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