drupal 8 form alter submit handler

gistfile1.txt

function mymodule_form_node_form_alter(&$form, FormStateInterface $form_state) {
  // For entity builders.
  kint($form['#form_id']);
  if($form['#form_id'] == 'node_page_edit_form') {
    foreach (array_keys($form['actions']) as $action) {
      if ($action != 'preview' && isset($form['actions'][$action]['#type']) && $form['actions'][$action]['#type'] === 'submit') {
        $form['actions'][$action]['#submit'][] = 'mymodule_node_form_submit';
      }
    }
  }



}

function mymodule_node_form_submit($form, FormStateInterface $form_state) {
  $node = $form_state->getFormObject()->getEntity();
  \Drupal::logger('mfdev')->notice('Got here ') ;

  drupal_set_message("I was here");


  // mymodule_do_something($node);
}