Comments on: How to stop IE from caching AJAX requests http://www.rawseo.com/news/2009/04/02/how-to-stop-ie-from-caching-ajax-requests/ A blend of programming and seo Tue, 23 Mar 2010 05:55:58 -0400 hourly 1 By: ??????? » [Web] ???? http://www.rawseo.com/news/2009/04/02/how-to-stop-ie-from-caching-ajax-requests/comment-page-1/#comment-306 ??????? » [Web] ???? Thu, 09 Apr 2009 02:57:36 +0000 http://www.rawseo.com/news/?p=537#comment-306 [...] How to stop IE from caching AJAX requests [...] [...] How to stop IE from caching AJAX requests [...]

]]> By: Rahul Batra http://www.rawseo.com/news/2009/04/02/how-to-stop-ie-from-caching-ajax-requests/comment-page-1/#comment-138 Rahul Batra Fri, 03 Apr 2009 17:34:04 +0000 http://www.rawseo.com/news/?p=537#comment-138 In 2nd solution, you could've simply used Math.random() to generate a unique identifier. In 2nd solution, you could’ve simply used Math.random() to generate a unique identifier.

]]> By: thezilch http://www.rawseo.com/news/2009/04/02/how-to-stop-ie-from-caching-ajax-requests/comment-page-1/#comment-126 thezilch Fri, 03 Apr 2009 07:06:49 +0000 http://www.rawseo.com/news/?p=537#comment-126 Somewhat related, IE will use a cached request if POSTing with a Content-Length of 0 -- a POST with no data. We had a case where a GET and POST were made on the same URL. IE would use the cached, GET response for a POST request, when no data accompanied the request. Cache-Control header to the rescue. As for a client-side GET solution, using a header: xmlHttp = createXMLHttpRequest(); xmlHttp.onreadystatechange = handleMessages; xmlHttp.open(”GET”,”script.php?",true); xmlHttp.setRequestHeader("Cache-Control","no-cache, private, max-age=0"); xmlHttp.send(null); Somewhat related, IE will use a cached request if POSTing with a Content-Length of 0 — a POST with no data. We had a case where a GET and POST were made on the same URL. IE would use the cached, GET response for a POST request, when no data accompanied the request. Cache-Control header to the rescue.

As for a client-side GET solution, using a header:

xmlHttp = createXMLHttpRequest();
xmlHttp.onreadystatechange = handleMessages;
xmlHttp.open(”GET”,”script.php?”,true);
xmlHttp.setRequestHeader(”Cache-Control”,”no-cache, private, max-age=0″);
xmlHttp.send(null);

]]> By: Jack Arse http://www.rawseo.com/news/2009/04/02/how-to-stop-ie-from-caching-ajax-requests/comment-page-1/#comment-119 Jack Arse Thu, 02 Apr 2009 19:33:14 +0000 http://www.rawseo.com/news/?p=537#comment-119 You could also use POST instead of GET as IE doesn't cache that. You could also use POST instead of GET as IE doesn’t cache that.

]]> By: tedivm http://www.rawseo.com/news/2009/04/02/how-to-stop-ie-from-caching-ajax-requests/comment-page-1/#comment-118 tedivm Thu, 02 Apr 2009 19:28:05 +0000 http://www.rawseo.com/news/?p=537#comment-118 Try these headers instead- header( “Last-Modified: ” . gmdate( “D, d M y H:i:s T”, time() + 3600)); By putting this a little bit in the future you can make up for the fact that some people's clocks aren't synced with yours. Alternatively, you could simply remove this header altogether, as without a validation most systems won't cache. header( “Cache-Control: no-cache, must-revalidate, no-store, max-age=0” ); An important note on Cache-Control- the "no-cache" attribute just tells the client not to give out the content without checking back with the server, while the "no-store" attribute tells the client not to even bother storing the content at all. This website is a great resource for this- http://www.mnot.net/cache_docs One final note- sometimes apache will add additional headers. You may want to use something like the firefox "liveheaders" plugin to see what your server is sending back. Try these headers instead-

header( “Last-Modified: ” . gmdate( “D, d M y H:i:s T”, time() + 3600));

By putting this a little bit in the future you can make up for the fact that some people’s clocks aren’t synced with yours. Alternatively, you could simply remove this header altogether, as without a validation most systems won’t cache.

header( “Cache-Control: no-cache, must-revalidate, no-store, max-age=0” );

An important note on Cache-Control- the “no-cache” attribute just tells the client not to give out the content without checking back with the server, while the “no-store” attribute tells the client not to even bother storing the content at all.

This website is a great resource for this- http://www.mnot.net/cache_docs

One final note- sometimes apache will add additional headers. You may want to use something like the firefox “liveheaders” plugin to see what your server is sending back.

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