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   trendingDays: number
  43   titleTooltip: string
  44
  45   protected baseVideoWidth = 215
  46   protected baseVideoHeight = 205
  47
  48   protected abstract notifier: Notifier
  49   protected abstract authService: AuthService
  50   protected abstract router: Router
  51   protected abstract route: ActivatedRoute
  52   protected abstract screenService: ScreenService
  53   protected abstract i18n: I18n
  54   protected abstract location: Location
  55   protected abstract currentRoute: string
  56   abstract titlePage: string
  57
  58   protected loadedPages: { [ id: number ]: Video[] } = {}
  59   protected loadingPage: { [ id: number ]: boolean } = {}
  60   protected otherRouteParams = {}
  61
  62   private resizeSubscription: Subscription
  63
  64   abstract getVideosObservable (page: number): Observable<{ videos: Video[], totalVideos: number}>
  65   abstract generateSyndicationList (): void
  66
  67   get user () {
  68     return this.authService.getUser()
  69   }
  70
  71   ngOnInit () {
  72     // Subscribe to route changes
  73     const routeParams = this.route.snapshot.queryParams
  74     this.loadRouteParams(routeParams)
  75
  76     this.resizeSubscription = fromEvent(window, 'resize')
  77       .pipe(debounceTime(500))
  78       .subscribe(() => this.calcPageSizes())
  79
  80     this.calcPageSizes()
  81     if (this.loadOnInit === true) this.loadMoreVideos(this.pagination.currentPage)
  82   }
  83
  84   ngOnDestroy () {
  85     if (this.resizeSubscription) this.resizeSubscription.unsubscribe()
  86   }
  87
  88   pageByVideoId (index: number, page: Video[]) {
  89     // Video are unique in all pages
  90     return page.length !== 0 ? page[0].id : 0
  91   }
  92
  93   videoById (index: number, video: Video) {
  94     return video.id
  95   }
  96
  97   onNearOfTop () {
  98     this.previousPage()
  99   }
 100
 101   onNearOfBottom () {
 102     if (this.hasMoreVideos()) {
 103       this.nextPage()
 104     }
 105   }
 106
 107   onPageChanged (page: number) {
 108     this.pagination.currentPage = page
 109     this.setNewRouteParams()
 110   }
 111
 112   reloadVideos () {
 113     this.loadedPages = {}
 114     this.loadMoreVideos(this.pagination.currentPage)
 115   }
 116
 117   loadMoreVideos (page: number, loadOnTop = false) {
 118     this.adjustVideoPageHeight()
 119
 120     const currentY = window.scrollY
 121
 122     if (this.loadedPages[page] !== undefined) return
 123     if (this.loadingPage[page] === true) return
 124
 125     this.loadingPage[page] = true
 126     const observable = this.getVideosObservable(page)
 127
 128     observable.subscribe(
 129       ({ videos, totalVideos }) => {
 130         this.loadingPage[page] = false
 131
 132         if (this.firstLoadedPage === undefined || this.firstLoadedPage > page) this.firstLoadedPage = page
 133
 134         // Paging is too high, return to the first one
 135         if (this.pagination.currentPage > 1 && totalVideos <= ((this.pagination.currentPage - 1) * this.pagination.itemsPerPage)) {
 136           this.pagination.currentPage = 1
 137           this.setNewRouteParams()
 138           return this.reloadVideos()
 139         }
 140
 141         this.loadedPages[page] = videos
 142         this.buildVideoPages()
 143         this.pagination.totalItems = totalVideos
 144
 145         // Initialize infinite scroller now we loaded the first page
 146         if (Object.keys(this.loadedPages).length === 1) {
 147           // Wait elements creation
 148           setTimeout(() => {
 149             this.infiniteScroller.initialize()
 150
 151             // At our first load, we did not load the first page
 152             // Load the previous page so the user can move on the top (and browser previous pages)
 153             if (this.pagination.currentPage > 1) this.loadMoreVideos(this.pagination.currentPage - 1, true)
 154           }, 500)
 155         }
 156
 157         // Insert elements on the top but keep the scroll in the previous position
 158         if (loadOnTop) setTimeout(() => { window.scrollTo(0, currentY + this.pageHeight) }, 0)
 159       },
 160       error => {
 161         this.loadingPage[page] = false
