function BookAdminEditForm::validateForm

Same name and namespace in other branches
  1. 8.9.x core/modules/book/src/Form/BookAdminEditForm.php \Drupal\book\Form\BookAdminEditForm::validateForm()
  2. 10 core/modules/book/src/Form/BookAdminEditForm.php \Drupal\book\Form\BookAdminEditForm::validateForm()
  3. 11.x core/modules/book/src/Form/BookAdminEditForm.php \Drupal\book\Form\BookAdminEditForm::validateForm()

Overrides FormBase::validateForm

File

core/modules/book/src/Form/BookAdminEditForm.php, line 102

Class

BookAdminEditForm
Provides a form for administering a single book's hierarchy.

Namespace

Drupal\book\Form

Code

public function validateForm(array &$form, FormStateInterface $form_state) {
    if ($form_state->getValue('tree_hash') != $form_state->getValue('tree_current_hash')) {
        $form_state->setErrorByName('', $this->t('This book has been modified by another user, the changes could not be saved.'));
    }
}

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