drupal-media / entity_browser

    if (($trigger = $form_state->getTriggeringElement()) && in_array($this->fieldDefinition->getName(), $trigger['#parents'])) {

      // Submit was triggered by hidden "target_id" element when entities were

      // added via entity browser.

      if (!empty($trigger['#ajax']['event']) && $trigger['#ajax']['event'] == 'entity_browser_value_updated') {

        $parents = $trigger['#parents'];

      }

      // Submit was triggered by one of the "Remove" buttons. We need to walk

      // few levels up to read value of "target_id" element.

      elseif ($trigger['#type'] == 'submit' && strpos($trigger['#name'], $this->fieldDefinition->getName() . '_remove_') === 0) {

        $parents = array_merge(array_slice($trigger['#parents'], 0, -4), ['target_id']);

      }

      if (isset($parents) && $value = $form_state->getValue($parents)) {

        $ids = explode(' ', $value);

    // are added or by one of the "Remove" buttons. Depending on that we need to

    // figure out where root of the widget is in the form structure and use this

    // information to return correct part of the form.

    if (!empty($trigger['#ajax']['event']) && $trigger['#ajax']['event'] == 'entity_browser_value_updated') {

      $parents = array_slice($trigger['#array_parents'], 0, -2);

    }

    elseif ($trigger['#type'] == 'submit' && strpos($trigger['#name'], '_remove_')) {

      $parents = array_slice($trigger['#array_parents'], 0, -4);

    }

    return NestedArray::getValue($form, $parents);

  }