split renderForm() and rerender()

jsonform/gadget_json_generated_form_child.js

@@ -1952,23 +1952,13 @@
     .declareMethod('renderForm', function (options) {
       var g = this,
         property_name = g.element.getAttribute('data-json-property-name'),
-        schema = options.schema_arr !== undefined && options.schema_arr[0].schema,
-        root;
+        schema = options.schema_arr !== undefined && options.schema_arr[0].schema;
       g.props.changed = false;
       g.props.saveOrigValue = options.saveOrigValue;
-      g.props.inputs = [];
-      g.props.add_buttons = [];
-      g.props.add_custom_data = {};
-      g.props.arrays = {};
-      g.props.objects = {};
       g.props.path = options.path; // self gadget scope
       if (!property_name || !options.display_label) {
         property_name = "";
       }
-      root = g.element.querySelector('[data-json-path="/"]');
-      if (!root) {
-        root = g.element;
-      }
       if (options.delete_button === undefined) {
         if (options.top) {
           options.delete_button = false;
@@ -1982,23 +1972,41 @@
       // used for empty document generation
       g.props.type = (schema && typeof schema.type === "string" && schema.type) ||
                      options.type || getDocumentType(options.document);
-      while (root.firstChild) {
-        root.removeChild(root.firstChild);
-      }
       if (checkSchemaIsMetaSchema(schema)) {
         g.props.updatePropertySelectors = true;
         g.props.current_document = options.document;
       }
-      return render_field(g, property_name, "", options.schema_arr,
-        options.document, root,
-        {
-          type: options.type,
-          selected_schema: options.selected_schema,
-          required: options.required,
-          delete_button: options.delete_button,
-          top: options.top
-        })
+      g.props.property_name = property_name;
+      g.props.schema_arr = options.schema_arr;
+      g.props.render_opt = {
+        type: options.type,
+        selected_schema: options.selected_schema,
+        required: options.required,
+        delete_button: options.delete_button,
+        top: options.top
+      };
+      return g.rerender(options.document);
+    })
+
+    .declareMethod('rerender', function (document) {
+      var g = this,
+        for_delete,
+        root = g.element.querySelector('[data-json-path="/"]');
+      g.props.inputs = [];
+      g.props.add_buttons = [];
+      g.props.add_custom_data = {};
+      g.props.arrays = {};
+      g.props.objects = {};
+      if (!root) {
+        root = g.element;
+      }
+      for_delete = Array.from(root.childNodes);
+      return render_field(g, g.props.property_name, "", g.props.schema_arr,
+        document, root, g.props.render_opt)
         .push(function () {
+          for (var i = 0; i < for_delete.length; i += 1) {
+            root.removeChild(for_delete[i]);
+          }
           return g.element;
         });
     })