form

/**
* Implements hook_entity_type_alter().
*/
function mymodule_entity_type_alter(array &$entity_types) {
 if (isset($entity_types['privatemsg_message'])) {
   $entity_types['privatemsg_message']->setFormClass('add'

$node = $this->entityTypeManager()->getStorage('node')->load($nid);
if ($node) {
 $form = $this->entityTypeManager()->getFormObject('node', 'default')->setEntity($node);
 return $this->formBuilder()->getForm($form);
}

$node = $this->entityTypeManager()->getStorage('node')->create(['type' => 'bio']);
return $this->entityFormBuilder()->getForm($node);

/**
* Implements hook_form_FORM_ID_alter().
*/
function MYMODULE_form_user_form_alter(&$form, FormStateInterface $form_state) {
 if ($form_state->getFormObject()->getOperation() === 'default') {
   // some code...
 }
}

$form['#attached']['library'][] = 'photoswipe/photoswipe.init';
$template = ['#theme' => 'photoswipe_container'];
$form['#attached']['drupalSettings']['photoswipe']['container'] = \Drupal::service('renderer')->renderP

<form{{ attributes }}>
 <div class="wrapper d-flex">
   <div class="left">
     

/**
* Implements hook_form_FORM_ID_alter().
*/
function MYMODULE_form_node_blog_edit_form_alter(&$form, FormStateInterface $form_state, $form_id) {
 $fields = ['field_images', 'field_video'];
 foreach ($fields as $field_name) {
   $elements = $for

/**
 * {@inheritdoc}
 */
public function buildForm(array $form, FormStateInterface $form_state) {
 $form['#attached'] = [
   'library' => ['my_module/my_library'],
 ];
 return $form;
}

use Drupal\Core\Render\RendererInterface;

/**
 * Defines an interface for turning a render array into a string.
 */
protected RendererInterface $renderer;

/**
 * The form constructor.
 *
 * @param \Drupal\Core\Render\RendererInterface $renderer
 *   The renderer.
 */

$this->messenger()->addMessage($this->t('System tag can be added only automatically'), 'error', TRUE);
$message = [
 '#theme' => 'status_messages',
 '#message_list' => $this->messenger()->deleteAll(),
];
$messages = \Drupal::service(