Monitoring\Controller: provide $this->backend

Every monitoring controller needs $backend, so why declaring it over
and over again. Created "moduleInit" dummy function in our base action
controller to allow such implementations without polluting init().

library/Icinga/Web/Controller/ActionController.php

@@ -134,6 +134,7 @@ class ActionController extends Zend_Controller_Action
         if ($this->requiresConfig() === false) {
             if ($this->requiresLogin() === false) {
                 $this->view->tabs = new Tabs();
+                $this->moduleInit();
                 $this->init();
             } else {
                 $url = $this->getRequestUrl();
@@ -148,6 +149,10 @@ class ActionController extends Zend_Controller_Action
         }
     }
 
+    protected function moduleInit()
+    {
+    }
+
     protected function getWindowId()
     {
         if ($this->windowId === null) {

modules/monitoring/library/Monitoring/Controller.php

@@ -37,6 +37,13 @@ use Icinga\File\Csv;
  */
 class Controller extends ActionController
 {
+    /**
+     * The backend used for this controller
+     *
+     * @var Backend
+     */
+    protected $backend;
+
     /**
      * Compact layout name
      *
@@ -47,6 +54,11 @@ class Controller extends ActionController
      */
     protected $compactView;
 
+    protected function moduleInit()
+    {
+        $this->backend = Backend::createBackend($this->_getParam('backend'));
+    }
+
     protected function handleFormatRequest($query)
     {
         if ($this->compactView !== null && ($this->_getParam('view', false) === 'compact')) {