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Flash Cache

Having trouble seeing the most current version every time you update a Flash movie? Here’s a quick tip to help you get over that.

I almost always use SWFObject when embedding a Flash file into an HTML page. I often have problems in seeing the most recent versions when I make incremental updates to a SWF.

To eliminate this, I now add a random query string to my file name. So instead of…

swfobject.embedSWF("myContent.swf", "myContent", "300", "120", "9.0.0");

…I’ll do…

swfobject.embedSWF("myContent.swf?" + Math.random(), "myContent", "300", "120", "9.0.0");

It eliminates the caching problem by tricking the browser into looking for a different file without changing the location of your movie. Not an original trick by any means, but I hope it helps someone out there.


Michael Espinosa said:

Nice little trick, very handy. Thanks.

Posted on July 6, 2008 12:40 PM

Brian Warshaw said:

Yeah, I found the need for this when I was building a Flash MP3 player in Actionscript, though I ended up appending the randomness to the URL that was requesting the playlist. I believe Rails uses the technique for JS and CSS files by default.

Posted on July 10, 2008 04:46 PM

Tory said:

I'll have to keep this in mind for next time... Thanks for the tip.

Posted on July 14, 2008 10:23 PM

David Hemphill said:

Thanks so much for this. A good, simple solution for an annoying problem.

Posted on July 19, 2008 08:29 PM

Aaron said:

Very nice. Where I work we added a Flash piece to the home page and rather than update the name of the SWF each time we can use this technique. Thank you.

Posted on August 6, 2008 12:44 AM

Jack Andrews said:

Daniel, I am a designer in Dallas and an advertising veteran. I am impressed with your site, but even more impressed with your copywriting. Thanks.

Posted on August 27, 2008 10:32 AM

Michael Reiner said:

Immensely useful Dan!
As always, great stuff here.

Posted on August 27, 2008 04:20 PM

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