Force or Forbid installer depending on app state

index.php

@@ -17,4 +17,4 @@ Yii::setAlias('@webroot', __DIR__);
 Yii::setAlias('@app', __DIR__ . DIRECTORY_SEPARATOR . 'protected');
 Yii::setAlias('@humhub', '@app/humhub');
 
-(new yii\web\Application($config))->run();
+(new humhub\components\Application($config))->run();

protected/humhub/components/Application.php

@@ -0,0 +1,35 @@
+<?php
+
+/**
+ * @link https://www.humhub.org/
+ * @copyright Copyright (c) 2015 HumHub GmbH & Co. KG
+ * @license https://www.humhub.com/licences
+ */
+
+namespace humhub\components;
+
+use Yii;
+
+/**
+ * Base WebApplication
+ *
+ * @author luke
+ */
+class Application extends \yii\web\Application
+{
+
+    public function beforeAction($action)
+    {
+
+        /**
+         * Check if it's already installed - if not force controller module
+         */
+        if (!$this->params['installed'] && $this->controller->module != null && $this->controller->module->id != 'installer') {
+            $this->controller->redirect(\yii\helpers\Url::to(['/installer/index']));
+            return false;
+        }
+
+        return parent::beforeAction($action);
+    }
+
+}

protected/humhub/core/installer/Module.php

@@ -38,6 +38,15 @@ class Module extends \yii\base\Module
         $this->layout = '@humhub/core/installer/views/layouts/main.php';
     }
 
+    public function beforeAction($action)
+    {
+        if (Yii::$app->params['installed']) {
+            throw new \yii\web\HttpException(500, 'HumHub is already installed!');
+        }
+
+        return parent::beforeAction($action);
+    }
+
     /**
      * Checks if database connections works
      *