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Automatically clearing browser cache when CSS/ theme is modified.

Chethan Barike
10 years ago Feb 04, 2013 7:28am
Bobby Bissett
10 years ago Mar 04, 2013 7:44pm
Henri Sara
10 years ago Mar 05, 2013 7:20am
Matteo Cedroni
6 years ago Dec 23, 2016 1:37pm

I've tried so many solutions...

vaadinBootstrap.js default code, builds css url by this code

var href = url + '/styles.css'; if (version) { href += '?v=' + version; }

You can modify this code (by maven/ant process) to append url with additional query param,
but then Vaadin, at the bootstrap phase, intercepts this as theme change and adds original url in the html head.

A working solution for my Dashboard based project, is a modified version of this class

The modified version contains

head.append("<script>if (sessionStorage.resRefreshed) { /*resources already refreshed*/ } else{ sessionStorage.resRefreshed=true; window.location.reload(); }</script>");

to force the "reload once" behavior

Stephan Grenier
4 years ago Apr 30, 2018 5:21am
Andrea Pravato
3 years ago Jul 16, 2019 1:31pm

Hi! I had the same issue and solved by reloading the css file using javascript: in my main view class MainUI.java, in the init() method, I have also something like this (whenever the new release involves css changes): // I am reloading css to overwrite previous cache JavaScript.getCurrent().execute( "var randomNum = Math.random();" + "var link = document.createElement( "link" );" + "link.href = "./VAADIN/themes/<..appNameHere..>/styles.css?"+randomNum;" + "link.type = "text/css";" + "link.rel = "stylesheet";" + "link.media = "screen,print";" + "document.getElementsByTagName( "head" )[0].appendChild( link );"); This tricks the browser into loading again the css file, which will override the previously cached one. Before of this I have tried to set cache time to zero in vaadin servlet configuration ( @VaadinServletConfiguration(resourceCacheTime = 0,.. ), but this did not seem to work fine in chrome. Reloading css with javascript is working.

Last updated on Jul, 26th 2019
Ali Berg
3 years ago Dec 09, 2019 5:52pm