16Z

Created page with "Category:Node <pre class="brush:js;"> const EventEmitter = require('events'); const emitter = new EventEmitter(); //Register a listener emitter.on('messageLogged', func..."

New page

[[Category:Node]]

<pre class="brush:js;">
const EventEmitter = require('events');
const emitter = new EventEmitter();

//Register a listener
emitter.on('messageLogged', function(){
console.log('Listener called');
});

// Raise an event
emitter.emit('messageLogged');

</pre>

@@ Line 42: / Line 42: @@
    log(message){
       console.log(message);
+   }
 };
@@ Line 47: / Line 48: @@
 module.exports = Logger;
 </pre>
 === App.js ===
 <pre class="brush:js;">

@@ Line 1: / Line 1: @@
 [[Category:Node.js]]
+== Sample Code ==
 <pre class="brush:js;">
 const EventEmitter = require('events');

← Older revision		Revision as of 09:07, 15 September 2018
Line 33:		Line 33:

	emitter.emit('messageLogged', {id:1, url:'http://...'});		emitter.emit('messageLogged', {id:1, url:'http://...'});
		+	</pre>
		+	== Using in a Class ==
		+	=== Logger.js ===
		+	<pre class="brush:js;">
		+	const EventEmitter = require('events');
		+	class Logger extends EventEmitter {
		+
		+	log(message){
		+	console.log(message);
		+	}
		+	};
		+
		+	module.exports = Logger;
		+	</pre>
		+	=== App.js ===
		+	<pre class="brush:js;">
		+	const EventEmitter = require('events');
		+	const logger = new Logger();
		+
		+	//Register a listener
		+	logger.on('messageLogged', (arg) => {
		+	console.log('Listener called', arg);
		+	});
		+	logger.log('message');
	</pre>		</pre>

← Older revision		Revision as of 20:45, 13 September 2018
Line 1:		Line 1:
−	[[Category:Node]]	+	[[Category:Node.js]]

	<pre class="brush:js;">		<pre class="brush:js;">

← Older revision		Revision as of 20:38, 13 September 2018
Line 13:		Line 13:
	emitter.emit('messageLogged');		emitter.emit('messageLogged');

		+	</pre>
		+
		+	Registration must come before raising
		+
		+	=== Event Arguments ===
		+	<pre class="brush:js;">
		+	emitter.on('messageLogged', function(arg){
		+	console.log('Listener called', arg);
		+	});
		+
		+	emitter.emit('messageLogged', {id:1, url:'http://...'});
		+	</pre>
		+
		+	==== Arrow Function ====
		+	<pre class="brush:js;">
		+	emitter.on('messageLogged',(arg) => {
		+	console.log('Listener called', arg);
		+	});
		+
		+	emitter.emit('messageLogged', {id:1, url:'http://...'});
	</pre>		</pre>