diff --git a/lib/accesslib.php b/lib/accesslib.php
index 29aac48d35720..81c5bca9cc8ed 100644
--- a/lib/accesslib.php
+++ b/lib/accesslib.php
@@ -4487,7 +4487,7 @@ function role_change_permission($roleid, $context, $capname, $permission) {
  * @property-read string $path path to context, starts with system context
  * @property-read dept $depth
  */
-abstract class context extends stdClass {
+abstract class context extends stdClass implements IteratorAggregate {
 
     /*
      * Google confirms that no other important framework is using "context" class,
@@ -4695,6 +4695,25 @@ public function __unset($name) {
         debugging('Can not unset context instance properties!');
     }
 
+    // ====== implementing method from interface IteratorAggregate ======
+
+    /**
+     * Create an iterator because magic vars can't be seen by 'foreach'.
+     *
+     * Now we can convert context object to array using convert_to_array(),
+     * and feed it properly to json_encode().
+     */
+    public function getIterator() {
+        $ret = array(
+            'id'           => $this->id,
+            'contextlevel' => $this->contextlevel,
+            'instanceid'   => $this->instanceid,
+            'path'         => $this->path,
+            'depth'        => $this->depth
+        );
+        return new ArrayIterator($ret);
+    }
+
     // ====== general context methods ======
 
     /**
diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 36c4c7606523b..c9016c160db42 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -10081,6 +10081,40 @@ function object_property_exists( $obj, $property ) {
     return array_key_exists( $property, $properties );
 }
 
+/**
+ * Converts an object into an associative array
+ *
+ * This function converts an object into an associative array by iterating
+ * over its public properties. Because this function uses the foreach
+ * construct, Iterators are respected. It works recursively on arrays of objects.
+ * Arrays and simple values are returned as is.
+ *
+ * If class has magic properties, it can implement IteratorAggregate
+ * and return all available properties in getIterator()
+ *
+ * @param mixed $var
+ * @return array
+ */
+function convert_to_array($var) {
+    $result = array();
+    $references = array();
+
+    // loop over elements/properties
+    foreach ($var as $key => $value) {
+        // recursively convert objects
+        if (is_object($value) || is_array($value)) {
+            // but prevent cycles
+            if (!in_array($value, $references)) {
+                $result[$key] = convert_to_array($value);
+                $references[] = $value;
+            }
+        } else {
+            // simple values are untouched
+            $result[$key] = $value;
+        }
+    }
+    return $result;
+}
 
 /**
  * Detect a custom script replacement in the data directory that will
diff --git a/lib/outputcomponents.php b/lib/outputcomponents.php
index f87c4ac26ca89..337452af0b466 100644
--- a/lib/outputcomponents.php
+++ b/lib/outputcomponents.php
@@ -1589,7 +1589,7 @@ class js_writer {
      */
     public static function function_call($function, array $arguments = null, $delay=0) {
         if ($arguments) {
-            $arguments = array_map('json_encode', $arguments);
+            $arguments = array_map('json_encode', convert_to_array($arguments));
             $arguments = implode(', ', $arguments);
         } else {
             $arguments = '';
@@ -1611,7 +1611,7 @@ public static function function_call($function, array $arguments = null, $delay=
      */
     public static function function_call_with_Y($function, array $extraarguments = null) {
         if ($extraarguments) {
-            $extraarguments = array_map('json_encode', $extraarguments);
+            $extraarguments = array_map('json_encode', convert_to_array($extraarguments));
             $arguments = 'Y, ' . implode(', ', $extraarguments);
         } else {
             $arguments = 'Y';
@@ -1630,7 +1630,7 @@ public static function function_call_with_Y($function, array $extraarguments = n
      */
     public static function object_init($var, $class, array $arguments = null, array $requirements = null, $delay=0) {
         if (is_array($arguments)) {
-            $arguments = array_map('json_encode', $arguments);
+            $arguments = array_map('json_encode', convert_to_array($arguments));
             $arguments = implode(', ', $arguments);
         }
 
diff --git a/lib/outputrequirementslib.php b/lib/outputrequirementslib.php
index f7a5e8afd593f..834604ca89f62 100644
--- a/lib/outputrequirementslib.php
+++ b/lib/outputrequirementslib.php
@@ -715,7 +715,7 @@ public function yui_module($modules, $function, array $arguments = null, $galler
             // Set Y's config.gallery to the version
             $jscode = 'Y.config.gallery='.json_encode($galleryversion).';';
         }
-        $jscode .= 'Y.use('.join(',', array_map('json_encode', $modules)).',function() {'.js_writer::function_call($function, $arguments).'});';
+        $jscode .= 'Y.use('.join(',', array_map('json_encode', convert_to_array($modules))).',function() {'.js_writer::function_call($function, $arguments).'});';
         if ($ondomready) {
             $jscode = "Y.on('domready', function() { $jscode });";
         }