(menu) add filter for menu items, creating space for https://github.com/opnsense/core/issues/508

Using this version, it will already be possible to "delete" (sub)menus from inherited structures, using the visibility="delete" tag on an item.

(cherry picked from commit d5378085)

src/opnsense/mvc/app/models/OPNsense/Base/Menu/MenuItem.php

@@ -340,7 +340,7 @@ class MenuItem
     public function toggleSelected($url)
     {
         $this->selected = false ;
-        foreach ($this->children as $nodeId => $node) {
+        foreach ($this->getFilteredChildren() as $nodeId => $node) {
             $node->toggleSelected($url);
             if ($node->getUrl() != "") {
                 $match =  str_replace(array(".", "*","?"), array("\.", ".*","\?"), $node->getUrl());
@@ -351,6 +351,23 @@ class MenuItem
         }
     }
 
+    /**
+     * Menu items are pluggable and can override already existing sections.
+     * This function filters the available child items and only return the still existing ones.
+     * @return array filtered set of children
+     */
+    private function getFilteredChildren()
+    {
+        $result = array();
+        foreach ($this->children as $key => $node) {
+            if ($node->getVisibility() != 'delete') {
+                $result[$key] = $node;
+            }
+        }
+        ksort($result);
+        return $result;
+    }
+
     /**
      * Recursive method to retrieve a simple ordered structure of all menu items
      * @return array named array containing menu items as simple objects to keep the api cleaner for our templates
@@ -369,8 +386,7 @@ class MenuItem
         }
 
         // sort by order/id and map getters to array items
-        ksort($this->children);
-        foreach ($this->children as $key => $node) {
+        foreach ($this->getFilteredChildren() as $key => $node) {
             $result[$node->id] = new \stdClass();
             foreach ($properties as $methodName => $propName) {
                 $result[$node->id]->{$propName} = $node->$methodName();
@@ -387,7 +403,7 @@ class MenuItem
      */
     public function findNodeById($id)
     {
-        foreach ($this->children as $key => $node) {
+        foreach ($this->getFilteredChildren() as $key => $node) {
             if (strtolower($node->getId()) == strtolower($id)) {
                 return $node ;
             }