MDL-56886 navigation: Allow local plugins to modify navigation via AJAX.

lib/navigationlib.php

@@ -1483,9 +1483,7 @@ class global_navigation extends navigation_node {
         }
 
         // Give the local plugins a chance to include some navigation if they want.
-        foreach (get_plugin_list_with_function('local', 'extend_navigation') as $function) {
-            $function($this);
-        }
+        $this->load_local_plugin_navigation();
 
         // Remove any empty root nodes
         foreach ($this->rootnodes as $node) {
@@ -1517,6 +1515,15 @@ class global_navigation extends navigation_node {
         return true;
     }
 
+    /**
+     * This function gives local plugins an opportunity to modify navigation.
+     */
+    protected function load_local_plugin_navigation() {
+        foreach (get_plugin_list_with_function('local', 'extend_navigation') as $function) {
+            $function($this);
+        }
+    }
+
     /**
      * Returns true if the current user is a parent of the user being currently viewed.
      *
@@ -3261,6 +3268,9 @@ class global_navigation_for_ajax extends global_navigation {
             $this->load_for_user(null, true);
         }
 
+        // Give the local plugins a chance to include some navigation if they want.
+        $this->load_local_plugin_navigation();
+
         $this->find_expandable($this->expandable);
         return $this->expandable;
     }