1<?php
2
3namespace Drupal\form_test;
4
5use Drupal\Core\Form\FormStateInterface;
6
7/**
8 * Simple class for testing methods as Form API callbacks.
9 */
10class Callbacks {
11
12  /**
13   * Form element validation handler for 'name' in form_test_validate_form().
14   */
15  public function validateName(&$element, FormStateInterface $form_state) {
16    $triggered = FALSE;
17    if ($form_state->getValue('name') == 'element_validate') {
18      // Alter the form element.
19      $element['#value'] = '#value changed by #element_validate';
20      // Alter the submitted value in $form_state.
21      $form_state->setValueForElement($element, 'value changed by setValueForElement() in #element_validate');
22
23      $triggered = TRUE;
24    }
25    if ($form_state->getValue('name') == 'element_validate_access') {
26      $form_state->set('form_test_name', $form_state->getValue('name'));
27      // Alter the form element.
28      $element['#access'] = FALSE;
29
30      $triggered = TRUE;
31    }
32    elseif ($form_state->has('form_test_name')) {
33      // To simplify this test, just take over the element's value into $form_state.
34      $form_state->setValueForElement($element, $form_state->get('form_test_name'));
35
36      $triggered = TRUE;
37    }
38
39    if ($triggered) {
40      // Output the element's value from $form_state.
41      \Drupal::messenger()->addStatus(t('@label value: @value', ['@label' => $element['#title'], '@value' => $form_state->getValue('name')]));
42
43      // Trigger a form validation error to see our changes.
44      $form_state->setErrorByName('');
45    }
46  }
47
48}
49