respondjs-8.x-1.x-dev/respondjs.module

<?php

/**
 * @file
 * Contains respondjs.module.
 */

use Drupal\Core\Routing\RouteMatchInterface;

/**
 * Implements hook_help().
 */
function respondjs_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    case 'help.page.respondjs':
      $output = '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('It allows browsers without native MQ support to have a rudimentary ability to process CSS wrapped in max- and min-width MQs.') . '</p>';

      return $output;
  }
}

/**
 * Implements hook_page_top().
 */
function respondjs_page_top(&$page_top) {
  $page_top['#attached'] = [
    'library' => [
      'respondjs/respondjs',
    ],
  ];

  $config = \Drupal::configFactory()->getEditable('respondjs.settings');
  if (empty($config->get('warn'))) {
    $preprocessed = \Drupal::config('system.performance')->get('css.preprocess');
    $route = \Drupal::routeMatch()->getRouteObject();
    $is_admin = \Drupal::service('router.admin_context')->isAdminRoute($route);
    if ($preprocessed === FALSE && $is_admin === TRUE) {
      \Drupal::messenger()->addError(t('The Respond.js module is enabled, but CSS aggregation is disabled. The script cannot function until <a href="/admin/config/development/performance">CSS aggregation is enabled</a>.'), 'error');
    }
  }
}