 162         this.notifier.error(error.message)
 163       }
 164     )
 165   }
 166
 167   toggleModerationDisplay () {
 168     throw new Error('toggleModerationDisplay is not implemented')
 169   }
 170
 171   protected hasMoreVideos () {
 172     // No results
 173     if (this.pagination.totalItems === 0) return false
 174
 175     // Not loaded yet
 176     if (!this.pagination.totalItems) return true
 177
 178     const maxPage = this.pagination.totalItems / this.pagination.itemsPerPage
 179     return maxPage > this.maxPageLoaded()
 180   }
 181
 182   protected previousPage () {
 183     const min = this.minPageLoaded()
 184
 185     if (min > 1) {
 186       this.loadMoreVideos(min - 1, true)
 187     }
 188   }
 189
 190   protected nextPage () {
 191     this.loadMoreVideos(this.maxPageLoaded() + 1)
 192   }
 193
 194   protected buildRouteParams () {
 195     // There is always a sort and a current page
 196     const params = {
 197       sort: this.sort,
 198       page: this.pagination.currentPage
 199     }
 200
 201     return Object.assign(params, this.otherRouteParams)
 202   }
 203
 204   protected loadRouteParams (routeParams: { [ key: string ]: any }) {
 205     this.sort = routeParams['sort'] as VideoSortField || this.defaultSort
 206     this.categoryOneOf = routeParams['categoryOneOf']
 207     if (routeParams['page'] !== undefined) {
 208       this.pagination.currentPage = parseInt(routeParams['page'], 10)
 209     } else {
 210       this.pagination.currentPage = 1
 211     }
 212   }
 213
 214   protected setNewRouteParams () {
 215     const paramsObject = this.buildRouteParams()
 216
 217     const queryParams = Object.keys(paramsObject)
 218                               .map(p => p + '=' + paramsObject[p])
 219                               .join('&')
 220     this.location.replaceState(this.currentRoute, queryParams)
 221   }
 222
 223   protected buildVideoPages () {
 224     this.videoPages = Object.values(this.loadedPages)
 225   }
 226
 227   protected adjustVideoPageHeight () {
 228     const numberOfPagesLoaded = Object.keys(this.loadedPages).length
 229     if (!numberOfPagesLoaded) return
 230
 231     this.pageHeight = this.videosElement.nativeElement.offsetHeight / numberOfPagesLoaded
 232   }
 233
 234   protected buildVideoHeight () {
 235     // Same ratios than base width/height
 236     return this.videosElement.nativeElement.offsetWidth * (this.baseVideoHeight / this.baseVideoWidth)
 237   }
 238
 239   private minPageLoaded () {
 240     return Math.min(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 241   }
 242
 243   private maxPageLoaded () {
 244     return Math.max(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 245   }
 246
 247   private calcPageSizes () {
 248     if (this.screenService.isInMobileView() || this.baseVideoWidth === -1) {
 249       this.pagination.itemsPerPage = 5
 250
 251       // Video takes all the width
 252       this.videoWidth = -1
 253       this.videoHeight = this.buildVideoHeight()
 254       this.pageHeight = this.pagination.itemsPerPage * this.videoHeight
 255     } else {
 256       this.videoWidth = this.baseVideoWidth
 257       this.videoHeight = this.baseVideoHeight
 258
 259       const videosWidth = this.videosElement.nativeElement.offsetWidth
 260       this.pagination.itemsPerPage = Math.floor(videosWidth / this.videoWidth) * AbstractVideoList.LINES_PER_PAGE
 261       this.pageHeight = this.videoHeight * AbstractVideoList.LINES_PER_PAGE
 262     }
 263
 264     // Rebuild pages because maybe we modified the number of items per page
 265     const videos = [].concat(...this.videoPages)
 266     this.loadedPages = {}
 267
 268     let i = 1
 269     // Don't include the last page if it not complete
 270     while (videos.length >= this.pagination.itemsPerPage && i < 10000) { // 10000 -> Hard limit in case of infinite loop
 271       this.loadedPages[i] = videos.splice(0, this.pagination.itemsPerPage)
 272       i++
 273     }
 274
 275     // Re fetch the last page
 276     if (videos.length !== 0) {
 277       this.loadMoreVideos(i)
 278     } else {
 279       this.buildVideoPages()
 280     }
 281
 282     console.log('Rebuilt pages with %s elements per page.', this.pagination.itemsPerPage)
 283   }
 284 }