Event Emitter in Angular Not in AngularJs!

"EventEmitter" is used in Angular, starting from version 2 and later.

In Angular, EventEmitter is a class provided by the @angular/core module, and it is used to create custom events that can be emitted from components and listened to by other components. It plays a crucial role in the parent-child communication or component interaction within an Angular application.

Here's how you can use EventEmitter in Angular:

1. Import EventEmitter: You need to import EventEmitter from @angular/core at the beginning of your component file where you want to use it.

   import { EventEmitter } from '@angular/core';

1. Declare an EventEmitter Property: Inside your component class, you declare an EventEmitter property. You can specify the event type as a generic parameter, indicating what kind of data the event will emit.

   myEvent = new EventEmitter<string>();

1. Emitting an Event: To emit an event, you can call the emit method on your EventEmitter instance and pass the data you want to emit. For example:

   this.myEvent.emit('Data to send to other components');

1. Listening to the Event: In another component or the parent component, you can subscribe to the event using the (eventEmitterName) syntax in the component's template. For example:

   <app-child (myEvent)="handleEvent($event)"></app-child>

Here, when the "myEvent" event is emitted in the app-child component, the handleEvent method in the parent component will be called with the emitted data.

1. Handling the Event: In the parent or listening component, you define a method that will be executed when the event is emitted. In the example above, handleEvent($event) is the method that handles the emitted event. You can access the emitted data via the $event parameter.

By using EventEmitter, you can establish communication between components in your Angular application, enabling parent-child or custom component interaction. It's a way to implement a publish-subscribe mechanism within your application, allowing components to notify and react to events without direct coupling.