What is Event and Event Emitter in Node JS
- An User Action i.e click
- Event names are defined simply by calling .emit with the event name.
- An object sends events using the .emit function.
- Events are sent to any listeners that have registered to receive events from the object.
- The program registers to receive an event by calling that object’s .on method, giving the event name and an event handler function.
How to Send Data using Emit Method
- it is required to send data along with an event. To do so, simply add the data as arguments to the .emit call
- this.emit(‘eventName’, data1, data2, ..);
Example
var events = require('events');
var eventEmitter = new events.EventEmitter();
var myfun = function (data) {
console.log('Something happen!' +data );
}
eventEmitter.on('Hello', myfun);
eventEmitter.emit('Hello','this is my data');
Output
