1<?php
2
3namespace Drupal\Core\Render\Element;
4
5use Drupal\Core\Form\FormStateInterface;
6use Drupal\Core\Render\Element;
7
8/**
9 * Provides an action button form element.
10 *
11 * When the button is pressed, the form will be submitted to Drupal, where it is
12 * validated and rebuilt. The submit handler is not invoked.
13 *
14 * Properties:
15 * - #limit_validation_errors: An array of form element keys that will block
16 *   form submission when validation for these elements or any child elements
17 *   fails. Specify an empty array to suppress all form validation errors.
18 * - #value: The text to be shown on the button.
19 *
20 *
21 * Usage Example:
22 * @code
23 * $form['actions']['preview'] = array(
24 *   '#type' => 'button',
25 *   '#value' => $this->t('Preview'),
26 * );
27 * @endcode
28 *
29 * @see \Drupal\Core\Render\Element\Submit
30 *
31 * @FormElement("button")
32 */
33class Button extends FormElement {
34
35  /**
36   * {@inheritdoc}
37   */
38  public function getInfo() {
39    $class = static::class;
40    return [
41      '#input' => TRUE,
42      '#name' => 'op',
43      '#is_button' => TRUE,
44      '#executes_submit_callback' => FALSE,
45      '#limit_validation_errors' => FALSE,
46      '#process' => [
47        [$class, 'processButton'],
48        [$class, 'processAjaxForm'],
49      ],
50      '#pre_render' => [
51        [$class, 'preRenderButton'],
52      ],
53      '#theme_wrappers' => ['input__submit'],
54    ];
55  }
56
57  /**
58   * Processes a form button element.
59   */
60  public static function processButton(&$element, FormStateInterface $form_state, &$complete_form) {
61    // If this is a button intentionally allowing incomplete form submission
62    // (e.g., a "Previous" or "Add another item" button), then also skip
63    // client-side validation.
64    if (isset($element['#limit_validation_errors']) && $element['#limit_validation_errors'] !== FALSE) {
65      $element['#attributes']['formnovalidate'] = 'formnovalidate';
66    }
67    return $element;
68  }
69
70  /**
71   * Prepares a #type 'button' render element for input.html.twig.
72   *
73   * @param array $element
74   *   An associative array containing the properties of the element.
75   *   Properties used: #attributes, #button_type, #name, #value. The
76   *   #button_type property accepts any value, though core themes have CSS that
77   *   styles the following button_types appropriately: 'primary', 'danger'.
78   *
79   * @return array
80   *   The $element with prepared variables ready for input.html.twig.
81   */
82  public static function preRenderButton($element) {
83    $element['#attributes']['type'] = 'submit';
84    Element::setAttributes($element, ['id', 'name', 'value']);
85
86    $element['#attributes']['class'][] = 'button';
87    if (!empty($element['#button_type'])) {
88      $element['#attributes']['class'][] = 'button--' . $element['#button_type'];
89    }
90    $element['#attributes']['class'][] = 'js-form-submit';
91    $element['#attributes']['class'][] = 'form-submit';
92
93    if (!empty($element['#attributes']['disabled'])) {
94      $element['#attributes']['class'][] = 'is-disabled';
95    }
96
97    return $element;
98  }
99
100}
101