Question

jQuery :

*cacheBoolean
Default: true, false for dataType 'script' and 'jsonp'
If set to false, it will force requested pages not to be cached by the browser. 
Setting cache to false also appends a query string parameter, "_=[TIMESTAMP]", to the URL.*

my question :

cached by the browser ???

if i have an ASHX handler which returns me :

'<div>lalala</div>'

will this be saved on the browser temporary Internet Files ?

I dont think so….

so where does it saves it ?

Answer 1

jQuery itself does not perform any caching of the AJAX response. Setting cache: false serves only to trick the browser into ignoring its own cache by adding a timestamp to the requested URL.

For example, running:

$.ajax('/ajax_handler.php', { cache: false });

Will result in a request for /ajax_handler.php?_=1323308900002.

Any subsequent request will include a newer timestamp at the end, which will cause the browser to ignore cached versions of the file and request a new copy.

So, all setting cache: true does is instruct jQuery to not append this cache-busting timestamp (the current default anyway), allowing the browser to cache the file as it normally would*.

In summary: any caching that happens is just regular browser caching, the files will be stored however the browser typically stores its cache.

_{* Note that “as it normally would” might mean not caching the file! jQuery doesn’t do anything to ensure caching, it’s up to the browser. If the page sends certain Cache-control or pragma headers, it simply won’t be cached. It would arguably make more sense for jQuery to have a “cacheBust” setting that’s the inverse of cache, because that’s all jQuery can do: attempt to prevent caching.}