![]() I've tried an alternative event library - EventEmitter3 which has a support for custom context for events (class context can be passed as third parameter to the addListener function ( ("test", this.handleTestEvent, this), it works perfectly, but I rather want to use the included EventEmitter from Node.js. In short, the events provide easy to use customization points for the clients. It will be called to execute when an event occurs. Listener In the NodeJS, the Listener is a function. The above example was based on an instance of EventEmitter how do we create classes that extend EventEmitter Node. By sending the events at the key points in our program execution, we let the clients add their custom logic externally at those points. Module events provides you with an EventEmitter class, that is a central class in the NodeJS, assisting in defining an event, registering Listeners of this event, and emitting (emit) the event. EventEmitter is what makes it possible to write amazing libraries for Node.js. Both functions return emitter, so calls can be chained. ![]() handleTestEvent method has access to the class context using this, but listener cannot be removed (there is no reference to the bounded listener as in example 2). The Event Emitters allows us to build highly customizable components. Multiple calls to the same event and listener will add the listener multiple times and correspondingly fire multiple times. ![]() In this example, I'm using an arrow function to preserve a context of the class in the event listener. ![]() Is there a way to access to the class context in the event listener method with possibility to remove the listener?Įxample 1: import from "events" These are treated as special cases within Node.js. ![]()
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