Check guard on multiple values via ngrx select

Question

I have a canActivate ( guard ) where I am checking the loaded variable to see if the queue has loaded or not.

However I now need to check multiple queue loaded variable ( boolean ) to see if they have all loaded or not. I will need to dispatch actions then.

canActivate(): Observable < boolean > {
  return this.checkStore().pipe(
    switchMap(() => of(true)),
    catchError(() => of(false))
  );
}

checkStore(): Observable < boolean > {
  //   Below are the additional booleans I need to check on
  //  this.store.select(fromStore.isFirstQueueLoaded);
  //  this.store.select(fromStore.isSecondQueueLoaded);
  //  this.store.select(fromStore.isThirdQueueLoaded);
  //  this.store.select(fromStore.isFourthQueueLoaded);
  //  this.store.select(fromStore.isFifthQueueLoaded);
  //  this.store.select(fromStore.isSixthQueueLoaded);
  //  this.store.select(fromStore.isSeventhQueueLoaded);


  return this.store.select(fromStore.isFirstQueueLoaded)
    // want to check for remaining queues loaded boolean val here
    .pipe(
      tap(loaded => {
        // need to check for loaded values of all queues
        if (!loaded) {
          this.dispatchActiontoStoreForAllQueue();
        }
      }),
      filter(loaded => loaded)
    );
}

dispatchActiontoStoreForAllQueue(): void {
  this.store.dispatch(new fromStore.LoadFirstQueue({}));
  this.store.dispatch(new fromStore.LoadSecondQueue({}));
  this.store.dispatch(new fromStore.LoadthirdQueue({}));
  this.store.dispatch(new fromStore.LoadFourthQueue({}));
  this.store.dispatch(new fromStore.LoadFifthQueue({}));
  this.store.dispatch(new fromStore.LoadSixthQueue({}));
  this.store.dispatch(new fromStore.LoadSeventhQueue({}));
}

How do we combine all of these NGRX selects ( optimized approach ) to check on their booleans and activate the guard?

Teddy Sterne Teddy Sterne · Accepted Answer · 2018-06-28T19:42:32

I would create one selector instead of seven different ones. This would look something like:

export const fromStore = {
  areAllQueuesLoaded: createSelector(selectAppState, (state: AppState) => {
    return state.queue1.isLoaded &&
           state.queue2.isLoaded &&
           state.queue3.isLoaded &&
           state.queue4.isLoaded &&
           state.queue5.isLoaded &&
           state.queue6.isLoaded &&
           state.queue7.isLoaded;
  }),
}

And then in your component you only need one select:

return this.store.select(fromStore.areAllQueuesLoaded).subscribe(loaded => {   
    this.dispatchActiontoStoreForAllQueue();
});

Check guard on multiple values via ngrx select

1 Answers