client/src/app/shared/video/abstract-video-list.ts

   1 import { ElementRef, OnDestroy, OnInit, ViewChild } from '@angular/core'
   2 import { ActivatedRoute, Router } from '@angular/router'
   3 import { isInMobileView } from '@app/shared/misc/utils'
   4 import { InfiniteScrollerDirective } from '@app/shared/video/infinite-scroller.directive'
   5 import { NotificationsService } from 'angular2-notifications'
   6 import 'rxjs/add/operator/debounceTime'
   7 import { Observable } from 'rxjs/Observable'
   8 import { fromEvent } from 'rxjs/observable/fromEvent'
   9 import { Subscription } from 'rxjs/Subscription'
  10 import { AuthService } from '../../core/auth'
  11 import { ComponentPagination } from '../rest/component-pagination.model'
  12 import { SortField } from './sort-field.type'
  13 import { Video } from './video.model'
  14
  15 export abstract class AbstractVideoList implements OnInit, OnDestroy {
  16   private static LINES_PER_PAGE = 4
  17
  18   @ViewChild('videosElement') videosElement: ElementRef
  19   @ViewChild(InfiniteScrollerDirective) infiniteScroller: InfiniteScrollerDirective
  20
  21   pagination: ComponentPagination = {
  22     currentPage: 1,
  23     itemsPerPage: 10,
  24     totalItems: null
  25   }
  26   sort: SortField = '-createdAt'
  27   defaultSort: SortField = '-createdAt'
  28   syndicationItems = []
  29
  30   loadOnInit = true
  31   pageHeight: number
  32   videoWidth: number
  33   videoHeight: number
  34   videoPages: Video[][] = []
  35
  36   protected baseVideoWidth = 215
  37   protected baseVideoHeight = 230
  38
  39   protected abstract notificationsService: NotificationsService
  40   protected abstract authService: AuthService
  41   protected abstract router: Router
  42   protected abstract route: ActivatedRoute
  43   protected abstract currentRoute: string
  44   abstract titlePage: string
  45
  46   protected loadedPages: { [ id: number ]: Video[] } = {}
  47   protected otherRouteParams = {}
  48
  49   private resizeSubscription: Subscription
  50
  51   abstract getVideosObservable (page: number): Observable<{ videos: Video[], totalVideos: number}>
  52   abstract generateSyndicationList ()
  53
  54   get user () {
  55     return this.authService.getUser()
  56   }
  57
  58   ngOnInit () {
  59     // Subscribe to route changes
  60     const routeParams = this.route.snapshot.queryParams
  61     this.loadRouteParams(routeParams)
  62
  63     this.resizeSubscription = fromEvent(window, 'resize')
  64       .debounceTime(500)
  65       .subscribe(() => this.calcPageSizes())
  66
  67     this.calcPageSizes()
  68     if (this.loadOnInit === true) this.loadMoreVideos(this.pagination.currentPage)
  69   }
  70
  71   ngOnDestroy () {
  72     if (this.resizeSubscription) this.resizeSubscription.unsubscribe()
  73   }
  74
  75   onNearOfTop () {
  76     this.previousPage()
  77   }
  78
  79   onNearOfBottom () {
  80     if (this.hasMoreVideos()) {
  81       this.nextPage()
  82     }
  83   }
  84
  85   onPageChanged (page: number) {
  86     this.pagination.currentPage = page
  87     this.setNewRouteParams()
  88   }
  89
  90   reloadVideos () {
  91     this.loadedPages = {}
  92     this.loadMoreVideos(this.pagination.currentPage)
  93   }
  94
  95   loadMoreVideos (page: number) {
  96     if (this.loadedPages[page] !== undefined) return
  97
  98     const observable = this.getVideosObservable(page)
  99
 100     observable.subscribe(
 101       ({ videos, totalVideos }) => {
 102         // Paging is too high, return to the first one
 103         if (this.pagination.currentPage > 1 && totalVideos <= ((this.pagination.currentPage - 1) * this.pagination.itemsPerPage)) {
 104           this.pagination.currentPage = 1
 105           this.setNewRouteParams()
 106           return this.reloadVideos()
 107         }
 108
 109         this.loadedPages[page] = videos
 110         this.buildVideoPages()
