Issue #1987808 by h3rj4n, vijaycs85, Dave.Ingram, tim.plunkett: Convert...

Issue #1987808 by h3rj4n, vijaycs85, Dave.Ingram, tim.plunkett: Convert system_admin_compact_page() to a new style controller.

core/modules/system/lib/Drupal/system/Controller/SystemController.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\system\Controller\SystemController.
+ */
+
+namespace Drupal\system\Controller;
+
+use Drupal\Core\Controller\ControllerInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpFoundation\RedirectResponse;
+
+
+/**
+ * Returns responses for System routes.
+ */
+class SystemController implements ControllerInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static();
+  }
+
+  /**
+   * Sets whether the admin menu is in compact mode or not.
+   *
+   * @param string $mode
+   *   Valid values are 'on' and 'off'.
+   *
+   * @return \Symfony\Component\HttpFoundation\RedirectResponse
+   */
+  function compactPage($mode) {
+    user_cookie_save(array('admin_compact_mode' => ($mode == 'on')));
+    return new RedirectResponse(url('<front>', array('absolute' => TRUE)));
+  }
+
+}

core/modules/system/system.module

@@ -627,13 +627,6 @@ function system_menu() {
     'menu_name' => 'admin',
     'file' => 'system.admin.inc',
   );
-  $items['admin/compact'] = array(
-    'title' => 'Compact mode',
-    'page callback' => 'system_admin_compact_page',
-    'access arguments' => array('access administration pages'),
-    'type' => MENU_CALLBACK,
-    'file' => 'system.admin.inc',
-  );
   $items['admin/tasks'] = array(
     'title' => 'Tasks',
     'type' => MENU_DEFAULT_LOCAL_TASK,
@@ -2947,14 +2940,14 @@ function confirm_form($form, $question, $path, $description = NULL, $yes = NULL,
  * such as the configuration page and the permissions page.
  *
  * Whether the user is in compact mode is determined by a cookie, which is set
- * for the user by system_admin_compact_page().
+ * for the user by \Drupal\system\Controller\SystemController::compactPage().
  *
  * If the user does not have the cookie, the default value is given by the
  * system variable 'admin_compact_mode', which itself defaults to FALSE. This
  * does not have a user interface to set it: it is a hidden variable which can
  * be set in the settings.php file.
  *
- * @return
+ * @return bool
  *   TRUE when in compact mode, FALSE when in expanded mode.
  */
 function system_admin_compact_mode() {
@@ -2963,17 +2956,6 @@ function system_admin_compact_mode() {
   return isset($_COOKIE['Drupal_visitor_admin_compact_mode']) ? $_COOKIE['Drupal_visitor_admin_compact_mode'] : Drupal::config('system.site')->get('admin_compact_mode');
 }
 
-/**
- * Menu callback; Sets whether the admin menu is in compact mode or not.
- *
- * @param $mode
- *   Valid values are 'on' and 'off'.
- */
-function system_admin_compact_page($mode = 'off') {
-  user_cookie_save(array('admin_compact_mode' => ($mode == 'on')));
-  return new RedirectResponse(url('<front>', array('absolute' => TRUE)));
-}
-
 /**
  * Generate a list of tasks offered by a specified module.
  *

core/modules/system/system.routing.yml

@@ -10,6 +10,15 @@ system.cron:
     _controller: '\Drupal\system\CronController::run'
   requirements:
     _access_system_cron: 'TRUE'
+
+system_admin_compact_page:
+  pattern: '/admin/compact/{mode}'
+  defaults:
+    _controller: 'Drupal\system\Controller\SystemController::compactPage'
+    mode: 'off'
+  requirements:
+    _permission: 'access administration pages'
+
 system.machine_name_transliterate:
   pattern: '/machine_name/transliterate'
   defaults: