notify user when joining without name provided

app/assets/javascripts/landing.js

@@ -47,16 +47,20 @@
       // a user name is set, join the user into the session
       if (name !== undefined && name !== null) {
         var jqxhr = Meeting.getInstance().getJoinMeetingResponse();
-        jqxhr.done(function(data) {
-          if (data.messageKey === 'wait_for_moderator') {
-            waitForModerator(Meeting.getInstance().getURL());
-          } else {
-            $(location).attr("href", data.response.join_url);
-          }
-        });
-        jqxhr.fail(function(xhr, status, error) {
-          console.info("meeting join failed");
-        });
+        if (jqxhr) {
+          jqxhr.done(function(data) {
+            if (data.messageKey === 'wait_for_moderator') {
+              waitForModerator(Meeting.getInstance().getURL());
+            } else {
+              $(location).attr("href", data.response.join_url);
+            }
+          });
+          jqxhr.fail(function(xhr, status, error) {
+            console.info("meeting join failed");
+          });
+        } else {
+          $('.meeting-user-name').parent().addClass('has-error');
+        }
 
       // if not user name was set it means we must ask for a name
       } else {
@@ -68,6 +72,14 @@
       Turbolinks.visit($('.meeting-url').val());
     });
 
+    $('.center-panel-wrapper').on ('input', '.meeting-user-name', function (event) {
+      if ($(this).val() === '') {
+        $(this).parent().addClass('has-error')
+      } else {
+        $(this).parent().removeClass('has-error')
+      }
+    });
+
     $('.center-panel-wrapper').on ('keypress', '.meeting-user-name', function (event) {
       if (event.keyCode === 13) {
         event.preventDefault();

app/assets/javascripts/meeting.coffee

@@ -63,6 +63,9 @@ class @Meeting
   # Returns a response object
   #    The response object contains the URL to join the meeting
   getJoinMeetingResponse: ->
+    if !@userName
+      showAlert(I18n.enter_name, 4000, 'danger')
+      return false
     return $.get @getURL() + "/join?name=" + @userName, (data) =>
       # update name used to join meeting
       localStorage.setItem('lastJoinedName', @getUserName())

app/assets/javascripts/shared.js.erb

@@ -35,12 +35,15 @@ var loopJoin = function() {
 };
 
 var alertTimeout = null;
-var showAlert = function(html, timeout_delay) {
+var showAlert = function(html, timeout_delay, type) {
+  type = type || 'success'
+
   if (!html) {
     return;
   }
 
   $('.alert-template .alert-message').html(html);
+  $('.alert-template .alert').removeClass('alert-success alert-danger alert-info alert-warning').addClass('alert-'+type);
   $('#alerts').html($('.alert-template').html());
 
   if (timeout_delay) {