Ngrx Store, Effects, Http Ajax Configuring Polling on Angular 2

Question

I am building an Ngrx Angular 2 application and trying to get my HTTP calls to continue polling over a period of time. I saw the use of the function interval(), but in the case of Ngrx, when service calls are made internally @Effect(), this gives an error. Please inform:

@Injectable()
export class TasksEffects {
constructor(
    private actions$: Actions,
    private TS: TaskService
){}

@Effect()
onLoadTasksLoadTasks$: Observable<Action> = this.actions$.ofType(tasksActions.ActionTypes.LOAD_TASKS)
    .switchMap(() => {
        return this.TS.index()
            .map((res) => new tasksActions.LoadTasksSuccessAction(res.json()))
            .catch(err => of(new tasksActions.LoadTasksFailAction(err)));
    });

I want to run the switchMap function every ten seconds. This does not work.

    @Effect()
onLoadTasksLoadTasks$: Observable<Action> = this.actions$.ofType(tasksActions.ActionTypes.LOAD_TASKS)
    .switchMap(() => {
        return this.TS.index()
            .map((res) => new tasksActions.LoadTasksSuccessAction(res.json()))
            .catch(err => of(new tasksActions.LoadTasksFailAction(err)));
    }).interval(10000);

Type error:

Answer 1

As indicated in another answer, it intervalis a static function, so it does not exist on the prototype Observable, which is why your error is executed.

, , timer.

import { Observable } from 'rxjs/Observable';
import 'rxjs/add/observable/of';
import 'rxjs/add/observable/timer';
import 'rxjs/add/operator/catch';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/switchMap';

@Effect()
onLoadTasksLoadTasks$: Observable<Action> = this.actions$
  .ofType(tasksActions.ActionTypes.LOAD_TASKS)
  .switchMap(() => Observable
    .timer(0, 10000)
    .switchMap(() => this.TS.index()
      .map((res) => new tasksActions.LoadTasksSuccessAction(res.json()))
      .catch(err => Observable.of(new tasksActions.LoadTasksFailAction(err)))
    )
  );

timer , , . , LOAD_TASKS, switchMap , timer ..

Answer 2

rxjs 5 interval() . Observable.interval(1).

.

this.actions$.ofType(tasksActions.ActionTypes.LOAD_TASKS)
  .skipUntil(Observable.interval(10000))
  .switchMap(res => {...})