add getGadgetByPath() and refactor getElementByPath() so use it

jsonform.gadget.js

@@ -682,6 +682,9 @@
     .allowPublicAcquisition("checkValidity", function (arr) {
       return this.checkValidity(arr[0]);
     })
+    .declareMethod('getGadgetByPath', function (path) {
+      return this.props.form_gadget.getGadgetByPath(path || "/");
+    })
     .declareMethod('checkValidity', function (json_document) {
       // XXX need use local schema and local json document
       // in every subgadget to take into account user anyOf choice

jsonform/gadget_json_generated_form_child.js

@@ -1848,7 +1848,7 @@
         });
     })
 
-    .declareMethod('getElementByPath', function (data_path) {
+    .declareMethod('getGadgetByPath', function (data_path) {
       var g = this,
         array,
         path,
@@ -1878,7 +1878,7 @@
           next_data_path = "/" + next_data_path.slice(1).join("/");
           return g.getDeclaredGadget(array[idx].getAttribute('data-gadget-scope'))
             .push(function (gadget) {
-              return gadget.getElementByPath(next_data_path);
+              return gadget.getGadgetByPath(next_data_path);
             });
         }
 
@@ -1906,22 +1906,29 @@
         if (scope === false) {
           // gadget for this element absent
           // so find element in current gadget
-          return document.getElementById(
-            g.element.getAttribute("data-gadget-scope") + bingo + key + '/'
-          );
+          return {
+            gadget: g,
+            path: bingo + key + '/'
+          };
         }
         if (scope) {
           // get gadget by scope and use relative path for find element in gadget
           return g.getDeclaredGadget(scope)
             .push(function (gadget) {
-              return gadget.getElementByPath(next_data_path);
+              return gadget.getGadgetByPath(next_data_path);
             });
         }
       }
-      return RSVP.Queue()
-        .push(function () {
+      return {
+        gadget: g,
+        path: data_path
+      };
+    })
+    .declareMethod('getElementByPath', function (data_path) {
+      return this.getGadgetByPath(data_path)
+        .push(function (ret) {
           return document.getElementById(
-            g.element.getAttribute("data-gadget-scope") + data_path
+            ret.gadget.element.getAttribute("data-gadget-scope") + ret.path
           );
         });
     })