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