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

   1 import { ElementRef, OnInit, ViewChild } from '@angular/core'
   2 import { ActivatedRoute, Router } from '@angular/router'
   3 import { isInMobileView } from '@app/shared/misc/utils'
   4 import { InfiniteScrollerDirective } from '@app/shared/video/infinite-scroller.directive'
   5 import { NotificationsService } from 'angular2-notifications'
   6 import { Observable } from 'rxjs/Observable'
   7 import { fromEvent } from 'rxjs/observable/fromEvent'
   8 import { AuthService } from '../../core/auth'
   9 import { ComponentPagination } from '../rest/component-pagination.model'
  10 import { SortField } from './sort-field.type'
  11 import { Video } from './video.model'
  12
  13 export abstract class AbstractVideoList implements OnInit {
  14   private static LINES_PER_PAGE = 3
  15
  16   @ViewChild('videoElement') videosElement: ElementRef
  17   @ViewChild(InfiniteScrollerDirective) infiniteScroller: InfiniteScrollerDirective
  18
  19   pagination: ComponentPagination = {
  20     currentPage: 1,
  21     itemsPerPage: 10,
  22     totalItems: null
  23   }
  24   sort: SortField = '-createdAt'
  25   defaultSort: SortField = '-createdAt'
  26   loadOnInit = true
  27   pageHeight: number
  28   videoWidth = 215
  29   videoHeight = 230
  30   videoPages: Video[][]
  31
  32   protected abstract notificationsService: NotificationsService
  33   protected abstract authService: AuthService
  34   protected abstract router: Router
  35   protected abstract route: ActivatedRoute
  36   protected abstract currentRoute: string
  37   abstract titlePage: string
  38
  39   protected loadedPages: { [ id: number ]: Video[] } = {}
  40   protected otherRouteParams = {}
  41
  42   abstract getVideosObservable (page: number): Observable<{ videos: Video[], totalVideos: number}>
  43
  44   get user () {
  45     return this.authService.getUser()
  46   }
  47
  48   ngOnInit () {
  49     // Subscribe to route changes
  50     const routeParams = this.route.snapshot.params
  51     this.loadRouteParams(routeParams)
  52
  53     fromEvent(window, 'resize')
  54       .debounceTime(500)
  55       .subscribe(() => this.calcPageSizes())
  56
  57     this.calcPageSizes()
  58     if (this.loadOnInit === true) this.loadMoreVideos(this.pagination.currentPage)
  59   }
  60
  61   onNearOfTop () {
  62     this.previousPage()
  63   }
  64
  65   onNearOfBottom () {
  66     if (this.hasMoreVideos()) {
  67       this.nextPage()
  68     }
  69   }
  70
  71   onPageChanged (page: number) {
  72     this.pagination.currentPage = page
  73     this.setNewRouteParams()
  74   }
  75
  76   reloadVideos () {
  77     this.loadedPages = {}
  78     this.loadMoreVideos(this.pagination.currentPage)
  79   }
  80
  81   loadMoreVideos (page: number) {
  82     if (this.loadedPages[page] !== undefined) return
  83
  84     const observable = this.getVideosObservable(page)
  85
  86     observable.subscribe(
  87       ({ videos, totalVideos }) => {
  88         // Paging is too high, return to the first one
  89         if (this.pagination.currentPage > 1 && totalVideos <= ((this.pagination.currentPage - 1) * this.pagination.itemsPerPage)) {
  90           this.pagination.currentPage = 1
  91           this.setNewRouteParams()
  92           return this.reloadVideos()
  93         }
  94
  95         this.loadedPages[page] = videos
  96         this.buildVideoPages()
  97         this.pagination.totalItems = totalVideos
  98
  99         // Initialize infinite scroller now we loaded the first page
 100         if (Object.keys(this.loadedPages).length === 1) {
 101           // Wait elements creation
 102           setTimeout(() => this.infiniteScroller.initialize(), 500)
 103         }
 104       },
 105       error => this.notificationsService.error('Error', error.message)
 106     )
 107   }
 108
 109   protected hasMoreVideos () {
 110     // No results
 111     if (this.pagination.totalItems === 0) return false
 112
 113     // Not loaded yet
 114     if (!this.pagination.totalItems) return true
 115
 116     const maxPage = this.pagination.totalItems / this.pagination.itemsPerPage
 117     return maxPage > this.maxPageLoaded()
 118   }
 119
 120   protected previousPage () {
 121     const min = this.minPageLoaded()
 122
 123     if (min > 1) {
 124       this.loadMoreVideos(min - 1)
 125     }
 126   }
 127
 128   protected nextPage () {
 129     this.loadMoreVideos(this.maxPageLoaded() + 1)
 130   }
 131
 132   protected buildRouteParams () {
 133     // There is always a sort and a current page
 134     const params = {
 135       sort: this.sort,
 136       page: this.pagination.currentPage
 137     }
 138
 139     return Object.assign(params, this.otherRouteParams)
 140   }
 141
 142   protected loadRouteParams (routeParams: { [ key: string ]: any }) {
 143     this.sort = routeParams['sort'] as SortField || this.defaultSort
 144
 145     if (routeParams['page'] !== undefined) {
 146       this.pagination.currentPage = parseInt(routeParams['page'], 10)
 147     } else {
 148       this.pagination.currentPage = 1
 149     }
 150   }
 151
 152   protected setNewRouteParams () {
 153     const routeParams = this.buildRouteParams()
 154     this.router.navigate([ this.currentRoute, routeParams ])
 155   }
 156
 157   protected buildVideoPages () {
 158     this.videoPages = Object.values(this.loadedPages)
 159   }
 160
 161   private minPageLoaded () {
 162     return Math.min(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 163   }
 164
 165   private maxPageLoaded () {
 166     return Math.max(...Object.keys(this.loadedPages).map(e => parseInt(e, 10)))
 167   }
 168
 169   private calcPageSizes () {
 170     if (isInMobileView()) {
 171       this.pagination.itemsPerPage = 5
 172
 173       // Video takes all the width
 174       this.videoWidth = -1
 175       this.pageHeight = this.pagination.itemsPerPage * this.videoHeight
 176     } else {
 177       const videosWidth = this.videosElement.nativeElement.offsetWidth
 178       this.pagination.itemsPerPage = Math.floor(videosWidth / this.videoWidth) * AbstractVideoList.LINES_PER_PAGE
 179       this.pageHeight = this.videoHeight * AbstractVideoList.LINES_PER_PAGE
 180     }
 181
 182     // Rebuild pages because maybe we modified the number of items per page
 183     let videos: Video[] = []
 184     Object.values(this.loadedPages)
 185       .forEach(videosPage => videos = videos.concat(videosPage))
 186     this.loadedPages = {}
 187
 188     for (let i = 1; (i * this.pagination.itemsPerPage) <= videos.length; i++) {
 189       this.loadedPages[i] = videos.slice((i - 1) * this.pagination.itemsPerPage, this.pagination.itemsPerPage * i)
 190     }
 191
 192     this.buildVideoPages()
 193
 194     console.log('Re calculated pages after a resize!')
 195   }
 196 }