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class Button in Drupal 8

Same name and namespace in other branches
  1. 9 core/lib/Drupal/Core/Render/Element/Button.php \Drupal\Core\Render\Element\Button

Provides an action button form element.

When the button is pressed, the form will be submitted to Drupal, where it is validated and rebuilt. The submit handler is not invoked.

Properties:

  • #limit_validation_errors: An array of form element keys that will block form submission when validation for these elements or any child elements fails. Specify an empty array to suppress all form validation errors.
  • #value: The text to be shown on the button.

Usage Example:

$form['actions']['preview'] = array(
  '#type' => 'button',
  '#value' => $this
    ->t('Preview'),
);

Plugin annotation

@FormElement("button");

Hierarchy

Expanded class hierarchy of Button

See also

\Drupal\Core\Render\Element\Submit

2 string references to 'Button'
ckeditor.schema.yml in core/modules/ckeditor/config/schema/ckeditor.schema.yml
core/modules/ckeditor/config/schema/ckeditor.schema.yml
FormTestDisabledElementsForm::buildForm in core/modules/system/tests/modules/form_test/src/Form/FormTestDisabledElementsForm.php
Form constructor.
9 #type uses of Button
AjaxTestImageEffect::buildConfigurationForm in core/modules/image/tests/modules/image_module_test/src/Plugin/ImageEffect/AjaxTestImageEffect.php
Form constructor.
ContentModerationConfigureEntityTypesForm::buildForm in core/modules/content_moderation/src/Form/ContentModerationConfigureEntityTypesForm.php
Form constructor.
FormElementsRenderTest::testDrupalRenderFormElements in core/modules/system/tests/src/Kernel/Common/FormElementsRenderTest.php
Tests rendering form elements without passing through \Drupal::formBuilder()->doBuildForm().
FormTestButtonClassForm::buildForm in core/modules/system/tests/modules/form_test/src/Form/FormTestButtonClassForm.php
Form constructor.
FormTestDisabledElementsForm::buildForm in core/modules/system/tests/modules/form_test/src/Form/FormTestDisabledElementsForm.php
Form constructor.

... See full list

File

core/lib/Drupal/Core/Render/Element/Button.php, line 33

Namespace

Drupal\Core\Render\Element
View source
class Button extends FormElement {

  /**
   * {@inheritdoc}
   */
  public function getInfo() {
    $class = get_class($this);
    return [
      '#input' => TRUE,
      '#name' => 'op',
      '#is_button' => TRUE,
      '#executes_submit_callback' => FALSE,
      '#limit_validation_errors' => FALSE,
      '#process' => [
        [
          $class,
          'processButton',
        ],
        [
          $class,
          'processAjaxForm',
        ],
      ],
      '#pre_render' => [
        [
          $class,
          'preRenderButton',
        ],
      ],
      '#theme_wrappers' => [
        'input__submit',
      ],
    ];
  }

  /**
   * Processes a form button element.
   */
  public static function processButton(&$element, FormStateInterface $form_state, &$complete_form) {

    // If this is a button intentionally allowing incomplete form submission
    // (e.g., a "Previous" or "Add another item" button), then also skip
    // client-side validation.
    if (isset($element['#limit_validation_errors']) && $element['#limit_validation_errors'] !== FALSE) {
      $element['#attributes']['formnovalidate'] = 'formnovalidate';
    }
    return $element;
  }

  /**
   * Prepares a #type 'button' render element for input.html.twig.
   *
   * @param array $element
   *   An associative array containing the properties of the element.
   *   Properties used: #attributes, #button_type, #name, #value. The
   *   #button_type property accepts any value, though core themes have CSS that
   *   styles the following button_types appropriately: 'primary', 'danger'.
   *
   * @return array
   *   The $element with prepared variables ready for input.html.twig.
   */
  public static function preRenderButton($element) {
    $element['#attributes']['type'] = 'submit';
    Element::setAttributes($element, [
      'id',
      'name',
      'value',
    ]);
    $element['#attributes']['class'][] = 'button';
    if (!empty($element['#button_type'])) {
      $element['#attributes']['class'][] = 'button--' . $element['#button_type'];
    }
    $element['#attributes']['class'][] = 'js-form-submit';
    $element['#attributes']['class'][] = 'form-submit';
    if (!empty($element['#attributes']['disabled'])) {
      $element['#attributes']['class'][] = 'is-disabled';
    }
    return $element;
  }

}

Members

Namesort descending Modifiers Type Description Overrides
Button::getInfo public function Returns the element properties for this element. Overrides ElementInterface::getInfo 1
Button::preRenderButton public static function Prepares a #type 'button' render element for input.html.twig. 1
Button::processButton public static function Processes a form button element.
DependencySerializationTrait::$_entityStorages protected property An array of entity type IDs keyed by the property name of their storages.
DependencySerializationTrait::$_serviceIds protected property An array of service IDs keyed by property name used for serialization.
DependencySerializationTrait::__sleep public function 1
DependencySerializationTrait::__wakeup public function 2
FormElement::processAutocomplete public static function Adds autocomplete functionality to elements.
FormElement::processPattern public static function #process callback for #pattern form element property.
FormElement::validatePattern public static function #element_validate callback for #pattern form element property.
FormElement::valueCallback public static function Determines how user input is mapped to an element's #value property. Overrides FormElementInterface::valueCallback 15
MessengerTrait::$messenger protected property The messenger. 29
MessengerTrait::messenger public function Gets the messenger. 29
MessengerTrait::setMessenger public function Sets the messenger.
PluginBase::$configuration protected property Configuration information passed into the plugin. 1
PluginBase::$pluginDefinition protected property The plugin implementation definition. 1
PluginBase::$pluginId protected property The plugin_id.
PluginBase::DERIVATIVE_SEPARATOR constant A string which is used to separate base plugin IDs from the derivative ID.
PluginBase::getBaseId public function Gets the base_plugin_id of the plugin instance. Overrides DerivativeInspectionInterface::getBaseId
PluginBase::getDerivativeId public function Gets the derivative_id of the plugin instance. Overrides DerivativeInspectionInterface::getDerivativeId
PluginBase::getPluginDefinition public function Gets the definition of the plugin implementation. Overrides PluginInspectionInterface::getPluginDefinition 3
PluginBase::getPluginId public function Gets the plugin_id of the plugin instance. Overrides PluginInspectionInterface::getPluginId
PluginBase::isConfigurable public function Determines if the plugin is configurable.
PluginBase::__construct public function Constructs a \Drupal\Component\Plugin\PluginBase object. 92
RenderElement::preRenderAjaxForm public static function Adds Ajax information about an element to communicate with JavaScript.
RenderElement::preRenderGroup public static function Adds members of this group as actual elements for rendering.
RenderElement::processAjaxForm public static function Form element processing handler for the #ajax form property. 1
RenderElement::processGroup public static function Arranges elements into groups.
RenderElement::setAttributes public static function Sets a form element's class attribute. Overrides ElementInterface::setAttributes
StringTranslationTrait::$stringTranslation protected property The string translation service. 1
StringTranslationTrait::formatPlural protected function Formats a string containing a count of items.
StringTranslationTrait::getNumberOfPlurals protected function Returns the number of plurals supported by a given language.
StringTranslationTrait::getStringTranslation protected function Gets the string translation service.
StringTranslationTrait::setStringTranslation public function Sets the string translation service to use. 2
StringTranslationTrait::t protected function Translates a string to the current language or to a given language.