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 { InfiniteScrollerDirective } from '@app/shared/video/infinite-scroller.directive'
   6 import { fromEvent, Observable, Subscription } from 'rxjs'
   7 import { AuthService } from '../../core/auth'
   8 import { ComponentPagination } from '../rest/component-pagination.model'
   9 import { VideoSortField } from './sort-field.type'
  10 import { Video } from './video.model'
  11 import { I18n } from '@ngx-translate/i18n-polyfill'
  12 import { ScreenService } from '@app/shared/misc/screen.service'
  13 import { OwnerDisplayType } from '@app/shared/video/video-miniature.component'
  14 import { Syndication } from '@app/shared/video/syndication.model'
  15 import { Notifier } from '@app/core'
  16
  17 export abstract class AbstractVideoList implements OnInit, OnDestroy {
  18   private static LINES_PER_PAGE = 4
  19
  20   @ViewChild('videosElement') videosElement: ElementRef
  21   @ViewChild(InfiniteScrollerDirective) infiniteScroller: InfiniteScrollerDirective
  22
  23   pagination: ComponentPagination = {
  24     currentPage: 1,
  25     itemsPerPage: 10,
  26     totalItems: null
  27   }
  28   sort: VideoSortField = '-publishedAt'
  29   categoryOneOf?: number
  30   defaultSort: VideoSortField = '-publishedAt'
  31   syndicationItems: Syndication[] = []
  32
  33   loadOnInit = true
  34   marginContent = true
  35   pageHeight: number
  36   videoWidth: number
  37   videoHeight: number
  38   videoPages: Video[][] = []
  39   ownerDisplayType: OwnerDisplayType = 'account'
  40   firstLoadedPage: number
  41   displayModerationBlock = false
  42   titleTooltip: string
  43
  44   protected baseVideoWidth = 238
  45   protected baseVideoHeight = 225
  46
  47   protected abstract notifier: Notifier
  48   protected abstract authService: AuthService
  49   protected abstract router: Router
  50   protected abstract route: ActivatedRoute
  51   protected abstract screenService: ScreenService
  52   protected abstract i18n: I18n
  53   protected abstract location: Location
  54   protected abstract currentRoute: string
  55   abstract titlePage: string
  56
  57   protected loadedPages: { [ id: number ]: Video[] } = {}
  58   protected loadingPage: { [ id: number ]: boolean } = {}
  59   protected otherRouteParams = {}
  60
  61   private resizeSubscription: Subscription
  62
  63   abstract getVideosObservable (page: number): Observable<{ videos: Video[], totalVideos: number}>
  64   abstract generateSyndicationList (): void
  65
  66   get user () {
  67     return this.authService.getUser()
  68   }
  69
  70   ngOnInit () {
  71     // Subscribe to route changes
  72     const routeParams = this.route.snapshot.queryParams
  73     this.loadRouteParams(routeParams)
  74
  75     this.resizeSubscription = fromEvent(window, 'resize')
  76       .pipe(debounceTime(500))
  77       .subscribe(() => this.calcPageSizes())
  78
  79     this.calcPageSizes()
  80     if (this.loadOnInit === true) this.loadMoreVideos(this.pagination.currentPage)
  81   }
  82
  83   ngOnDestroy () {
  84     if (this.resizeSubscription) this.resizeSubscription.unsubscribe()
  85   }
  86
  87   pageByVideoId (index: number, page: Video[]) {
  88     // Video are unique in all pages
  89     return page.length !== 0 ? page[0].id : 0
  90   }
  91
  92   videoById (index: number, video: Video) {
  93     return video.id
  94   }
  95
  96   onNearOfTop () {
  97     this.previousPage()
  98   }
  99
 100   onNearOfBottom () {
 101     if (this.hasMoreVideos()) {
 102       this.nextPage()
 103     }
 104   }
 105
 106   onPageChanged (page: number) {
 107     this.pagination.currentPage = page
 108     this.setNewRouteParams()
 109   }
 110
 111   reloadVideos () {
 112     this.loadedPages = {}
 113     this.loadMoreVideos(this.pagination.currentPage)
 114   }
 115
 116   loadMoreVideos (page: number, loadOnTop = false) {
 117     this.adjustVideoPageHeight()
 118
 119     const currentY = window.scrollY
 120
 121     if (this.loadedPages[page] !== undefined) return
 122     if (this.loadingPage[page] === true) return
 123
 124     this.loadingPage[page] = true
 125     const observable = this.getVideosObservable(page)
 126
 127     observable.subscribe(
 128       ({ videos, totalVideos }) => {
 129         this.loadingPage[page] = false
 130
 131         if (this.firstLoadedPage === undefined || this.firstLoadedPage > page) this.firstLoadedPage = page
 132
 133         // Paging is too high, return to the first one
 134         if (this.pagination.currentPage > 1 && totalVideos <= ((this.pagination.currentPage - 1) * this.pagination.itemsPerPage)) {
 135           this.pagination.currentPage = 1
 136           this.setNewRouteParams()
 137           return this.reloadVideos()
 138         }
 139
 140         this.loadedPages[page] = videos
 141         this.buildVideoPages()
 142         this.pagination.totalItems = totalVideos
 143
 144         // Initialize infinite scroller now we loaded the first page
