client/src/app/videos/recommendations/recommended-videos.store.ts

   1 import { Inject, Injectable } from '@angular/core'
   2 import { Observable, ReplaySubject } from 'rxjs'
   3 import { Video } from '@app/shared/video/video.model'
   4 import { RecentVideosRecommendationService } from '@app/videos/recommendations/recent-videos-recommendation.service'
   5 import { RecommendationService, UUID } from '@app/videos/recommendations/recommendations.service'
   6 import { map, switchMap, take } from 'rxjs/operators'
   7
   8 /**
   9  * This store is intended to provide data for the RecommendedVideosComponent.
  10  */
  11 @Injectable()
  12 export class RecommendedVideosStore {
  13   public readonly recommendations$: Observable<Video[]>
  14   public readonly hasRecommendations$: Observable<boolean>
  15   private readonly requestsForLoad$$ = new ReplaySubject<UUID>(1)
  16
  17   constructor (
  18     @Inject(RecentVideosRecommendationService) private recommendations: RecommendationService
  19   ) {
  20     this.recommendations$ = this.requestsForLoad$$.pipe(
  21       switchMap(requestedUUID => recommendations.getRecommendations(requestedUUID)
  22         .pipe(take(1))
  23       ))
  24     this.hasRecommendations$ = this.recommendations$.pipe(
  25       map(otherVideos => otherVideos.length > 0)
  26     )
  27   }
  28
  29   requestNewRecommendations (videoUUID: string) {
  30     this.requestsForLoad$$.next(videoUUID)
  31   }
  32 }