Merge pull request #1090 from jitsi/file_loading_err

Prevent from displaying broken page

index.html

@@ -6,6 +6,37 @@
     <script>
         window.indexLoadedTime = window.performance.now();
         console.log("(TIME) index.html loaded:\t", indexLoadedTime);
+        // XXX the code below listeners for errors and displays an error message
+        // in the document body when any of the required files fails to load.
+        // The intention is to prevent from displaying broken page.
+        var criticalFiles = [
+            "config.js",
+            "utils.js",
+            "do_external_connect.js",
+            "interface_config.js",
+            "lib-jitsi-meet.min.js",
+            "app.bundle.min.js",
+            "all.css"
+        ];
+        var loadErrHandler = function(e) {
+            var target = e.target;
+            // Error on <script> and <link>(CSS)
+            // <script> will have .src and <link> .href
+            var fileRef = (target.src ? target.src : target.href);
+            if (("SCRIPT" === target.tagName || "LINK" === target.tagName)
+                && criticalFiles.some(
+                    function(file) { return fileRef.indexOf(file) !== -1 })) {
+                window.onload = function() {
+                    document.body.innerHTML
+                        = "The application failed to load, missing file: "
+                            + fileRef;
+                };
+                window.removeEventListener(
+                    'error', loadErrHandler, true /* capture phase */);
+            }
+        }
+        window.addEventListener(
+            'error', loadErrHandler, true /* capture phase type of listener */);
     </script>
     <script><!--#include virtual="/config.js" --></script><!-- adapt to your needs, i.e. set hosts and bosh path -->
     <script src="utils.js?v=1"></script>