drupal/core/modules/system/templates/form-element.html.twig

{#
/**
 * @file
 * Default theme implementation for a form element.
 *
 * Available variables:
 * - attributes: HTML attributes for the containing element.
 * - prefix: (optional) The form element prefix, may not be set.
 * - suffix: (optional) The form element suffix, may not be set.
 * - required: The required marker, or empty if the associated form element is
 *   not required.
 * - label: A rendered label element.
 * - label_display: Label display setting. It can have these values:
 *   - before: The label is output before the element. This is the default.
 *     The label includes the #title and the required marker, if #required.
 *   - after: The label is output after the element. For example, this is used
 *     for radio and checkbox #type elements. If the #title is empty but the
 *     field is #required, the label will contain only the required marker.
 *   - invisible: Labels are critical for screen readers to enable them to
 *     properly navigate through forms but can be visually distracting. This
 *     property hides the label for everyone except screen readers.
 *   - attribute: Set the title attribute on the element to create a tooltip but
 *     output no label element. This is supported only for checkboxes and radios
 *     in \Drupal\Core\Render\Element\CompositeFormElementTrait::preRenderCompositeFormElement().
 *     It is used where a visual label is not needed, such as a table of
 *     checkboxes where the row and column provide the context. The tooltip will
 *     include the title and required marker.
 * - description: (optional) A list of description properties containing:
 *    - content: A description of the form element, may not be set.
 *    - attributes: (optional) A list of HTML attributes to apply to the
 *      description content wrapper. Will only be set when description is set.
 * - description_display: Description display setting. It can have these values:
 *   - before: The description is output before the element.
 *   - after: The description is output after the element. This is the default
 *     value.
 *   - invisible: The description is output after the element, hidden visually
 *     but available to screen readers.
 *
 * @see template_preprocess_form_element()
 *
 * @ingroup themeable
 */
#}
<div{{ attributes }}>
  {% if label_display in ['before', 'invisible'] %}
    {{ label }}
  {% endif %}
  {% if prefix is not empty %}
    <span class="field-prefix">{{ prefix }}</span>
  {% endif %}
  {% if description_display == 'before' and description.content %}
    <div{{ description.attributes }}>
      {{ description.content }}
    </div>
  {% endif %}
  {{ children }}
  {% if suffix is not empty %}
    <span class="field-suffix">{{ suffix }}</span>
  {% endif %}
  {% if label_display == 'after' %}
    {{ label }}
  {% endif %}
  {% if description_display in ['after', 'invisible'] and description.content %}
    <div{{ description.attributes }}>
      {{ description.content }}
    </div>
  {% endif %}
</div>