class BuildDemo

Same name and namespace in other branches
  1. 4.0.x modules/form_api_example/src/Form/BuildDemo.php \Drupal\form_api_example\Form\BuildDemo

Implements the build demo form controller.

This example uses the Messenger service to demonstrate the order of controller method invocations by the form api.

Hierarchy

Expanded class hierarchy of BuildDemo

See also

\Drupal\Core\Form\FormBase

\Drupal\Core\Form\ConfigFormBase

1 string reference to 'BuildDemo'
form_api_example.routing.yml in modules/form_api_example/form_api_example.routing.yml
modules/form_api_example/form_api_example.routing.yml

File

modules/form_api_example/src/Form/BuildDemo.php, line 17

Namespace

Drupal\form_api_example\Form
View source
class BuildDemo extends FormBase {
  
  /**
   * Counter keeping track of the sequence of method invocation.
   *
   * @var int
   */
  protected static $sequenceCounter = 0;
  
  /**
   * {@inheritdoc}
   */
  public function __construct() {
    $this->displayMethodInvocation('__construct');
  }
  
  /**
   * Update form processing information.
   *
   * Display the method being called and it's sequence in the form
   * processing.
   *
   * @param string $method_name
   *   The method being invoked.
   */
  private function displayMethodInvocation($method_name) {
    self::$sequenceCounter++;
    $this->messenger()
      ->addMessage(self::$sequenceCounter . ". {$method_name}");
  }
  
  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state) {
    $form['description'] = [
      '#type' => 'item',
      '#markup' => $this->t('Demonstrates how submit, rebuild, form-rebuild and #ajax submit work.'),
    ];
    // Simple checkbox for ajax orders.
    $form['change'] = [
      '#type' => 'checkbox',
      '#title' => $this->t('Change Me'),
      '#ajax' => [
        'callback' => '::ajaxSubmit',
        'wrapper' => 'message-wrapper',
      ],
    ];
    $form['actions'] = [
      '#type' => 'actions',
    ];
    // Add a submit button that handles the submission of the form.
    $form['actions']['submit'] = [
      '#type' => 'submit',
      '#value' => 'Submit',
    ];
    // Add button handlers.
    $form['actions']['button'] = [
      '#type' => 'button',
      '#value' => 'Rebuild',
    ];
    $form['actions']['rebuild'] = [
      '#type' => 'submit',
      '#value' => 'Submit Rebuild',
      '#submit' => [
        '::rebuildFormSubmit',
      ],
    ];
    $form['actions']['ajaxsubmit'] = [
      '#type' => 'submit',
      '#value' => 'Ajax Submit',
      '#ajax' => [
        'callback' => '::ajaxSubmit',
        'wrapper' => 'message-wrapper',
      ],
    ];
    $form['messages'] = [
      '#type' => 'container',
      '#attributes' => [
        'id' => 'message-wrapper',
      ],
    ];
    return $form;
  }
  
  /**
   * {@inheritdoc}
   */
  public function getFormId() {
    $this->displayMethodInvocation('getFormId');
    return 'form_api_example_build_form';
  }
  
  /**
   * {@inheritdoc}
   */
  public function validateForm(array &$form, FormStateInterface $form_state) {
    $this->displayMethodInvocation('validateForm');
  }
  
  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    $this->displayMethodInvocation('submitForm');
  }
  
  /**
   * Implements ajax submit callback.
   *
   * @param array $form
   *   Form render array.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   Current state of the form.
   */
  public function ajaxSubmit(array &$form, FormStateInterface $form_state) {
    $this->displayMethodInvocation('ajaxSubmit');
    $form['messages']['status'] = [
      '#type' => 'status_messages',
    ];
    return $form['messages'];
  }
  
  /**
   * Implements submit callback for Rebuild button.
   *
   * @param array $form
   *   Form render array.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   Current state of the form.
   */
  public function rebuildFormSubmit(array &$form, FormStateInterface $form_state) {
    $this->displayMethodInvocation('rebuildFormSubmit');
    $form_state->setRebuild(TRUE);
  }

}

Members

Title Sort descending Modifiers Object type Summary
BuildDemo::$sequenceCounter protected static property Counter keeping track of the sequence of method invocation.
BuildDemo::ajaxSubmit public function Implements ajax submit callback.
BuildDemo::buildForm public function
BuildDemo::displayMethodInvocation private function Update form processing information.
BuildDemo::getFormId public function
BuildDemo::rebuildFormSubmit public function Implements submit callback for Rebuild button.
BuildDemo::submitForm public function
BuildDemo::validateForm public function
BuildDemo::__construct public function