use parent scope as prefix so we can filter all sub_gadgets target gadget

jsonform/gadget_json_generated_form_child.js

@@ -278,6 +278,14 @@
     return input;
   }
 
+  function generateUid(g) {
+    // generate scope use parent scope as prefix so
+    // we can filter all sub_gadgets target gadget
+    // XXX size?
+    var z = g.element.getAttribute('data-gadget-scope');
+    return z + '_' + Math.random().toString(36).substr(2, 5);
+  }
+
   function addSubForm(options) {
     var input_element = options.element,
       g = options.gadget,
@@ -285,7 +293,7 @@
       parent_path,
       scope;
 
-    scope = "j" + Math.random().toString(36).substr(2, 9);
+    scope = generateUid(g);
     parent_path = options.parent_path;
     if (options.parent_type !== "array") {
       property_name = options.property_name;