Web App Changes and Browser Cache Issues

Using 2012r2.1 for a web app deployed as CGI.

Yesterday, I made some changes to a web app that required adding a WebTimer to a page. I compiled and deployed the app to my test server.

When I hit the app for the first time (Chrome 27.x), the app crashed in the browser with something like a “timer is undefined” error.

The solution turned out to be emptying the browser cache. This was true for Firefox 3.6, Safari 6.x, and of course Chrome.

Has anyone else observed this? Would you expect adding a control to a web app to require a browser cache purge?

I had this problem many times.

Certain controls require to empty the cache when you add them to your application. Timer is one of them. Best would be to instruct apache not to cache generated pages of your application.


My other apps are using https. I guess that’s why I haven’t encountered this before.


Do stand-alone apps suffer from this issue? I am guessing they do not cache.

What is the best method to manage caching on Apache 2? I have added these directives to my virtual server which appears to be working although it is not heavily tested yet:

ExpiresActive On
ExpiresDefault A1
Header append Cache-Control must-revalidate

I have read that an appropriately configured browser can override any caching directive if the user is determined. If so, it seems that https is the only practical way to avoid this issue for cgi deployments.

I cannot empty a lot of browser caches every time I update a web app.