Full page reload in some situations

1. If the Management UI lost connection and established it again,
there's a good chance it's now connected to a diffrent RabbitMQ
node, potentially running a different version.

2. If the overview endpoints returns a different version, fully reload
   the page. This only works on the home page, but that's better
   than nothing

Author: mkuratczyk

deps/rabbitmq_management/Makefile

@@ -48,3 +48,4 @@ prepare-dist::
 	mv $(EZ_DIR)/priv/www/css/main.css $(EZ_DIR)/priv/www/css/main-$(PROJECT_VERSION).css
 	$(verbose) sed "s#css/main.css#css/main-$(PROJECT_VERSION).css#" priv/www/index.html \
 		> $(EZ_DIR)/priv/www/index.html
+	echo "management_version = \"$(PROJECT_VERSION)\";" >> $(EZ_DIR)/priv/www/js/global.js

deps/rabbitmq_management/priv/www/js/global.js

@@ -846,6 +846,9 @@ var timer_interval;
 // When did we last connect successfully (for the "could not connect" error)
 var last_successful_connect;
 
+// we want a full page refresh after we were disconnected or if the RabbitMQ version changed
+var needs_full_refresh = false;
+
 // Every 200 updates without user interaction we do a full refresh, to
 // work around memory leaks in browser DOM implementations.
 // TODO: maybe we don't need this any more?
@@ -860,3 +863,6 @@ var chart_data = {};
 var last_page_out_of_range_error = 0;
 
 var oauth;
+
+// version of RabbitMQ we connected to; used to detect version changes
+var management_version = "";

deps/rabbitmq_management/priv/www/js/main.js

@@ -1306,7 +1306,11 @@ function maybe_format_extra_queue_content(queue, extraContent) {
 
 function update_status(status) {
     var text;
-    if (status == 'ok')
+    if (status == 'ok' && needs_full_refresh) {
+        // connection was restored, get the latest CSS/JS
+        needs_full_refresh = false;
+        full_refresh();
+    } else if (status == 'ok')
         text = "Refreshed " + fmt_date(new Date());
     else if (status == 'error') {
         var next_try = new Date(new Date().getTime() + timer_interval);
@@ -1496,6 +1500,7 @@ function check_bad_response(req, full_page_404) {
         clearInterval(timer);
     }
 
+    needs_full_refresh = true;
     return false;
 }
 

deps/rabbitmq_management/priv/www/js/tmpl/overview.ejs

@@ -1,3 +1,10 @@
+<%
+   if(management_version != overview.management_version) {
+     // RabbitMQ was upgraded
+     // full reload to get the latest CSS and JavaScript files
+     needs_full_refresh = true;
+   }
+%>
 <% if(disable_stats) { %>
    <h1>Overview: Management only mode</h1>
 <% } else { %>