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
  40   protected baseVideoWidth = 215
  41   protected baseVideoHeight = 205
  42
  43   protected abstract notificationsService: NotificationsService
  44   protected abstract authService: AuthService
  45   protected abstract router: Router
  46   protected abstract route: ActivatedRoute
  47   protected abstract screenService: ScreenService
  48   protected abstract i18n: I18n
  49   protected abstract location: Location
  50   protected abstract currentRoute: string
  51   abstract titlePage: string
  52
  53   protected loadedPages: { [ id: number ]: Video[] } = {}
  54   protected loadingPage: { [ id: number ]: boolean } = {}
  55   protected otherRouteParams = {}
  56
  57   private resizeSubscription: Subscription
  58   private firstLoadedPage: number
  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   onNearOfTop () {
  85     this.previousPage()
  86   }
  87
  88   onNearOfBottom () {
  89     if (this.hasMoreVideos()) {
  90       this.nextPage()
  91     }
  92   }
  93
  94   onPageChanged (page: number) {
  95     this.pagination.currentPage = page
  96     this.setNewRouteParams()
  97   }
  98
  99   reloadVideos () {
 100     this.loadedPages = {}
 101     this.loadMoreVideos(this.pagination.currentPage)
 102   }
 103
 104   loadMoreVideos (page: number, loadOnTop = false) {
 105     this.adjustVideoPageHeight()
 106
 107     const currentY = window.scrollY
 108
 109     if (this.loadedPages[page] !== undefined) return
 110     if (this.loadingPage[page] === true) return
 111
 112     this.loadingPage[page] = true
 113     const observable = this.getVideosObservable(page)
 114
 115     observable.subscribe(
 116       ({ videos, totalVideos }) => {
 117         this.loadingPage[page] = false
 118
 119         if (this.firstLoadedPage === undefined || this.firstLoadedPage > page) this.firstLoadedPage = page
 120
 121         // Paging is too high, return to the first one
 122         if (this.pagination.currentPage > 1 && totalVideos <= ((this.pagination.currentPage - 1) * this.pagination.itemsPerPage)) {
 123           this.pagination.currentPage = 1
 124           this.setNewRouteParams()
 125           return this.reloadVideos()
 126         }
 127
 128         this.loadedPages[page] = videos
 129         this.buildVideoPages()
 130         this.pagination.totalItems = totalVideos
 131
 132         // Initialize infinite scroller now we loaded the first page
 133         if (Object.keys(this.loadedPages).length === 1) {
 134           // Wait elements creation
 135           setTimeout(() => {
 136             this.infiniteScroller.initialize()
 137
 138             // At our first load, we did not load the first page
 139             // Load the previous page so the user can move on the top (and browser previous pages)
 140             if (this.pagination.currentPage > 1) this.loadMoreVideos(this.pagination.currentPage - 1, true)
 141           }, 500)
 142         }
 143
 144         // Insert elements on the top but keep the scroll in the previous position
 145         if (loadOnTop) setTimeout(() => { window.scrollTo(0, currentY + this.pageHeight) }, 0)
 146       },
 147       error => {
 148         this.loadingPage[page] = false
 149         this.notificationsService.error(this.i18n('Error'), error.message)
 150       }
 151     )
 152   }
 153
 154   protected hasMoreVideos () {
 155     // No results
 156     if (this.pagination.totalItems === 0) return false
 157
 158     // Not loaded yet
 159     if (!this.pagination.totalItems) return true
 160
 161     const maxPage = this.pagination.totalItems / this.pagination.itemsPerPage
 162     return maxPage > this.maxPageLoaded()
 163   }
 164
 165   protected previousPage () {
 166     const min = this.minPageLoaded()
 167
 168     if (min > 1) {
 169       this.loadMoreVideos(min - 1)
 170     }
 171   }
 172
 173   protected nextPage () {
 174     this.loadMoreVideos(this.maxPageLoaded() + 1)
 175   }
 176
 177   protected buildRouteParams () {
 178     // There is always a sort and a current page
 179     const params = {
 180       sort: this.sort,
 181       page: this.pagination.currentPage
 182     }
 183
 184     return Object.assign(params, this.otherRouteParams)
 185   }
 186
 187   protected loadRouteParams (routeParams: { [ key: string ]: any }) {
 188     this.sort = routeParams['sort'] as VideoSortField || this.defaultSort
 189     this.categoryOneOf = routeParams['categoryOneOf']
 190     if (routeParams['page'] !== undefined) {
 191       this.pagination.currentPage = parseInt(routeParams['page'], 10)
 192     } else {
 193       this.pagination.currentPage = 1
 194     }
 195   }
 196
 197   protected setNewRouteParams () {
 198     const paramsObject = this.buildRouteParams()
 199
 200     const queryParams = Object.keys(paramsObject).map(p => p + '=' + paramsObject[p]).join('&')
 201     this.location.replaceState(this.currentRoute, queryParams)
 202   }
 203
 204   protected buildVideoPages () {
 205     this.videoPages = Object.values(this.loadedPages)
 206   }
 207
 208   protected adjustVideoPageHeight () {
 209     const numberOfPagesLoaded = Object.keys(this.loadedPages).length
 210     if (!numberOfPagesLoaded) return
 211
 212     this.pageHeight = this.videosElement.nativeElement.offsetHeight / numberOfPagesLoaded
 213   }
 214
 215   protected buildVideoHeight () {
 216     // Same ratios than base width/height
 217     return this.videosElement.nativeElement.offsetWidth * (this.baseVideoHeight / this.baseVideoWidth)
 218   }
 219
 220   private minPageLoaded () {
 221     return Math.min(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 222   }
 223
 224   private maxPageLoaded () {
 225     return Math.max(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 226   }
 227
 228   private calcPageSizes () {
 229     if (this.screenService.isInMobileView() || this.baseVideoWidth === -1) {
 230       this.pagination.itemsPerPage = 5
 231
 232       // Video takes all the width
 233       this.videoWidth = -1
 234       this.videoHeight = this.buildVideoHeight()
 235       this.pageHeight = this.pagination.itemsPerPage * this.videoHeight
 236     } else {
 237       this.videoWidth = this.baseVideoWidth
 238       this.videoHeight = this.baseVideoHeight
 239
 240       const videosWidth = this.videosElement.nativeElement.offsetWidth
 241       this.pagination.itemsPerPage = Math.floor(videosWidth / this.videoWidth) * AbstractVideoList.LINES_PER_PAGE
 242       this.pageHeight = this.videoHeight * AbstractVideoList.LINES_PER_PAGE
 243     }
 244
 245     // Rebuild pages because maybe we modified the number of items per page
 246     const videos = [].concat(...this.videoPages)
 247     this.loadedPages = {}
 248
 249     let i = 1
 250     // Don't include the last page if it not complete
 251     while (videos.length >= this.pagination.itemsPerPage && i < 10000) { // 10000 -> Hard limit in case of infinite loop
 252       this.loadedPages[i] = videos.splice(0, this.pagination.itemsPerPage)
 253       i++
 254     }
 255
 256     // Re fetch the last page
 257     if (videos.length !== 0) {
 258       this.loadMoreVideos(i)
 259     } else {
 260       this.buildVideoPages()
 261     }
 262
 263     console.log('Rebuilt pages with %s elements per page.', this.pagination.itemsPerPage)
 264   }
 265 }