client/src/app/shared/video/abstract-video-list.ts

   1 import { ElementRef, OnDestroy, OnInit, ViewChild } from '@angular/core'
   2 import { ActivatedRoute, Router } from '@angular/router'
   3 import { Location } from '@angular/common'
   4 import { isInMobileView } from '@app/shared/misc/utils'
   5 import { InfiniteScrollerDirective } from '@app/shared/video/infinite-scroller.directive'
   6 import { NotificationsService } from 'angular2-notifications'
   7 import 'rxjs/add/operator/debounceTime'
   8 import { Observable } from 'rxjs/Observable'
   9 import { fromEvent } from 'rxjs/observable/fromEvent'
  10 import { Subscription } from 'rxjs/Subscription'
  11 import { AuthService } from '../../core/auth'
  12 import { ComponentPagination } from '../rest/component-pagination.model'
  13 import { VideoSortField } from './sort-field.type'
  14 import { Video } from './video.model'
  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 = '-createdAt'
  28   defaultSort: VideoSortField = '-createdAt'
  29   syndicationItems = []
  30
  31   loadOnInit = true
  32   marginContent = true
  33   pageHeight: number
  34   videoWidth: number
  35   videoHeight: number
  36   videoPages: Video[][] = []
  37
  38   protected baseVideoWidth = 215
  39   protected baseVideoHeight = 230
  40
  41   protected abstract notificationsService: NotificationsService
  42   protected abstract authService: AuthService
  43   protected abstract router: Router
  44   protected abstract route: ActivatedRoute
  45   protected abstract location: Location
  46   protected abstract currentRoute: string
  47   abstract titlePage: string
  48
  49   protected loadedPages: { [ id: number ]: Video[] } = {}
  50   protected otherRouteParams = {}
  51
  52   private resizeSubscription: Subscription
  53
  54   abstract getVideosObservable (page: number): Observable<{ videos: Video[], totalVideos: number}>
  55   abstract generateSyndicationList ()
  56
  57   get user () {
  58     return this.authService.getUser()
  59   }
  60
  61   ngOnInit () {
  62     // Subscribe to route changes
  63     const routeParams = this.route.snapshot.queryParams
  64     this.loadRouteParams(routeParams)
  65
  66     this.resizeSubscription = fromEvent(window, 'resize')
  67       .debounceTime(500)
  68       .subscribe(() => this.calcPageSizes())
  69
  70     this.calcPageSizes()
  71     if (this.loadOnInit === true) this.loadMoreVideos(this.pagination.currentPage)
  72   }
  73
  74   ngOnDestroy () {
  75     if (this.resizeSubscription) this.resizeSubscription.unsubscribe()
  76   }
  77
  78   onNearOfTop () {
  79     this.previousPage()
  80   }
  81
  82   onNearOfBottom () {
  83     if (this.hasMoreVideos()) {
  84       this.nextPage()
  85     }
  86   }
  87
  88   onPageChanged (page: number) {
  89     this.pagination.currentPage = page
  90     this.setNewRouteParams()
  91   }
  92
  93   reloadVideos () {
  94     this.loadedPages = {}
  95     this.loadMoreVideos(this.pagination.currentPage)
  96   }
  97
  98   loadMoreVideos (page: number) {
  99     if (this.loadedPages[page] !== undefined) return
 100
 101     const observable = this.getVideosObservable(page)
 102
 103     observable.subscribe(
 104       ({ videos, totalVideos }) => {
 105         // Paging is too high, return to the first one
 106         if (this.pagination.currentPage > 1 && totalVideos <= ((this.pagination.currentPage - 1) * this.pagination.itemsPerPage)) {
 107           this.pagination.currentPage = 1
 108           this.setNewRouteParams()
 109           return this.reloadVideos()
 110         }
 111
 112         this.loadedPages[page] = videos
 113         this.buildVideoPages()
 114         this.pagination.totalItems = totalVideos
 115
 116         // Initialize infinite scroller now we loaded the first page
 117         if (Object.keys(this.loadedPages).length === 1) {
