Only load ES6 module loader polyfill if needed

Safari and Chrome now have native support for modules, so we need to make sure we only load our polyfill when actually needed.

diff --git a/vnc_lite.html b/vnc_lite.html
index 68faf42c87bea3d811205380a020f92d8b03abe6..729aabb1ec9bcab7da95c8228b8f92e097205d64 100644 (file)
--- a/vnc_lite.html
+++ b/vnc_lite.html
@@ -60,7 +60,20 @@
 
     <!-- promise polyfills promises for IE11 -->
     <script src="vendor/promise.js"></script>
-    <script src="vendor/browser-es-module-loader/dist/browser-es-module-loader.js"></script>
+    <!-- ES2015/ES6 modules polyfill -->
+    <script type="module">
+        window._noVNC_has_module_support = true;
+    </script>
+    <script>
+        window.addEventListener("load", function() {
+            if (window._noVNC_has_module_support) return;
+            var loader = document.createElement("script");
+            loader.src = "vendor/browser-es-module-loader/dist/browser-es-module-loader.js";
+            document.head.appendChild(loader);
+        });
+    </script>
+
+    <!-- actual script modules -->
     <script type="module">
         // Load supporting scripts
         import * as WebUtil from './app/webutil.js';