open-nomad/ui/app/templates/components/multi-select-dropdown.hbs

<BasicDropdown
  @horizontalPosition="left"
  @onOpen={{action (queue (action (mut isOpen) true) (action capture))}}
  @onClose={{action (mut isOpen) false}} as |dd|
>
  <dd.Trigger data-test-dropdown-trigger class="dropdown-trigger" {{on "keydown" (action "openOnArrowDown" dd)}}>
    <div class="dropdown-trigger-label">
      {{label}}
      {{#if selection.length}}
        <span data-test-dropdown-count class="tag is-light">
          {{selection.length}}
        </span>
      {{/if}}
    </div>
    <span class="dropdown-trigger-icon ember-power-select-status-icon"></span>
  </dd.Trigger>
  <dd.Content class="dropdown-options">
    <ul role="listbox" data-test-dropdown-options>
      {{#each options key="key" as |option|}}
        <li
          data-test-dropdown-option={{option.key}}
          class="dropdown-option"
          tabindex="1"
          onkeydown={{action "traverseList" option}}
        >
          <label>
            <input
              type="checkbox"
              tabindex="-1"
              checked={{contains option.key selection}}
              onchange={{action "toggle" option}}
            />
            {{option.label}}
          </label>
        </li>
      {{else}}
        <em data-test-dropdown-empty class="dropdown-empty">
          No options
        </em>
      {{/each}}
    </ul>
  </dd.Content>
</BasicDropdown>