Difference between EventEmitter.next() and EventEmitter.emit() in Angular 2

Question

What is the difference between EventEmitter.emit() and EventEmitter.next()? Both dispatching the event to the subscribed listeners.

Answer 1

In the latest version(Ng9), the source code of event_emitter.ts goes as following:

export class EventEmitter<T extends any> extends Subject<T> {
  /**
   * Emits an event containing a given value.
   * @param value The value to emit.
   */
  emit(value?: T) { super.next(value); }
}

EventEmitter extends from parent class Subject. And emit method call super.next() as you may expected.

Answer 2

They do the same. emit() is the current version, next() is deprecated.

See also https://github.com/angular/angular/blob/b5b6ece65a96f5b8f134ad4899b56bf84afe3ba0/modules/angular2/src/facade/async.dart#L49