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 { NotificationsService } from 'angular2-notifications'
   7 import { fromEvent, Observable, Subscription } from 'rxjs'
   8 import { AuthService } from '../../core/auth'
   9 import { ComponentPagination } from '../rest/component-pagination.model'
  10 import { VideoSortField } from './sort-field.type'
  11 import { Video } from './video.model'
  12 import { I18n } from '@ngx-translate/i18n-polyfill'
  13 import { ScreenService } from '@app/shared/misc/screen.service'
  14 import { OwnerDisplayType } from '@app/shared/video/video-miniature.component'
  15
  16 export abstract class AbstractVideoList implements OnInit, OnDestroy {
  17   private static LINES_PER_PAGE = 4
  18
  19   @ViewChild('videosElement') videosElement: ElementRef
  20   @ViewChild(InfiniteScrollerDirective) infiniteScroller: InfiniteScrollerDirective
  21
  22   pagination: ComponentPagination = {
  23     currentPage: 1,
  24     itemsPerPage: 10,
  25     totalItems: null
  26   }
  27   sort: VideoSortField = '-publishedAt'
  28   categoryOneOf?: number
  29   defaultSort: VideoSortField = '-publishedAt'
  30   syndicationItems = []
  31
  32   loadOnInit = true
  33   marginContent = true
  34   pageHeight: number
  35   videoWidth: number
  36   videoHeight: number
  37   videoPages: Video[][] = []
  38   ownerDisplayType: OwnerDisplayType = 'account'
  39   firstLoadedPage: number
  40
  41   protected baseVideoWidth = 215
  42   protected baseVideoHeight = 205
  43
  44   protected abstract notificationsService: NotificationsService
  45   protected abstract authService: AuthService
  46   protected abstract router: Router
  47   protected abstract route: ActivatedRoute
  48   protected abstract screenService: ScreenService
  49   protected abstract i18n: I18n
  50   protected abstract location: Location
  51   protected abstract currentRoute: string
  52   abstract titlePage: string
  53
  54   protected loadedPages: { [ id: number ]: Video[] } = {}
  55   protected loadingPage: { [ id: number ]: boolean } = {}
  56   protected otherRouteParams = {}
  57
  58   private resizeSubscription: Subscription
  59
  60   abstract getVideosObservable (page: number): Observable<{ videos: Video[], totalVideos: number}>
  61   abstract generateSyndicationList ()
  62
  63   get user () {
  64     return this.authService.getUser()
  65   }
  66
  67   ngOnInit () {
  68     // Subscribe to route changes
  69     const routeParams = this.route.snapshot.queryParams
  70     this.loadRouteParams(routeParams)
  71
  72     this.resizeSubscription = fromEvent(window, 'resize')
  73       .pipe(debounceTime(500))
  74       .subscribe(() => this.calcPageSizes())
  75
  76     this.calcPageSizes()
  77     if (this.loadOnInit === true) this.loadMoreVideos(this.pagination.currentPage)
  78   }
  79
  80   ngOnDestroy () {
  81     if (this.resizeSubscription) this.resizeSubscription.unsubscribe()
  82   }
  83
  84   pageByVideoId (index: number, page: Video[]) {
  85     // Video are unique in all pages
  86     return page[0].id
  87   }
  88
  89   videoById (index: number, video: Video) {
  90     return video.id
  91   }
  92
  93   onNearOfTop () {
  94     this.previousPage()
  95   }
  96
  97   onNearOfBottom () {
  98     if (this.hasMoreVideos()) {
  99       this.nextPage()
 100     }
 101   }
 102
 103   onPageChanged (page: number) {
 104     this.pagination.currentPage = page
 105     this.setNewRouteParams()
 106   }
 107
 108   reloadVideos () {
 109     this.loadedPages = {}
 110     this.loadMoreVideos(this.pagination.currentPage)
 111   }
 112
 113   loadMoreVideos (page: number, loadOnTop = false) {
 114     this.adjustVideoPageHeight()
 115
 116     const currentY = window.scrollY
 117
 118     if (this.loadedPages[page] !== undefined) return
 119     if (this.loadingPage[page] === true) return
 120
 121     this.loadingPage[page] = true
 122     const observable = this.getVideosObservable(page)
 123
 124     observable.subscribe(
 125       ({ videos, totalVideos }) => {
 126         this.loadingPage[page] = false
 127
 128         if (this.firstLoadedPage === undefined || this.firstLoadedPage > page) this.firstLoadedPage = page
 129
 130         // Paging is too high, return to the first one
 131         if (this.pagination.currentPage > 1 && totalVideos <= ((this.pagination.currentPage - 1) * this.pagination.itemsPerPage)) {
 132           this.pagination.currentPage = 1
 133           this.setNewRouteParams()
 134           return this.reloadVideos()
 135         }
 136
 137         this.loadedPages[page] = videos
 138         this.buildVideoPages()
 139         this.pagination.totalItems = totalVideos
 140
 141         // Initialize infinite scroller now we loaded the first page
 142         if (Object.keys(this.loadedPages).length === 1) {
