<script>
  import { __ } from '~/locale';
  /**
   * Port of detail_behavior expand button.
   *
   * @example
   * <expand-button>
   *   <template slot="expanded">
   *      Text goes here.
   *    </template>
   * </expand-button>
   */
  export default {
    name: 'ExpandButton',
    data() {
      return {
        isCollapsed: true,
      };
    },
    computed: {
      ariaLabel() {
        return __('Click to expand text');
      },
    },
    methods: {
      onClick() {
        this.isCollapsed = !this.isCollapsed;
      },
    },
  };
</script>
<template>
  <span>
    <button
      type="button"
      v-show="isCollapsed"
      class="text-expander btn-blank"
      :aria-label="ariaLabel"
      @click="onClick">
      ...
    </button>
    <span v-show="!isCollapsed">
      <slot name="expanded"></slot>
    </span>
  </span>
</template>

<script>
  import { __ } from '~/locale';
  /**
   * Port of detail_behavior expand button.
   *
   * @example
   * <expand-button>
   *   <template slot="expanded">
   *      Text goes here.
   *    </template>
   * </expand-button>
   */
  export default {
    name: 'ExpandButton',
    data() {
      return {
        isCollapsed: true,
      };
    },
    computed: {
      ariaLabel() {
        return __('Click to expand text');
      },
    },
    methods: {
      onClick() {
        this.isCollapsed = !this.isCollapsed;
      },
    },
  };
</script>
<template>
  <span>
    <button
      type="button"
      v-show="isCollapsed"
      class="text-expander btn-blank"
      :aria-label="ariaLabel"
      @click="onClick">
      ...
    </button>
    <span v-if="!isCollapsed">
      <slot name="expanded"></slot>
    </span>
  </span>
</template>

Use v-if in the expand button for performance
Use v-if in the expand button for performance
