app.effects.ts

export interface RegisterEffects { ngRegisterEffects(): void; }

export const EFFECTS_CLASS = new InjectionToken<RegisterEffects[]>('EFFECTS_CLASS');

export function EffectsProvider<T extends RegisterEffects>(
  effectsClass: Type<T>): ClassProvider {
  return {
    multi: true,
    provide: EFFECTS_CLASS,
    useClass: effectsClass
  };
}

export function getEffectProviders() {
  return [
    // For each module we need to get its effects class
    // and return it as a injectable. Also in the `ngDoBootstrap`
    // wee need to call its method `ngRegisterEffects`.
    EffectsProvider(EventsEffects)
  ];
}