Node.js, MongoDB, and AngularJS Web Development

Implementing Event Emitters and Listeners

In the following chapters, you have opportunities to implement a lot of the events that are built into the various Node.js modules. This section focuses on creating your own custom events as well as implementing listener callbacks that are implemented when an event is emitted.

Adding Custom Events to Your JavaScript Objects

Events are emitted using an EventEmitter object. This object is included in the events module. The emit(eventName, [args]) function triggers the eventName event and includes any arguments provided. The following code snippet shows how to implement a simple event emitter:

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var events = require('events');var emitter = new events.EventEmitter();emitter.emit("simpleEvent"); ...