pinafore/routes/_components/status/StatusSpoiler.html

<div class="status-spoiler {{isStatusInNotification ? 'status-in-notification' : ''}}">
  {{status.spoiler_text}}
</div>
<div class="status-spoiler-button">
  <button type="button" on:click="onClickSpoilerButton()">
    {{spoilerShown ? 'Show less' : 'Show more'}}
  </button>
</div>
<style>
  .status-spoiler {
    grid-area: status-spoiler;
    word-wrap: break-word;
    overflow: hidden;
    white-space: pre-wrap;
    font-size: 1.1em;
    margin: 5px;
  }

  .status-spoiler-button {
    grid-area: status-spoiler-button;
    margin: 5px;
  }

  .status-spoiler-button button {
    padding: 5px 10px;
    font-size: 1.1em;
  }

  .status-spoiler.status-in-notification {
    color: var(--very-deemphasized-text-color);
  }
</style>
<script>
  import { store } from '../../_store/store'

  export default {
    store: () => store,
    computed: {
      spoilerShown: ($spoilersShown, contextualStatusId) => !!$spoilersShown[contextualStatusId]
    },
    methods: {
      onClickSpoilerButton() {
        let contextualStatusId = this.get('contextualStatusId')
        let $spoilersShown = this.store.get('spoilersShown')
        $spoilersShown[contextualStatusId] = !$spoilersShown[contextualStatusId]
        this.store.set({'spoilersShown': $spoilersShown})
        this.fire('recalculateHeight')
      }
    }
  }
</script>