Hook for adding values to add node page

Question

I'm searching for a hook in Drupal 8 API for adding values to a add content form. What hook can I use to alter values from /node/add/movies_movie page?

Answer 1

Inside your module, there is a [your-module].module file where you can write hook_form_alter().

/**
 * Implements hook_form_alter().
 */
 function module_name_form_alter(&$form, FormStateInterface $form_state, $form_id) {
   if ($form_id == 'node_movies_movie_form') {
     // Your code goes here.
     ...
     ...
   }
 }

Answer 2

Think you are looking for the form alter hook here: https://api.drupal.org/api/drupal/core%21lib%21Drupal%21Core%21Form%21form.api.php/function/hook_form_alter/8.2.x