 111         this.pagination.totalItems = totalVideos
 112
 113         // Initialize infinite scroller now we loaded the first page
 114         if (Object.keys(this.loadedPages).length === 1) {
 115           // Wait elements creation
 116           setTimeout(() => this.infiniteScroller.initialize(), 500)
 117         }
 118       },
 119       error => this.notificationsService.error('Error', error.message)
 120     )
 121   }
 122
 123   protected hasMoreVideos () {
 124     // No results
 125     if (this.pagination.totalItems === 0) return false
 126
 127     // Not loaded yet
 128     if (!this.pagination.totalItems) return true
 129
 130     const maxPage = this.pagination.totalItems / this.pagination.itemsPerPage
 131     return maxPage > this.maxPageLoaded()
 132   }
 133
 134   protected previousPage () {
 135     const min = this.minPageLoaded()
 136
 137     if (min > 1) {
 138       this.loadMoreVideos(min - 1)
 139     }
 140   }
 141
 142   protected nextPage () {
 143     this.loadMoreVideos(this.maxPageLoaded() + 1)
 144   }
 145
 146   protected buildRouteParams () {
 147     // There is always a sort and a current page
 148     const params = {
 149       sort: this.sort,
 150       page: this.pagination.currentPage
 151     }
 152
 153     return Object.assign(params, this.otherRouteParams)
 154   }
 155
 156   protected loadRouteParams (routeParams: { [ key: string ]: any }) {
 157     this.sort = routeParams['sort'] as SortField || this.defaultSort
 158
 159     if (routeParams['page'] !== undefined) {
 160       this.pagination.currentPage = parseInt(routeParams['page'], 10)
 161     } else {
 162       this.pagination.currentPage = 1
 163     }
 164   }
 165
 166   protected setNewRouteParams () {
 167     const routeParams = this.buildRouteParams()
 168     this.router.navigate([ this.currentRoute ], { queryParams: routeParams })
 169   }
 170
 171   protected buildVideoPages () {
 172     this.videoPages = Object.values(this.loadedPages)
 173   }
 174
 175   protected buildVideoHeight () {
 176     // Same ratios than base width/height
 177     return this.videosElement.nativeElement.offsetWidth * (this.baseVideoHeight / this.baseVideoWidth)
 178   }
 179
 180   private minPageLoaded () {
 181     return Math.min(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 182   }
 183
 184   private maxPageLoaded () {
 185     return Math.max(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 186   }
 187
 188   private calcPageSizes () {
 189     if (isInMobileView() || this.baseVideoWidth === -1) {
 190       this.pagination.itemsPerPage = 5
 191
 192       // Video takes all the width
 193       this.videoWidth = -1
 194       this.videoHeight = this.buildVideoHeight()
 195       this.pageHeight = this.pagination.itemsPerPage * this.videoHeight
 196     } else {
 197       this.videoWidth = this.baseVideoWidth
 198       this.videoHeight = this.baseVideoHeight
 199
 200       const videosWidth = this.videosElement.nativeElement.offsetWidth
 201       this.pagination.itemsPerPage = Math.floor(videosWidth / this.videoWidth) * AbstractVideoList.LINES_PER_PAGE
 202       this.pageHeight = this.videoHeight * AbstractVideoList.LINES_PER_PAGE
 203     }
 204
 205     // Rebuild pages because maybe we modified the number of items per page
 206     const videos = [].concat(...this.videoPages)
 207     this.loadedPages = {}
 208
 209     let i = 1
 210     // Don't include the last page if it not complete
 211     while (videos.length >= this.pagination.itemsPerPage && i < 10000) { // 10000 -> Hard limit in case of infinite loop
 212       this.loadedPages[i] = videos.splice(0, this.pagination.itemsPerPage)
 213       i++
 214     }
 215
 216     // Re fetch the last page
 217     if (videos.length !== 0) {
 218       this.loadMoreVideos(i)
 219     } else {
 220       this.buildVideoPages()
 221     }
 222
 223     console.log('Rebuilt pages with %s elements per page.', this.pagination.itemsPerPage)
 224   }
 225 }