 145         if (Object.keys(this.loadedPages).length === 1) {
 146           // Wait elements creation
 147           setTimeout(() => {
 148             this.infiniteScroller.initialize()
 149
 150             // At our first load, we did not load the first page
 151             // Load the previous page so the user can move on the top (and browser previous pages)
 152             if (this.pagination.currentPage > 1) this.loadMoreVideos(this.pagination.currentPage - 1, true)
 153           }, 500)
 154         }
 155
 156         // Insert elements on the top but keep the scroll in the previous position
 157         if (loadOnTop) setTimeout(() => { window.scrollTo(0, currentY + this.pageHeight) }, 0)
 158       },
 159       error => {
 160         this.loadingPage[page] = false
 161         this.notifier.error(error.message)
 162       }
 163     )
 164   }
 165
 166   toggleModerationDisplay () {
 167     throw new Error('toggleModerationDisplay is not implemented')
 168   }
 169
 170   protected hasMoreVideos () {
 171     // No results
 172     if (this.pagination.totalItems === 0) return false
 173
 174     // Not loaded yet
 175     if (!this.pagination.totalItems) return true
 176
 177     const maxPage = this.pagination.totalItems / this.pagination.itemsPerPage
 178     return maxPage > this.maxPageLoaded()
 179   }
 180
 181   protected previousPage () {
 182     const min = this.minPageLoaded()
 183
 184     if (min > 1) {
 185       this.loadMoreVideos(min - 1, true)
 186     }
 187   }
 188
 189   protected nextPage () {
 190     this.loadMoreVideos(this.maxPageLoaded() + 1)
 191   }
 192
 193   protected buildRouteParams () {
 194     // There is always a sort and a current page
 195     const params = {
 196       sort: this.sort,
 197       page: this.pagination.currentPage
 198     }
 199
 200     return Object.assign(params, this.otherRouteParams)
 201   }
 202
 203   protected loadRouteParams (routeParams: { [ key: string ]: any }) {
 204     this.sort = routeParams['sort'] as VideoSortField || this.defaultSort
 205     this.categoryOneOf = routeParams['categoryOneOf']
 206     if (routeParams['page'] !== undefined) {
 207       this.pagination.currentPage = parseInt(routeParams['page'], 10)
 208     } else {
 209       this.pagination.currentPage = 1
 210     }
 211   }
 212
 213   protected setNewRouteParams () {
 214     const paramsObject = this.buildRouteParams()
 215
 216     const queryParams = Object.keys(paramsObject)
 217                               .map(p => p + '=' + paramsObject[p])
 218                               .join('&')
 219     this.location.replaceState(this.currentRoute, queryParams)
 220   }
 221
 222   protected buildVideoPages () {
 223     this.videoPages = Object.values(this.loadedPages)
 224   }
 225
 226   protected adjustVideoPageHeight () {
 227     const numberOfPagesLoaded = Object.keys(this.loadedPages).length
 228     if (!numberOfPagesLoaded) return
 229
 230     this.pageHeight = this.videosElement.nativeElement.offsetHeight / numberOfPagesLoaded
 231   }
 232
 233   protected buildVideoHeight () {
 234     // Same ratios than base width/height
 235     return this.videosElement.nativeElement.offsetWidth * (this.baseVideoHeight / this.baseVideoWidth)
 236   }
 237
 238   private minPageLoaded () {
 239     return Math.min(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 240   }
 241
 242   private maxPageLoaded () {
 243     return Math.max(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 244   }
 245
 246   private calcPageSizes () {
 247     if (this.screenService.isInMobileView() || this.baseVideoWidth === -1) {
 248       this.pagination.itemsPerPage = 5
 249
 250       // Video takes all the width
 251       this.videoWidth = -1
 252       this.videoHeight = this.buildVideoHeight()
 253       this.pageHeight = this.pagination.itemsPerPage * this.videoHeight
 254     } else {
 255       this.videoWidth = this.baseVideoWidth
 256       this.videoHeight = this.baseVideoHeight
 257
 258       const videosWidth = this.videosElement.nativeElement.offsetWidth
 259       this.pagination.itemsPerPage = Math.floor(videosWidth / this.videoWidth) * AbstractVideoList.LINES_PER_PAGE
 260       this.pageHeight = this.videoHeight * AbstractVideoList.LINES_PER_PAGE
 261     }
 262
 263     // Rebuild pages because maybe we modified the number of items per page
 264     const videos = [].concat(...this.videoPages)
 265     this.loadedPages = {}
 266
 267     let i = 1
 268     // Don't include the last page if it not complete
 269     while (videos.length >= this.pagination.itemsPerPage && i < 10000) { // 10000 -> Hard limit in case of infinite loop
 270       this.loadedPages[i] = videos.splice(0, this.pagination.itemsPerPage)
 271       i++
 272     }
 273
 274     // Re fetch the last page
 275     if (videos.length !== 0) {
 276       this.loadMoreVideos(i)
 277     } else {
 278       this.buildVideoPages()
 279     }
 280
 281     console.log('Rebuilt pages with %s elements per page.', this.pagination.itemsPerPage)
 282   }
 283 }