Merge pull request #458 from plotly/adjust-dereferencing

Remove key and keysrc when no dataSources

Author: VeraZab

src/lib/dereference.js

@@ -2,20 +2,29 @@ import walkObject from './walkObject';
 
 const SRC_ATTR_PATTERN = /src$/;
 
-export default function dereference(container, dataSources) {
+export default function dereference(
+  container,
+  dataSources,
+  config = {deleteKeys: false}
+) {
   const replacer = (key, parent) => {
     if (!SRC_ATTR_PATTERN.test(key)) {
       return;
     }
 
     const srcRef = parent[key];
     const data = dataSources[srcRef];
+    const dataKey = key.replace(SRC_ATTR_PATTERN, '');
+
+    if (config.deleteKeys && !(srcRef in dataSources)) {
+      delete parent[dataKey];
+      return;
+    }
 
     if (!Array.isArray(data)) {
       return;
     }
 
-    const dataKey = key.replace(SRC_ATTR_PATTERN, '');
     parent[dataKey] = data;
   };