Fix sri

quizApp/static/js/sri-fallback.js

@@ -1,11 +1,23 @@
 function resource_error(element) {
     var fallback_url = element.dataset.fallback;
+    console.log("Fallback: " + fallback_url);
     var is_js = fallback_url.substr(fallback_url.length - 3) == ".js";
-
-    if (is_js) {
-        document.write("<script src='" + fallback_url + "'></script>");
+    if(is_js) {
+        var script = document.createElement('script');
+        script.src = fallback_url;
+        document.head.appendChild(script);
     } else {
-        // Assume we have jquery loaded by now
-        $('head').append("<link href='" + fallback_url + "' rel='stylesheet'>");
+        var link = document.createElement('link');
+        link.href = fallback_url;
+        link.rel = "stylesheet";
+        document.head.appendChild(link);
+    }
+}
+
+function check_js_error(condition, fallback) {
+    if(!condition) {
+        var script = document.createElement('script');
+        script.src = fallback;
+        document.write("<script src='" + fallback + "></script>");
     }
 }

quizApp/templates/layout.html

@@ -24,6 +24,10 @@
           integrity="sha256-cCueBR6CsyA4/9szpPfrX3s49M9vUU5BgtiJj06wt/s="
           data-fallback="{{ url_for('static', filename='js/jquery.min.js') }}"
           crossorigin="anonymous" onerror="resource_error(this)"></script>
+    <script defer>
+      check_js_error(window.jQuery,
+      "{{ url_for('static', filename='js/jquery.min.js') }}")
+    </script>
     <link rel="stylesheet"
           href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"
           integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u"
@@ -34,6 +38,10 @@
             data-fallback="{{ url_for('static', filename='js/bootstrap.min.js') }}"
             integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa"
             crossorigin="anonymous" onerror="resource_error(this)"></script>
+    <script defer>
+      check_js_error(typeof $().emulateTransitionEnd == "function",
+      "{{ url_for('static', filename='js/bootstrap.min.js') }}")
+    </script>
     <link href="{{ url_for('static', filename='css/main.css') }}" rel="stylesheet">
     <script defer src="{{ url_for('static', filename='js/frame.js') }}"></script>
     <script defer src="{{ url_for('static', filename='js/common_ajax.js') }}"></script>
@@ -45,10 +53,18 @@
               integrity="sha384-FFgGfda92tXC8nCNOxrCQ3R8x1TNkMFqDZVQdDaaJiiVbjkPBXIJBx0o7ETjy8Bh"
               data-fallback="{{ url_for('static', filename='js/html5shiv.min.js') }}"
               crossorigin="anonymous" onerror="resource_error(this)"></script>
+      <script defer>
+        check_js_error(window.html5,
+        "{{ url_for('static', filename='js/bootstrap.min.js') }}")
+      </script>
       <script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"
               integrity="sha384-ZoaMbDF+4LeFxg6WdScQ9nnR1QC2MIRxA1O9KWEXQwns1G8UNyIEZIQidzb0T1fo"
               data-fallback="{{ url_for('static', filename='js/respond.min.js') }}"
               crossorigin="anonymous" onerror="resource_error(this)"></script>
+      <script defer>
+        check_js_error(respond,
+        "{{ url_for('static', filename='js/respond.min.js') }}")
+      </script>
     <![endif]-->
     {% block head %}{% endblock %}
   </head>

quizApp/templates/macros.html

@@ -209,7 +209,11 @@
         defer
         integrity="sha384-ohw6o2vy/chIavW0iVsUoWaIPmAnF9VKjEMSusADB79PrE3CdeJhvR84BjcynjVl"
         data-fallback="{{ url_for('static', filename='js/moment.min.js') }}"
-        crossorigin="anonymous" onerror="resource_error(this)"></script>
+        crossorigin="anonymous"></script>
+<script defer>
+check_js_error(moment,
+      "{{ url_for('static', filename='js/bootstrap.min.js') }}")
+</script>
 <script src="{{ url_for('static', filename='js/bootstrap-datetimepicker.min.js') }}"
         defer></script>
 <script defer src="{{ url_for('static', filename='js/form.js') }}"></script>
@@ -223,12 +227,20 @@
         integrity="sha384-89aj/hOsfOyfD0Ll+7f2dobA15hDyiNb8m1dJ+rJuqgrGR+PVqNU8pybx4pbF3Cc"
         data-fallback="{{ url_for('static', filename='js/jquery.dataTables.min.js') }}"
         defer
-        crossorigin="anonymous" onerror="resource_error(this)"></script>
+        crossorigin="anonymous"></script>
+<script defer>
+check_js_error(jQuery().DataTable,
+      "{{ url_for('static', filename='js/jquery.dataTables.min.js') }}")
+</script>
 <script src="https://cdn.datatables.net/1.10.12/js/dataTables.bootstrap.min.js"
-        integrity="sha384-SR1gffNfWzqensZ3u8O8AkytPBwtg4pKQuOrHUvvCuAxqcoAE4LWPryg4o+1Y9uP"
+        integrity="sha384-SR1gfNfWzqensZ3u8O8AkytPBwtg4pKQuOrHUvvCuAxqcoAE4LWPryg4o+1Y9uP"
         data-fallback="{{ url_for('static', filename='js/dataTables.bootstrap.min.js') }}"
         defer
-        crossorigin="anonymous" onerror="resource_error(this)"></script>
+        crossorigin="anonymous"></script>
+<script defer>
+check_js_error($.fn.dataTable.ext.renderer.pageButton.bootstrap,
+      "{{ url_for('static', filename='js/dataTables.bootstrap.min.js') }}")
+</script>
 <link rel="stylesheet"
       href="https://cdn.datatables.net/1.10.12/css/dataTables.bootstrap.min.css"
       data-fallback="{{ url_for('static', filename='js/dataTables.bootstrap.min.js') }}"