/** * {@inheritdoc} */ public function form(array $form, FormStateInterface $form_state) { $form = parent::form($form, $form_state); $event_definitions = $this->eventManager->getGroupedDefinitions(); $options = []; foreach ($event_definitions as $group => $definitions) { foreach ($definitions as $id => $definition) { $options[$group][$id] = $definition['label']; } } $form['event'] = ['#type' => 'select', '#title' => $this->t('React on event'), '#options' => $options, '#required' => TRUE, '#empty_value' => $this->t('- Select -'), '#description' => $this->t('Whenever the event occurs, rule evaluation is triggered.')]; return $form; }