semaphore/routes/_components/timeline/Timeline.html

<div class="timeline" role="feed" aria-label="{{label}}">
  <VirtualList component="{{StatusListItem}}"
               :makeProps
               items="{{$statusIds}}"
               on:scrollToBottom="onScrollToBottom()"
               shown="{{$initialized}}"
               footerComponent="{{LoadingFooter}}"
               showFooter="{{$initialized && $runningUpdate}}"
               realm="{{$currentInstance + '/' + timeline}}"
               on:initializedVisibleItems="initialize()"
  />
</div>
<style>
  .timeline {
    min-height: 60vh;
  }
</style>
<script>
  import { store } from '../../_store/store'
  import StatusListItem from './StatusListItem.html'
  import LoadingFooter from './LoadingFooter.html'
  import VirtualList from '../virtualList/VirtualList.html'
  import { timelines } from '../../_static/timelines'
  import { database } from '../../_utils/database/database'
  import { initializeTimeline, fetchStatusesOnScrollToBottom, setupTimeline } from '../../_actions/timeline'

  export default {
    async oncreate() {
      setupTimeline()
    },
    data: () => ({
      StatusListItem: StatusListItem,
      LoadingFooter: LoadingFooter
    }),
    computed: {
      makeProps: ($currentInstance, timelineType, timelineValue) => async (statusId) => ({
        timelineType: timelineType,
        timelineValue: timelineValue,
        status: await database.getStatus($currentInstance, statusId)
      }),
      label: (timeline, $currentInstance, timelineType, timelineValue) => {
        if (timelines[timeline]) {
          return `${timelines[timeline].label} timeline for ${$currentInstance}`
        }

        switch (timelineType) {
          case 'tag':
            return `#${timelineValue} timeline for ${$currentInstance}`
          case 'status':
            return 'Status context'
          case 'account':
            return `Account #${timelineValue} on ${$currentInstance}`
        }
      },
      timelineType: (timeline) => {
        return timeline.split('/')[0]
      },
      timelineValue: (timeline) => {
        return timeline.split('/').slice(-1)[0]
      }
    },
    store: () => store,
    components: {
      VirtualList
    },
    methods: {
      initialize() {
        if (this.store.get('initialized') || !this.store.get('statusIds') || !this.store.get('statusIds').length) {
          return
        }
        initializeTimeline()
      },
      onScrollToBottom() {
        if (!this.store.get('initialized') ||
            this.store.get('runningUpdate') ||
            this.get('timelineType') === 'status') { // for status contexts, we've already fetched the whole thread
          return
        }
        fetchStatusesOnScrollToBottom()
      }
    }
  }
</script>