Implement ProblemMenuItemRenderer

refs # 4139

library/Icinga/Web/Menu.php

@@ -234,7 +234,8 @@ class Menu implements RecursiveIterator
 
             $section = $this->add(t('System'), array(
                 'icon'     => 'wrench',
-                'priority' => 200
+                'priority' => 200,
+                'renderer' => 'ProblemMenuItemRenderer'
             ));
             $section->add(t('Configuration'), array(
                 'url'           => 'config',
@@ -469,6 +470,26 @@ class Menu implements RecursiveIterator
         return $this->permission;
     }
 
+    /**
+     * Get parent menu
+     *
+     * @return \Icinga\Web\Menu
+     */
+    public function getParent()
+    {
+        return $this->parent;
+    }
+
+    /**
+     * Get submenus
+     *
+     * @return array
+     */
+    public function getSubMenus()
+    {
+        return $this->subMenus;
+    }
+
     /**
      * Set permission a user is required to have granted to display the menu item
      *

library/Icinga/Web/Menu/ProblemMenuItemRenderer.php

@@ -0,0 +1,64 @@
+<?php
+/* Icinga Web 2 | (c) 2013-2015 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Web\Menu;
+
+use Icinga\Web\Menu;
+
+class ProblemMenuItemRenderer extends MenuItemRenderer
+{
+    /**
+     * Set of summarized problems from submenus
+     *
+     * @var array
+     */
+    protected $summary = array();
+
+    /**
+     * Renders the html content of a single menu item and summarizes submenu problems
+     *
+     * @param Menu $menu
+     *
+     * @return string
+     */
+    public function render(Menu $menu)
+    {
+        if ($menu->getParent() !== null && $menu->hasSubMenus()) {
+            /** @var $submenu Menu */
+            foreach ($menu->getSubMenus() as $submenu) {
+                $renderer = $submenu->getRenderer();
+                if (method_exists($renderer, 'getSummary')) {
+                    if ($renderer->getSummary() !== null) {
+                        $this->summary[] =  $renderer->getSummary();
+                    }
+                }
+            }
+        }
+        return $this->getBadge() . $this->createLink($menu);
+    }
+
+    /**
+     * Get the problem badge
+     *
+     * @return string
+     */
+    protected function getBadge()
+    {
+        if (count($this->summary) > 0) {
+            $problems = 0;
+            $titles = array();
+
+            foreach ($this->summary as $summary) {
+                $problems += $summary['problems'];
+                $titles[] = $summary['title'];
+            }
+
+            return sprintf(
+                '<div title="%s" class="badge-container"><span class="badge badge-critical">%s</span></div>',
+                implode(', ', $titles),
+                $problems
+            );
+        }
+        return '';
+    }
+}