View source  
  <?php
namespace Drupal\social_event_invite\Form;
use Drupal\social_event\EventEnrollmentInterface;
use Drupal\social_event\Form\EnrollActionForm;
use Drupal\Core\Form\FormStateInterface;
use Drupal\node\Entity\Node;
use Drupal\Core\Cache\Cache;
class EventInviteEnrollActionForm extends EnrollActionForm {
  
  public function getFormId() {
    return 'event_invite_enroll_action_form';
  }
  
  public function buildForm(array $form, FormStateInterface $form_state, Node $node = NULL) {
    $form = parent::buildForm($form, $form_state);
    $nid = $this->routeMatch
      ->getRawParameter('node');
    $current_user = $this->currentUser;
    $uid = $current_user
      ->id();
    if (!$current_user
      ->isAnonymous()) {
      
      if (!$this->eventEnrollService
        ->isEnabled($node)) {
        return [];
      }
      $conditions = [
        'field_account' => $uid,
        'field_event' => $nid,
      ];
      $enrollments = $this->entityStorage
        ->loadByProperties($conditions);
      
      if (empty($enrollments)) {
        if ((int) $node->field_enroll_method->value === EventEnrollmentInterface::ENROLL_METHOD_INVITE && social_event_manager_or_organizer() === FALSE) {
          return [];
        }
      }
      elseif ($enrollment = array_pop($enrollments)) {
        $enroll_request_status = $enrollment->field_request_or_invite_status->value;
        
        if ($enroll_request_status == '4') {
          $submit_text = $this
            ->t('Accept');
          $form['enroll_for_this_event'] = [
            '#type' => 'submit',
            '#value' => $submit_text,
            '#name' => 'accept_invite',
          ];
          
          $form['enroll_for_this_event']['#attributes'] = [
            'class' => [
              'btn',
              'btn-accent brand-bg-accent',
              'btn-lg btn-raised',
              'dropdown-toggle',
              'waves-effect',
            ],
          ];
          
          $form['event_id'] = [
            '#type' => 'hidden',
            '#value' => $this->routeMatch
              ->getRawParameter('node'),
          ];
          $form['decline_invite'] = [
            '#type' => 'submit',
            '#value' => '',
            '#name' => 'decline_invite',
          ];
          
          $form['decline_invite']['#attributes'] = [
            'class' => [
              'btn',
              'btn-accent brand-bg-accent',
              'btn-lg btn-raised',
              'dropdown-toggle',
              'waves-effect',
              'margin-left-s',
            ],
            'autocomplete' => 'off',
            'data-toggle' => 'dropdown',
            'aria-haspopup' => 'true',
            'aria-expanded' => 'false',
            'data-caret' => 'true',
          ];
          $decline_text = $this
            ->t('Decline');
          
          $form['decline_invite_dropdown'] = [
            '#markup' => '<ul class="dropdown-menu dropdown-menu-right"><li><a href="#" class="enroll-form-submit"> ' . $decline_text . ' </a></li></ul>',
          ];
          
          $form['operation'] = [
            '#type' => 'hidden',
            '#default_value' => '',
          ];
          $form['#attached']['library'][] = 'social_event/form_submit';
        }
      }
    }
    
    if ($current_user
      ->isAnonymous()) {
      unset($form['enroll_for_this_event']);
    }
    return $form;
  }
  
  public function submitForm(array &$form, FormStateInterface $form_state) {
    parent::submitForm($form, $form_state);
    $operation = $form_state
      ->getValue('operation');
    $current_user = $this->currentUser;
    $uid = $current_user
      ->id();
    $nid = $form_state
      ->getValue('event') ?? $this->routeMatch
      ->getRawParameter('node');
    $conditions = [
      'field_account' => $uid,
      'field_event' => $nid,
    ];
    $enrollments = $this->entityStorage
      ->loadByProperties($conditions);
    
    $tags = [];
    $tags[] = 'enrollment:' . $nid . '-' . $uid;
    $tags[] = 'event_content_list:entity:' . $uid;
    Cache::invalidateTags($tags);
    if ($enrollment = array_pop($enrollments)) {
      
      if ($enrollment->field_request_or_invite_status && (int) $enrollment->field_request_or_invite_status->value === EventEnrollmentInterface::INVITE_PENDING_REPLY) {
        
        $this
          ->messenger()
          ->deleteAll();
        
        $enrollment->field_enrollment_status->value = '1';
        $enrollment->field_request_or_invite_status->value = EventEnrollmentInterface::INVITE_ACCEPTED_AND_JOINED;
        
        if ($operation === 'decline') {
          
          $this
            ->messenger()
            ->deleteAll();
          $enrollment->field_enrollment_status->value = '0';
          $enrollment->field_request_or_invite_status->value = EventEnrollmentInterface::REQUEST_OR_INVITE_DECLINED;
        }
        $enrollment
          ->save();
      }
    }
  }
}