gtm.module

<?php

/**
 * @file
 * Module gtm.module.
 */

/**
 * Implements hook_page_attachments().
 */
function gtm_page_attachments(array &$page) {
  $config = \Drupal::config('gtm.settings');
  $is_admin = \Drupal::service('router.admin_context')->isAdminRoute();

  $admin_pages = ($config->get('admin-pages') || !$is_admin);
  if (\Drupal::currentUser()->id() == 1 && $config->get('admin-disable')) {
    $admin_pages = FALSE;
  }
  if ($config->get('enable') && $config->get('google-tag') && $admin_pages) {
    $google_tag = $config->get('google-tag');
    $script = "(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
})(window,document,'script','dataLayer','{$google_tag}');\n";
    $page['#attached']['html_head'][] = [
      ['#tag' => 'script', '#value' => $script],
      'gtm',
    ];
  }
}

/**
 * Implements hook_page_top().
 */
function gtm_page_top(array &$page_top) {
  $config = \Drupal::config('gtm.settings');
  $is_admin = \Drupal::service('router.admin_context')->isAdminRoute();

  $admin_pages = ($config->get('admin-pages') || !$is_admin);
  if ($config->get('enable') && $config->get('google-tag') && $admin_pages) {
    $google_tag = $config->get('google-tag');
    $src = "https://www.googletagmanager.com/ns.html?id={$google_tag}";
    $page_top['gtm'] = [
      '#noscript' => TRUE,
      '#type' => 'html_tag',
      '#tag' => 'iframe',
      '#attributes' => [
        'src' => $src,
        'height' => 0,
        'width' => 0,
        'style' => 'display:none;visibility:hidden;'
      ],
    ];
  }
}