class SimpleFormBlock

Provides a 'Example: Display a form' block.

This example demonstrates the use of the form_builder service, an instance of \Drupal\Core\Form\FormBuilder, in order to retrieve and display a form.

Plugin annotation


@Block(
  id = "form_api_example_simple_form_block",
  admin_label = @Translation("Example: Display a form")
)

Hierarchy

class \Drupal\form_api_example\Plugin\Block\SimpleFormBlock implements \Drupal\Core\Plugin\ContainerFactoryPluginInterface extends \Drupal\Core\Block\BlockBase

Expanded class hierarchy of SimpleFormBlock

File

View on git.drupalcode.org

modules/form_api_example/src/Plugin/Block/SimpleFormBlock.php, line 23

Namespace

Drupal\form_api_example\Plugin\Block

View source

class SimpleFormBlock extends BlockBase implements ContainerFactoryPluginInterface {
  
  /**
   * Form builder service.
   *
   * @var \Drupal\Core\Form\FormBuilderInterface
   */
  protected $formBuilder;
  
  /**
   * {@inheritdoc}
   */
  public function __construct(array $configuration, $plugin_id, $plugin_definition, FormBuilderInterface $form_builder) {
    parent::__construct($configuration, $plugin_id, $plugin_definition);
    $this->formBuilder = $form_builder;
  }
  
  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    return new static($configuration, $plugin_id, $plugin_definition, $container->get('form_builder'));
  }
  
  /**
   * {@inheritdoc}
   */
  public function build() {
    $output = [
      'description' => [
        '#markup' => $this->t('Using form provided by @classname', [
          '@classname' => SimpleForm::class,
        ]),
      ],
    ];
    // Use the form builder service to retrieve a form by providing the full
    // name of the class that implements the form you want to display. getForm()
    // will return a render array representing the form that can be used
    // anywhere render arrays are used.
    //
    // In this case the build() method of a block plugin is expected to return
    // a render array so we add the form to the existing output and return it.
    $output['form'] = $this->formBuilder
      ->getForm(SimpleForm::class);
    return $output;
  }

}

Members

Title Sort descending	Modifiers	Object type	Summary
SimpleFormBlock::$formBuilder	protected	property	Form builder service.
SimpleFormBlock::build	public	function
SimpleFormBlock::create	public static	function
SimpleFormBlock::__construct	public	function

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