 143           // Wait elements creation
 144           setTimeout(() => {
 145             this.infiniteScroller.initialize()
 146
 147             // At our first load, we did not load the first page
 148             // Load the previous page so the user can move on the top (and browser previous pages)
 149             if (this.pagination.currentPage > 1) this.loadMoreVideos(this.pagination.currentPage - 1, true)
 150           }, 500)
 151         }
 152
 153         // Insert elements on the top but keep the scroll in the previous position
 154         if (loadOnTop) setTimeout(() => { window.scrollTo(0, currentY + this.pageHeight) }, 0)
 155       },
 156       error => {
 157         this.loadingPage[page] = false
 158         this.notificationsService.error(this.i18n('Error'), error.message)
 159       }
 160     )
 161   }
 162
 163   protected hasMoreVideos () {
 164     // No results
 165     if (this.pagination.totalItems === 0) return false
 166
 167     // Not loaded yet
 168     if (!this.pagination.totalItems) return true
 169
 170     const maxPage = this.pagination.totalItems / this.pagination.itemsPerPage
 171     return maxPage > this.maxPageLoaded()
 172   }
 173
 174   protected previousPage () {
 175     const min = this.minPageLoaded()
 176
 177     if (min > 1) {
 178       this.loadMoreVideos(min - 1, true)
 179     }
 180   }
 181
 182   protected nextPage () {
 183     this.loadMoreVideos(this.maxPageLoaded() + 1)
 184   }
 185
 186   protected buildRouteParams () {
 187     // There is always a sort and a current page
 188     const params = {
 189       sort: this.sort,
 190       page: this.pagination.currentPage
 191     }
 192
 193     return Object.assign(params, this.otherRouteParams)
 194   }
 195
 196   protected loadRouteParams (routeParams: { [ key: string ]: any }) {
 197     this.sort = routeParams['sort'] as VideoSortField || this.defaultSort
 198     this.categoryOneOf = routeParams['categoryOneOf']
 199     if (routeParams['page'] !== undefined) {
 200       this.pagination.currentPage = parseInt(routeParams['page'], 10)
 201     } else {
 202       this.pagination.currentPage = 1
 203     }
 204   }
 205
 206   protected setNewRouteParams () {
 207     const paramsObject = this.buildRouteParams()
 208
 209     const queryParams = Object.keys(paramsObject).map(p => p + '=' + paramsObject[p]).join('&')
 210     this.location.replaceState(this.currentRoute, queryParams)
 211   }
 212
 213   protected buildVideoPages () {
 214     this.videoPages = Object.values(this.loadedPages)
 215   }
 216
 217   protected adjustVideoPageHeight () {
 218     const numberOfPagesLoaded = Object.keys(this.loadedPages).length
 219     if (!numberOfPagesLoaded) return
 220
 221     this.pageHeight = this.videosElement.nativeElement.offsetHeight / numberOfPagesLoaded
 222   }
 223
 224   protected buildVideoHeight () {
 225     // Same ratios than base width/height
 226     return this.videosElement.nativeElement.offsetWidth * (this.baseVideoHeight / this.baseVideoWidth)
 227   }
 228
 229   private minPageLoaded () {
 230     return Math.min(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 231   }
 232
 233   private maxPageLoaded () {
 234     return Math.max(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 235   }
 236
 237   private calcPageSizes () {
 238     if (this.screenService.isInMobileView() || this.baseVideoWidth === -1) {
 239       this.pagination.itemsPerPage = 5
 240
 241       // Video takes all the width
 242       this.videoWidth = -1
 243       this.videoHeight = this.buildVideoHeight()
 244       this.pageHeight = this.pagination.itemsPerPage * this.videoHeight
 245     } else {
 246       this.videoWidth = this.baseVideoWidth
 247       this.videoHeight = this.baseVideoHeight
 248
 249       const videosWidth = this.videosElement.nativeElement.offsetWidth
 250       this.pagination.itemsPerPage = Math.floor(videosWidth / this.videoWidth) * AbstractVideoList.LINES_PER_PAGE
 251       this.pageHeight = this.videoHeight * AbstractVideoList.LINES_PER_PAGE
 252     }
 253
 254     // Rebuild pages because maybe we modified the number of items per page
 255     const videos = [].concat(...this.videoPages)
 256     this.loadedPages = {}
 257
 258     let i = 1
 259     // Don't include the last page if it not complete
 260     while (videos.length >= this.pagination.itemsPerPage && i < 10000) { // 10000 -> Hard limit in case of infinite loop
 261       this.loadedPages[i] = videos.splice(0, this.pagination.itemsPerPage)
 262       i++
 263     }
 264
 265     // Re fetch the last page
 266     if (videos.length !== 0) {
 267       this.loadMoreVideos(i)
 268     } else {
 269       this.buildVideoPages()
 270     }
 271
 272     console.log('Rebuilt pages with %s elements per page.', this.pagination.itemsPerPage)
 273   }
 274 }