how to apply different animation between different route in angular 2

Question

I have a test app build with angular 2, I have successfully applied one animation between route change

state('default', style({
    opacity: 1,
    transform: 'scale(1) translateY(0)'
})),
transition('void <=> default', [
    style({ opacity: 0, transform: 'scale(.9) translateY(-20px)' }),
    animate('.2s')
])

But I also want a different animation when a list page change to an item page, like click a hero inside a hero-list, so I did this

state('childActivate', style({
    opacity: 1,
    transform: 'scale(1) translateY(0)'
})),
transition('childActivate => void', [
    animate('1.2s', style({
        transform: 'scale(0.9)  translateY(-120px)',
        opacity: 0
    }))
])

I tried to set the state to 'childActivated' after i click on an item and before navigation:

onHeroSelected(heroEvent: Hero) {
    this.animState = "childActivate";
    this.router.navigate(['/hero-detail', heroEvent.id]);
}

but has no effect.

How can I get multiple animations between route?

Answer 1

Setting the state to "childActivate" has no effect, because the component is being destroyed within the next change detection step, so state switches to void instead.

This is how i solved this issue: I delay the route change by 1 further change detection cycle. I use a CanDeactivate Guard for this, which listens for a promise to resolve.

Check out my plnkr: https://embed.plnkr.co/cOeDfXCetaYuXFaZ7WeO/

Within route definitions i add:

canDeactivate: [CanDeactivateAfterChangeDetectionGuard]

This is the CanDeactivate Guard:

@Injectable()
class CanDeactivateAfterChangeDetectionGuard implements CanDeactivate<WaitForChangeDetection> {
  canDeactivate(component: WaitForChangeDetection): Promise<boolean> {
    return component.waitForChangeDetection();
  }
}

which works with any component implementing this interface:

declare abstract class WaitForChangeDetection {
  abstract waitForChangeDetection(): Promise<boolean>;
}

I created a base component with a default implementation of this interface

@Component({})
class WaitForChangeDetectionImpl implements AfterViewChecked, WaitForChangeDetection {
  constructor(private cdRef: ChangeDetectorRef){
    this.viewChecked$ = new Subject<void>();
  }

  viewChecked$: Subject<void>;
  waitForChangeDetection(): Promise<boolean>{
    this.cdRef.detectChanges();
    return new Promise((resolve) => this.viewChecked$.subscribe(() => resolve(true)));
  }

  ngAfterViewChecked(){
    this.viewChecked$.next();
  }
}

So you can extend this component to provide the functionality to work with the guard for any component.

@Component({})
class ComponentA extends WaitForChangeDetectionImpl {
...