Preventing browser caching on web application upgrades

I have a quite troublesome issue which I didn't find a good solution for yet.

I allow caching of all my application static files (JS, CSS and images) by browser for performance.

Problem is, when I'm doing upgrades, the users still use th开发者_JAVA技巧e old version from their cache, which often breaks the application, and requires clearing the cache every time to solve the problem.

Is there any good multi-browser approach which still allows caching the files, but can force to reload them when needed?

Thanks for any info.

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Append somethign to the URL as parameter, e.g. myresource.css?version=1. The file will be servered correctly, that's a trick to force reloading the cache. You only need to generate the html page dynamically.

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I've heard talk of using version numbers in the filenames you want you users caching, but I can't speak to how "good" that is compared to other options.

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Options I can think of:

• Reduce the cache TTL
• Store the cacheable stuff in a versioned directory tree, e.g.:
  • /app/1.2/css/
  • /app/1.2/js/

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You can use below format for auto random versioning

for js file:

<script type="text/javascript" src="js/app.js?seq=<%=DateTime.Now.Ticks%>"></script>

and for css file:

<link rel="stylesheet" type="text/css" href="Styles/styles.css?seq=<%=DateTime.Now.Ticks%>" />