Disable cache for dynamic created Javascript

Question

I've created a dynamic javascript (test.js) file in PHP with Symfony2 and i do not want this file to be cached by browser. When i insert the script test.js 2 times in one page, the first time it's loading directly from the server but for the second time the script is loaded from browser cache. This problem appear on Chrome and IE, on Firefox everything working fine.

Here a live example : https://www.fiduciaireromande.ch/double.html (if you see 3 time same number that mean it's loaded from cache, if 3 different numbers it's loaded from server)

I've tried many different Header() PHP settings it's doesn't change anything.

PS: I can't use random number like test.js?r=923902390 to do the trick i need another solution

This makes me wonder about optimisation techniques at the browser level. Since it's the exact same resource, would chrome or IE even bother making 3 requests ? IE11 network console shows only one request for the js file if we were to believe it. No idea about Chrome. — spenibus
– spenibus, Commented Jul 11, 2015 at 20:11
Try setting a no-cache directive for the URL you are providing your javascript file from, using e.g.: symphonyextensions.com/extensions/page_http_caching — David Sulc
– David Sulc, Commented Jul 11, 2015 at 20:53
David, i'm not using symphony but symfony2. This not helping me — Siol
– Siol, Commented Jul 12, 2015 at 7:49
Could you explain why you can't modify the url ? It would help rule out ideas. — spenibus
– spenibus, Commented Jul 12, 2015 at 18:44
Because its for an ad network and the javascript tag is already live on multiple site, the code cant change — Siol
– Siol, Commented Jul 13, 2015 at 18:50

spenibus · Accepted Answer · 2015-07-13 22:46:40Z

Idea 1 (basic)

Generate the content randomness within javascript on the client side. Make javascript work a little more. This is probably what should be done. It's more reasonable. Unless it's just not possible.

Idea 2 (less reasonable and probably overengineered)

Make the script check its own url and load another (randomized) copy of itself.

// self contained auto cloning facility
(function(){

   // see http://www.2ality.com/2014/05/current-script.html
   var currentScript = document.currentScript || (function() {
      var scripts = document.getElementsByTagName('script');
      return scripts[scripts.length - 1];
   })();

   // get script tag url (self)
   var url = currentScript.getAttribute('src');

   // url doesn't have random part
   if(!url.match(/\?\d+$/)) {

      // create new script tag with random part
      var s = document.createElement('script');
      s.src = url+'?'+Math.round(Math.random()*1000000000);
      document.body.appendChild(s);

      // engage wild brakes
      throw "stop";
   }
})();

// do the actual job below this point

Raphaël Malié · Accepted Answer · 2015-07-12 18:27:45Z

0

If you cannot add a dynamic parameter in the URL (event if I think it's the best way to achieve what you want to do), you can disable the cache with .htaccess like this :

<filesMatch "\.js$">
  FileETag None
  <ifModule mod_headers.c>
     Header unset ETag
     Header set Cache-Control "max-age=0, no-cache, no-store, must-revalidate"
     Header set Pragma "no-cache"
     Header set Expires "Wed, 11 Jan 1984 05:00:00 GMT"
  </ifModule>
</filesMatch>

You need to activate the Apache Header module.

If you cannot use this, you should define your JS file as a route in Symfony, and set these headers in your controller response.

answered Jul 12, 2015 at 18:27

Raphaël Malié

4,0221 gold badge24 silver badges40 bronze badges

Collectives™ on Stack Overflow

Disable cache for dynamic created Javascript

2 Answers 2

Idea 1 (basic)

Idea 2 (less reasonable and probably overengineered)

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Idea 1 (basic)

Idea 2 (less reasonable and probably overengineered)

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related