edlp_d8/sites/all/modules/figli/edlp_mobile/edlp_mobile.module

<?php

/**
 * @file
 * Contains edlp_mobile.module.
 */

use Drupal\Core\Routing\RouteMatchInterface;
// use Drupal\domain\DomainStorage;
// use Drupal\domain\DomainElementManager;

/**
 * Implements hook_help().
 */
function edlp_mobile_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    // Main module help for the edlp_mobile module.
    case 'help.page.edlp_mobile':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('Handle some mobile behaviours') . '</p>';
      return $output;

    default:
  }
}


/**
* hook_entity_extra_field_info()
*/
// function edlp_mobile_entity_extra_field_info(){
//   $extra = [];
//   $extra['domain']['relations'] = [
//     'label' => t('Relations'),
//     'description' => 'Display enregistrement relations with other content types',
//     'weight' => 99,
//   ];
//   return $extra;
// }

// should be the right way
// function edlp_mobile_entity_field_storage_info(\Drupal\Core\Entity\EntityTypeInterface $entity_type) {
//   if ($entity_type->id() == 'domain') {
//     $definitions['device'] = \Drupal\Core\Field\BaseFieldDefinition::create('string')
//       ->setName('Device')
//       ->setLabel(t('Define a target device for this domain (mobile|desktop)'))
//       ->setTargetEntityTypeId($entity_type->id());
//     return $definitions;
//   }
// }

/**
 * Implements hook_page_attachments().
 * @param array $attachments
 */
function edlp_mobile_page_attachments(array &$attachments) {
  $is_mobile_domain = false;

  global $base_root;
  // dpm($base_root, '$base_root');

  $current_hostname = preg_replace('/http:\/\/|https:\/\//i', '', $base_root);
  // dpm($current_hostname, '$current_hostname');

  $domain_storage = \Drupal::entityTypeManager()->getStorage('domain');

  $mobile_domain = $domain_storage->load('m_encyclopediedelaparole_org');
  // dpm($mobile_domain, 'mobile_domain');

  $desktop_domain = $domain_storage->load('encyclopediedelaparole_org');
  // dpm($desktop_domain, 'desktop_domain');

  $current_domain = $domain_storage->loadByHostname($current_hostname);
  // dpm($current_domain, 'current_domain');

  if($current_domain){
    // we are in a main domain
    $is_mobile_domain = ($current_domain->id() == $mobile_domain->id());
    $mobile_url = $mobile_domain->getHostname();
    $desktop_url = $desktop_domain->getHostname();
  }else{
    // we are not in a main domain, so we look for an alias
    $domain_alias_storage = \Drupal::entityTypeManager()->getStorage('domain_alias');
    $alias = $domain_alias_storage->loadByHostname($current_hostname);
    // dpm($alias, '$alias');
    $domain_id = $alias->getDomainId();
    // dpm($domain_id, 'domain_id');
    $current_domain = $domain_storage->load($domain_id);
    // dpm($current_domain, 'current_domain');

    $env = $alias->getEnvironment();
    $env_aliases = $domain_alias_storage->loadByEnvironment($env);
    // dpm($env_aliases, '$env_aliases');
    // find out mibile alias and desktop alias
    // this is dirty
    // TODO: set target device as domain setting
    if ($domain_id == 'm_encyclopediedelaparole_org'){
      // current domain/alias is mobile
      $is_mobile_domain = true;
      $mobile_url = $alias->getPattern();
      // find desktop pattern
      // we assume that there is only two alias by env (mobile or desktop)
      foreach ($env_aliases as $env_alias_id => $env_alias) {
        if($env_alias_id != $alias->id()){
          // we found the desktop pattern
          $desktop_url = $env_alias->getPattern();
          break;
        }
      }
    }else{
      // current domain/alias is desktop
      $is_mobile_domain = false;
      $desktop_url = $alias->getPattern();
      // find mobile pattern
      // we assume that there is only two alias by env (mobile or desktop)
      foreach ($env_aliases as $env_alias_id => $env_alias) {
        if($env_alias_id != $alias->id()){
          // we found the mobile pattern
          $mobile_url = $env_alias->getPattern();
          break;
        }
      }
    }
  }

  $current_path = \Drupal::service('path.current')->getPath();
  $is_front = \Drupal::service('path.matcher')->isFrontPage();
  $current_language = \Drupal::languageManager()->getCurrentLanguage()->getId();

  // $config->set($domain_id . '.site_frontpage', $site_frontpage);

  // $mobile_home_path = "???";
  $mobile_home_path = \Drupal::config('domain_site_settings.domainconfigsettings')->get('m_encyclopediedelaparole_org.site_frontpage', FALSE);
  // $desktop_home_path = "???";
  $desktop_home_path = \Drupal::config('domain_site_settings.domainconfigsettings')->get('encyclopediedelaparole_org.site_frontpage', FALSE);

  // $redirect = false;
  $js_str = "var edlp_mobile = {\n
    current_url:'".$base_root."',\n
    current_path:'".$current_path."',\n
    is_front:".($is_front ? 'true':'false').",\n
    lang_code:'".$current_language."',\n
    is_mobile_domain:".($is_mobile_domain ? 'true':'false').",\n
    mobile_url:'".$mobile_url."',\n
    mobile_home_path:'".$mobile_home_path."',\n
    desktop_url:'".$desktop_url."',\n
    desktop_home_path:'".$desktop_home_path."',\n
  };";

  $attachments['#attached']['html_head'][] = [
    [
      '#type' => 'html_tag',
      '#tag' => 'script',
      '#value' => $js_str,
      '#weight' => -1000,
      '#group' => 'edlp'
    ],
    // A key, to make it possible to recognize this HTML  element when altering.
    'edlp_mobile',
  ];
}