Type checking

gistfile1.twig

{% property 'expandable' with { type: 'boolean', required: true } %}
{% property 'expanded' with { type: 'boolean', required: true } %}
{% property 'toggle' with { type: 'function' } %}
{% property 'modifier' with { type: 'string' } %}

{% property 'children' with { type: 'node', required: true } %}
{% property 'title' with { type: 'node' } %}

<div
  class={{ "box box--" + modifier }}
  expandable={{ expandable }}
  expanded={{ expanded }}>
  {% if title %}
    <div class="box__title">
      {{ title }}
    </div>
  {% endif %}
  <div class="box__body">
    {{ children }}
  </div>
  {% if expandable %}
    <div class="box__footer">
      <button onClick={{ toggle }}>{{ expanded ? 'less' : 'more' }}</button>
    </div>
  {% endif %}
</div>