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

   1 import { debounceTime } from 'rxjs/operators'
   2 import { ElementRef, OnDestroy, OnInit, ViewChild } from '@angular/core'
   3 import { ActivatedRoute, Router } from '@angular/router'
   4 import { Location } from '@angular/common'
   5 import { isInMobileView } from '@app/shared/misc/utils'
   6 import { InfiniteScrollerDirective } from '@app/shared/video/infinite-scroller.directive'
   7 import { NotificationsService } from 'angular2-notifications'
   8 import { fromEvent, Observable, Subscription } from 'rxjs'
   9 import { AuthService } from '../../core/auth'
  10 import { ComponentPagination } from '../rest/component-pagination.model'
  11 import { VideoSortField } from './sort-field.type'
  12 import { Video } from './video.model'
  13 import { I18n } from '@ngx-translate/i18n-polyfill'
  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: VideoSortField = '-publishedAt'
  27   defaultSort: VideoSortField = '-publishedAt'
  28   syndicationItems = []
  29
  30   loadOnInit = true
  31   marginContent = true
  32   pageHeight: number
  33   videoWidth: number
  34   videoHeight: number
  35   videoPages: Video[][] = []
  36
  37   protected baseVideoWidth = 215
  38   protected baseVideoHeight = 230
  39
  40   protected abstract notificationsService: NotificationsService
  41   protected abstract authService: AuthService
  42   protected abstract router: Router
  43   protected abstract route: ActivatedRoute
  44   protected abstract i18n: I18n
  45   protected abstract location: Location
  46   protected abstract currentRoute: string
  47   abstract titlePage: string
  48
  49   protected loadedPages: { [ id: number ]: Video[] } = {}
  50   protected loadingPage: { [ id: number ]: boolean } = {}
  51   protected otherRouteParams = {}
  52
  53   private resizeSubscription: Subscription
  54
  55   abstract getVideosObservable (page: number): Observable<{ videos: Video[], totalVideos: number}>
  56   abstract generateSyndicationList ()
  57
  58   get user () {
  59     return this.authService.getUser()
  60   }
  61
  62   ngOnInit () {
  63     // Subscribe to route changes
  64     const routeParams = this.route.snapshot.queryParams
  65     this.loadRouteParams(routeParams)
  66
  67     this.resizeSubscription = fromEvent(window, 'resize')
  68       .pipe(debounceTime(500))
  69       .subscribe(() => this.calcPageSizes())
  70
  71     this.calcPageSizes()
  72     if (this.loadOnInit === true) this.loadMoreVideos(this.pagination.currentPage)
  73   }
  74
  75   ngOnDestroy () {
  76     if (this.resizeSubscription) this.resizeSubscription.unsubscribe()
  77   }
  78
  79   onNearOfTop () {
  80     this.previousPage()
  81   }
  82
  83   onNearOfBottom () {
  84     if (this.hasMoreVideos()) {
  85       this.nextPage()
  86     }
  87   }
  88
  89   onPageChanged (page: number) {
  90     this.pagination.currentPage = page
  91     this.setNewRouteParams()
  92   }
  93
  94   reloadVideos () {
  95     this.loadedPages = {}
  96     this.loadMoreVideos(this.pagination.currentPage)
  97   }
  98
  99   loadMoreVideos (page: number) {
 100     if (this.loadedPages[page] !== undefined) return
 101     if (this.loadingPage[page] === true) return
 102
 103     this.loadingPage[page] = true
 104     const observable = this.getVideosObservable(page)
 105
 106     observable.subscribe(
 107       ({ videos, totalVideos }) => {
 108         this.loadingPage[page] = false
 109
 110         // Paging is too high, return to the first one
 111         if (this.pagination.currentPage > 1 && totalVideos <= ((this.pagination.currentPage - 1) * this.pagination.itemsPerPage)) {
 112           this.pagination.currentPage = 1
 113           this.setNewRouteParams()
 114           return this.reloadVideos()
 115         }
 116
 117         this.loadedPages[page] = videos
 118         this.buildVideoPages()
 119         this.pagination.totalItems = totalVideos
 120
 121         // Initialize infinite scroller now we loaded the first page
