custom_add_content-8.x-1.2/custom_add_content.module

<?php

/**
 * @file
 * Custom add content.
 */

use Drupal\Core\Form\FormStateInterface;
use Drupal\menu_link_content\Entity\MenuLinkContent;

/**
 * Implements hook_form_alter().
 *
 * When a new content type is created/edited/deleted we must update menu.
 * The rebuild action is automatically triggered by core on CT alter.
 */
function custom_add_content_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  switch ($form_id) {
    case 'node_type_add_form':
      $form['actions']['submit']['#submit'][] = 'custom_add_content_new_node_type_add';
      break;

    case 'node_type_delete_form':
      // Our handler goes first.
      array_unshift($form['actions']['submit']['#submit'], 'custom_add_content_new_node_type_rem');
      break;

    default:
      break;

  }
}

/**
 * Custom submit handler for node type adding. We add a menu item.
 */
function custom_add_content_new_node_type_add($form, FormStateInterface $form_state) {
  try {
    $values = $form_state->getValues();

    $item = MenuLinkContent::create([
      'title' => $values['name'],
      'link' => ['uri' => 'internal:/node/add/' . $values['type']],
      'menu_name' => 'custom-add-content-page',
      'expanded' => TRUE,
    ]);
    $item->save();
  }
  catch (Exception $e) {
    \Drupal::logger('custom_add_content')->notice($e->getMessage());
  }
}

/**
 * Custom submit handler for node type remove.
 *
 * We remove the corresponding menu item.
 */
function custom_add_content_new_node_type_rem($form, FormStateInterface $form_state) {
  try {
    $path = \Drupal::service('path.current')->getPath();
    $parts = explode('/', $path);
    $ct_machine_name = $parts[5];

    if (!empty($ct_machine_name)) {
      $menu = Drupal::entityTypeManager()
        ->getStorage('menu_link_content')
        ->loadByProperties(['link__uri' => 'internal:/node/add/' . $ct_machine_name]);
      if (!empty($menu)) {
        $first = array_values($menu)[0];
        $first->delete();
      }
    }
  }
  catch (Exception $e) {
    \Drupal::logger('custom_add_content')->notice($e->getMessage());
  }
}

/**
 * Implements hook_theme().
 *
 * Custom twig template.
 */
function custom_add_content_theme() {
  return [
    'custom_add_content_page_add' => [
      'variables' => ['menu_name' => NULL, 'items' => NULL],
    ],
  ];
}