 118           // Wait elements creation
 119           setTimeout(() => this.infiniteScroller.initialize(), 500)
 120         }
 121       },
 122       error => this.notificationsService.error('Error', error.message)
 123     )
 124   }
 125
 126   protected hasMoreVideos () {
 127     // No results
 128     if (this.pagination.totalItems === 0) return false
 129
 130     // Not loaded yet
 131     if (!this.pagination.totalItems) return true
 132
 133     const maxPage = this.pagination.totalItems / this.pagination.itemsPerPage
 134     return maxPage > this.maxPageLoaded()
 135   }
 136
 137   protected previousPage () {
 138     const min = this.minPageLoaded()
 139
 140     if (min > 1) {
 141       this.loadMoreVideos(min - 1)
 142     }
 143   }
 144
 145   protected nextPage () {
 146     this.loadMoreVideos(this.maxPageLoaded() + 1)
 147   }
 148
 149   protected buildRouteParams () {
 150     // There is always a sort and a current page
 151     const params = {
 152       sort: this.sort,
 153       page: this.pagination.currentPage
 154     }
 155
 156     return Object.assign(params, this.otherRouteParams)
 157   }
 158
 159   protected loadRouteParams (routeParams: { [ key: string ]: any }) {
 160     this.sort = routeParams['sort'] as VideoSortField || this.defaultSort
 161
 162     if (routeParams['page'] !== undefined) {
 163       this.pagination.currentPage = parseInt(routeParams['page'], 10)
 164     } else {
 165       this.pagination.currentPage = 1
 166     }
 167   }
 168
 169   protected setNewRouteParams () {
 170     const paramsObject = this.buildRouteParams()
 171
 172     const queryParams = Object.keys(paramsObject).map(p => p + '=' + paramsObject[p]).join('&')
 173     this.location.replaceState(this.currentRoute, queryParams)
 174   }
 175
 176   protected buildVideoPages () {
 177     this.videoPages = Object.values(this.loadedPages)
 178   }
 179
 180   protected buildVideoHeight () {
 181     // Same ratios than base width/height
 182     return this.videosElement.nativeElement.offsetWidth * (this.baseVideoHeight / this.baseVideoWidth)
 183   }
 184
 185   private minPageLoaded () {
 186     return Math.min(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 187   }
 188
 189   private maxPageLoaded () {
 190     return Math.max(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 191   }
 192
 193   private calcPageSizes () {
 194     if (isInMobileView() || this.baseVideoWidth === -1) {
 195       this.pagination.itemsPerPage = 5
 196
 197       // Video takes all the width
 198       this.videoWidth = -1
 199       this.videoHeight = this.buildVideoHeight()
 200       this.pageHeight = this.pagination.itemsPerPage * this.videoHeight
 201     } else {
 202       this.videoWidth = this.baseVideoWidth
 203       this.videoHeight = this.baseVideoHeight
 204
 205       const videosWidth = this.videosElement.nativeElement.offsetWidth
 206       this.pagination.itemsPerPage = Math.floor(videosWidth / this.videoWidth) * AbstractVideoList.LINES_PER_PAGE
 207       this.pageHeight = this.videoHeight * AbstractVideoList.LINES_PER_PAGE
 208     }
 209
 210     // Rebuild pages because maybe we modified the number of items per page
 211     const videos = [].concat(...this.videoPages)
 212     this.loadedPages = {}
 213
 214     let i = 1
 215     // Don't include the last page if it not complete
 216     while (videos.length >= this.pagination.itemsPerPage && i < 10000) { // 10000 -> Hard limit in case of infinite loop
 217       this.loadedPages[i] = videos.splice(0, this.pagination.itemsPerPage)
 218       i++
 219     }
 220
 221     // Re fetch the last page
 222     if (videos.length !== 0) {
 223       this.loadMoreVideos(i)
 224     } else {
 225       this.buildVideoPages()
 226     }
 227
 228     console.log('Rebuilt pages with %s elements per page.', this.pagination.itemsPerPage)
 229   }
 230 }