I have a configuration form for a Condition plugin I want to have ajax in. When selecting from this field, I want to get a list of displays for that View:

public function buildConfigurationForm(array $form, FormStateInterface $form_state) { $form = parent::buildConfigurationForm($form, $form_state); $views = $this->entityTypeManager->getStorage(‘view’)->loadMultiple(); $options = [];

/** @var DrupalviewsViews $view */ foreach ($views as $view) {   $options[$view->id()] = $view->label(); }  $form['#prefix'] = '<div id="views-settings">'; $form['#suffix'] = '</div>';  $view_id = $form_state->getValue('view_id');  if (empty($view_id)) {   $view_id = $form_state->getUserInput()["conditions"]["sfp_condition_view_not_empty"]["view_id"] ?? NULL; }  if (empty($view_id)) {   $view_id = $this->configuration['view_id'] ?? NULL; }  $displays = isset($view_id) ? $this->getViewsDisplays($view_id) : [];  $form['view_id'] = [   '#type' => 'select',   '#title' => $this->t('View'),   '#required' => TRUE,   '#options' => $options,   '#default_value' => $view_id ? $options[$view_id] : '',   '#ajax' => [     'wrapper' => 'views-settings',     'callback' => '::updateViewsDisplay',     'event' => 'change',   ], ];  if (!empty($displays)) {   $form['view_display'] = [     '#type' => 'select',     '#title' => $this->t('View display'),     '#required' => TRUE,     '#options' => $displays,     '#default_value' => $displays[$this->configuration['view_display']] ?? $displays['default'],   ]; }  return $form; 

}

  /**    * Trigger form rebuild.    *    * @param array $form    * @param DrupalCoreFormFormStateInterface $form_state    * @return array    */   public function updateViewsDisplay(array $form, FormStateInterface $form_state) {     return $form;   } 

Xdebug hits the method fine, but I get this AJAX error:

"The specified #ajax callback is empty or not callable."

and nothing happens after that.

I checked elsewhere where I have done this and the only difference I can see is the ones that worked are regular Drupal Form API forms, and this is a plugin form passed from buildConfigurationForm. Outside of that, I am not seeing the issue.