 122         if (Object.keys(this.loadedPages).length === 1) {
 123           // Wait elements creation
 124           setTimeout(() => this.infiniteScroller.initialize(), 500)
 125         }
 126       },
 127       error => {
 128         this.loadingPage[page] = false
 129         this.notificationsService.error(this.i18n('Error'), error.message)
 130       }
 131     )
 132   }
 133
 134   protected hasMoreVideos () {
 135     // No results
 136     if (this.pagination.totalItems === 0) return false
 137
 138     // Not loaded yet
 139     if (!this.pagination.totalItems) return true
 140
 141     const maxPage = this.pagination.totalItems / this.pagination.itemsPerPage
 142     return maxPage > this.maxPageLoaded()
 143   }
 144
 145   protected previousPage () {
 146     const min = this.minPageLoaded()
 147
 148     if (min > 1) {
 149       this.loadMoreVideos(min - 1)
 150     }
 151   }
 152
 153   protected nextPage () {
 154     this.loadMoreVideos(this.maxPageLoaded() + 1)
 155   }
 156
 157   protected buildRouteParams () {
 158     // There is always a sort and a current page
 159     const params = {
 160       sort: this.sort,
 161       page: this.pagination.currentPage
 162     }
 163
 164     return Object.assign(params, this.otherRouteParams)
 165   }
 166
 167   protected loadRouteParams (routeParams: { [ key: string ]: any }) {
 168     this.sort = routeParams['sort'] as VideoSortField || this.defaultSort
 169
 170     if (routeParams['page'] !== undefined) {
 171       this.pagination.currentPage = parseInt(routeParams['page'], 10)
 172     } else {
 173       this.pagination.currentPage = 1
 174     }
 175   }
 176
 177   protected setNewRouteParams () {
 178     const paramsObject = this.buildRouteParams()
 179
 180     const queryParams = Object.keys(paramsObject).map(p => p + '=' + paramsObject[p]).join('&')
 181     this.location.replaceState(this.currentRoute, queryParams)
 182   }
 183
 184   protected buildVideoPages () {
 185     this.videoPages = Object.values(this.loadedPages)
 186   }
 187
 188   protected buildVideoHeight () {
 189     // Same ratios than base width/height
 190     return this.videosElement.nativeElement.offsetWidth * (this.baseVideoHeight / this.baseVideoWidth)
 191   }
 192
 193   private minPageLoaded () {
 194     return Math.min(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 195   }
 196
 197   private maxPageLoaded () {
 198     return Math.max(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 199   }
 200
 201   private calcPageSizes () {
 202     if (isInMobileView() || this.baseVideoWidth === -1) {
 203       this.pagination.itemsPerPage = 5
 204
 205       // Video takes all the width
 206       this.videoWidth = -1
 207       this.videoHeight = this.buildVideoHeight()
 208       this.pageHeight = this.pagination.itemsPerPage * this.videoHeight
 209     } else {
 210       this.videoWidth = this.baseVideoWidth
 211       this.videoHeight = this.baseVideoHeight
 212
 213       const videosWidth = this.videosElement.nativeElement.offsetWidth
 214       this.pagination.itemsPerPage = Math.floor(videosWidth / this.videoWidth) * AbstractVideoList.LINES_PER_PAGE
 215       this.pageHeight = this.videoHeight * AbstractVideoList.LINES_PER_PAGE
 216     }
 217
 218     // Rebuild pages because maybe we modified the number of items per page
 219     const videos = [].concat(...this.videoPages)
 220     this.loadedPages = {}
 221
 222     let i = 1
 223     // Don't include the last page if it not complete
 224     while (videos.length >= this.pagination.itemsPerPage && i < 10000) { // 10000 -> Hard limit in case of infinite loop
 225       this.loadedPages[i] = videos.splice(0, this.pagination.itemsPerPage)
 226       i++
 227     }
 228
 229     // Re fetch the last page
 230     if (videos.length !== 0) {
 231       this.loadMoreVideos(i)
 232     } else {
 233       this.buildVideoPages()
 234     }
 235
 236     console.log('Rebuilt pages with %s elements per page.', this.pagination.itemsPerPage)
 237   }
 238 }