Animation Callbacks in Angular

We’ve touched on the basics of animation in Angular, so let’s now explore another feature of the animation system: animation callbacks. You can use the start and done callbacks to setup hook methods that get called at the start or end of animations.

Let’s start with markup like this, where our animation trigger is called itemAnim:

<ul *ngIf="items">
  <li *ngFor="let item of items"
      (click)="removeItem(item)"
      [@itemAnim]>{{ item }}</li>
</ul>

We can add callbacks with the following syntax:

<ul *ngIf="items">
  <li *ngFor="let item of items"
      (click)="removeItem(item)"
      [@itemAnim]
      (@itemAnim.start)="animStart($event)"
      (@itemAnim.done)="animEnd($event)">{{ item }}</li>
</ul>

The callbacks receive an AnimationTransitionEvent event that contains the following properties: fromState, phaseName (“start” or “done”), toState and totalTime.

In the component we can now define the callback methods:

// ...

animStart(event) {
  console.log('Animation Started');
  // do more stuff
}

animEnd(event) {
  console.log('Animation Ended');
  // do more stuff
}