EntityAutocomplete::valueCallback

public static EntityAutocomplete::valueCallback(&$element, $input, FormStateInterface $form_state)

public static function valueCallback(&$element, $input, FormStateInterface $form_state) {
  // Process the #default_value property.
  if ($input === FALSE && isset($element['#default_value']) && $element['#process_default_value']) {
    if (is_array($element['#default_value']) && $element['#tags'] !== TRUE) {
      throw new \InvalidArgumentException('The #default_value property is an array but the form element does not allow multiple values.');
    }
    elseif (!empty($element['#default_value']) && !is_array($element['#default_value'])) {
      // Convert the default value into an array for easier processing in
      // static::getEntityLabels().
      $element['#default_value'] = array($element['#default_value']);
    }

    if ($element['#default_value']) {
      if (!(reset($element['#default_value']) instanceof EntityInterface)) {
        throw new \InvalidArgumentException('The #default_value property has to be an entity object or an array of entity objects.');
      }

      // Extract the labels from the passed-in entity objects, taking access
      // checks into account.
      return static::getEntityLabels($element['#default_value']);
    }
  }

  // Potentially the #value is set directly, so it contains the 'target_id'
  // array structure instead of a string.
  if ($input !== FALSE && is_array($input)) {
    $entity_ids = array_map(function(array $item) {
      return $item['target_id'];
    }, $input);

    $entities = \Drupal::entityTypeManager()->getStorage($element['#target_type'])->loadMultiple($entity_ids);

    return static::getEntityLabels($entities);
  }
}