Reduce reliance on CMS module from Backend module

added backend 404 view, fixed return to backend URL in the access denied view on backend only instances

modules/backend/classes/BackendController.php

@@ -60,6 +60,21 @@ class BackendController extends ControllerBase
         self::extendableExtendCallback($callback);
     }
 
+    /**
+     * Pass unhandled URLs to the CMS Controller, if it exists
+     *
+     * @param string $url
+     * @return Response
+     */
+    protected function passToCmsController($url)
+    {
+        if (class_exists('\Cms\Classes\Controller')) {
+            return App::make('Cms\Classes\Controller')->run($url);
+        } else {
+            return Response::make(View::make('backend::404'), 404);
+        }
+    }
+
     /**
      * Finds and serves the requested backend controller.
      * If the controller cannot be found, returns the Cms page with the URL /404.
@@ -78,7 +93,7 @@ class BackendController extends ControllerBase
         if (!App::hasDatabase()) {
             return Config::get('app.debug', false)
                 ? Response::make(View::make('backend::no_database'), 200)
-                : App::make('Cms\Classes\Controller')->run($url);
+                : $this->passToCmsController($url);
         }
 
         /*
@@ -105,7 +120,7 @@ class BackendController extends ControllerBase
 
             $pluginCode = ucfirst($author) . '.' . ucfirst($plugin);
             if (PluginManager::instance()->isDisabled($pluginCode)) {
-                return App::make('Cms\Classes\Controller')->setStatusCode(404)->run('/404');
+                return Response::make(View::make('backend::404'), 404);
             }
 
             $controller = $params[2] ?? 'index';
@@ -124,7 +139,7 @@ class BackendController extends ControllerBase
         /*
          * Fall back on Cms controller
          */
-        return App::make('Cms\Classes\Controller')->run($url);
+        return $this->passToCmsController($url);
     }
 
     /**

modules/backend/classes/Controller.php

@@ -339,11 +339,15 @@ class Controller extends Extendable
         $result = null;
 
         if (!$this->actionExists($actionName)) {
+            if (Config::get('app.debug', false)) {
                 throw new SystemException(sprintf(
                     "Action %s is not found in the controller %s",
                     $actionName,
                     get_class($this)
                 ));
+            } else {
+                Response::make(View::make('backend::404'), 404);
+            }
         }
 
         // Execute the action
@@ -396,7 +400,7 @@ class Controller extends Extendable
                  * Validate the handler name
                  */
                 if (!preg_match('/^(?:\w+\:{2})?on[A-Z]{1}[\w+]*$/', $handler)) {
-                    throw new SystemException(Lang::get('cms::lang.ajax_handler.invalid_name', ['name'=>$handler]));
+                    throw new SystemException(Lang::get('backend::lang.ajax_handler.invalid_name', ['name'=>$handler]));
                 }
 
                 /*
@@ -407,7 +411,7 @@ class Controller extends Extendable
 
                     foreach ($partialList as $partial) {
                         if (!preg_match('/^(?!.*\/\/)[a-z0-9\_][a-z0-9\_\-\/]*$/i', $partial)) {
-                            throw new SystemException(Lang::get('cms::lang.partial.invalid_name', ['name'=>$partial]));
+                            throw new SystemException(Lang::get('backend::lang.partial.invalid_name', ['name'=>$partial]));
                         }
                     }
                 }
@@ -421,7 +425,7 @@ class Controller extends Extendable
                  * Execute the handler
                  */
                 if (!$result = $this->runAjaxHandler($handler)) {
-                    throw new ApplicationException(Lang::get('cms::lang.ajax_handler.not_found', ['name'=>$handler]));
+                    throw new ApplicationException(Lang::get('backend::lang.ajax_handler.not_found', ['name'=>$handler]));
                 }
 
                 /*

modules/backend/lang/en/lang.php

@@ -17,22 +17,32 @@ return [
     ],
     'page' => [
         'untitled' => 'Untitled',
+        '404' => [
+            'label'     => 'Page Not Found',
+            'help'      => "We searched and searched but the requested URL just couldn't be found. Perhaps you were looking for something else?",
+            'back_link' => 'Go back to the previous page',
+        ],
         'access_denied' => [
             'label' => 'Access denied',
             'help' => "You don't have the required permissions to view this page.",
-            'cms_link' => 'Return to the back-end'
+            'cms_link' => 'Return to the back-end',
         ],
         'no_database' => [
             'label' => 'Database missing',
             'help' => "A database is required to access the back-end. Check the database is configured and migrated before trying again.",
-            'cms_link' => 'Return to the homepage'
+            'cms_link' => 'Return to the homepage',
         ],
         'invalid_token' => [
-            'label' => 'Invalid security token'
+            'label' => 'Invalid security token',
-        ]
+        ],
     ],
     'partial' => [
-        'not_found_name' => "The partial ':name' is not found."
+        'not_found_name' => "The partial ':name' is not found.",
+        'invalid_name' => 'Invalid partial name: :name.',
+    ],
+    'ajax_handler' => [
+        'invalid_name' => 'Invalid AJAX handler name: :name.',
+        'not_found' => "AJAX handler ':name' was not found."
     ],
     'account' => [
         'signed_in_as' => 'Signed in as :full_name',

modules/backend/views/404.php

@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html lang="<?= App::getLocale() ?>">
+    <head>
+        <meta charset="utf-8">
+        <title><?= Lang::get('backend::lang.page.404.label') ?></title>
+        <link href="<?= Url::to('/modules/system/assets/css/styles.css') ?>" rel="stylesheet">
+    </head>
+    <body>
+        <div class="container">
+            <h1><i class="icon-chain-broken warning"></i> <?= Lang::get('backend::lang.page.404.label') ?></h1>
+            <br>
+            <p class="lead"><?= Lang::get('backend::lang.page.404.help') ?></p>
+            <p class="lead"><span style="font-family: monospace;"> <?= e(url()->current()); ?></span></p>
+            <a href="javascript:;" onclick="history.go(-1); return false;"><?= Lang::get('backend::lang.page.404.back_link') ?></a>
+            <br><br>
+            <a href="<?= Backend::url('') ?>"><?= Lang::get('backend::lang.page.access_denied.cms_link') ?></a>
+        </div>
+    </body>
+</html>

modules/backend/views/access_denied.php

@@ -9,7 +9,7 @@
         <div class="container">
             <h1><i class="icon-lock warning"></i> <?= Lang::get('backend::lang.page.access_denied.label') ?></h1>
             <p class="lead"><?= Lang::get('backend::lang.page.access_denied.help') ?></p>
-            <a href="<?= Backend::url('/') ?>"><?= Lang::get('backend::lang.page.access_denied.cms_link') ?></a>
+            <a href="<?= Backend::url('') ?>"><?= Lang::get('backend::lang.page.access_denied.cms_link') ?></a>
         </div>
     </body>
 </html>