effects.ts

import { Injectable } from '@angular/core';
import { Actions, Effect, ofType } from '@ngrx/effects';
import { DarsActionTypes } from '@app/dars/store/actions';
import * as darsActions from '@app/dars/store/actions';
import { flatMap, map, catchError } from 'rxjs/operators';
import { DarsApiService } from '../services/api.service';
import { of } from 'rxjs';

@Injectable()
export class DARSEffects {
  constructor(private actions$: Actions, private api: DarsApiService) {}

  @Effect()
  load$ = this.actions$.pipe(
    ofType(DarsActionTypes.StartLoadingMetadata),
    flatMap(() => this.api.getAudits()),
    map(metadata => new darsActions.AddAuditMetadata({ metadata })),
    catchError(() => {
      return of(
        new darsActions.ErrorLoadingMetadata({
          message: 'Unable to load audit metadata. Please try again',
        }),
      );
    }),
  );
}