Web Programming with AJAX, Problem with caching (I think)

Question

Web programmer here - using AJAX (HTML, CSS, JavaScript, AJAX, PHP, MySQL), but for some reason Internet Explorer is acting up (surprise surprise).

AJAX is updating query results on the HTML page, via a PHP script that queries a MySQL Database.

Everything is working fine, except when I use Internet Explorer 8.0 .

There are several php scripts, which allow for the data to be ordered according to certain criteria, and for testing purposes I have attached the mktime field (current time, in the format HH:MM:SS) to the beginning of the results for each query. When I use IE, these times appear to remain constant, whereas with ALL other browsers these times are correct and display the current time.

I think the issue has something to do with caching or something along those lines anyway.

Any thoughts or suggestions welcome...

Answer 1

What I have done is, I have kept the "GET" and added new dummy query parameter to the querystring as follows,

./BaseServlet?sname=3d_motor&calcdir=20110514&dummyParam=datetime

I set dummyParam a value of date object in the javascript so that every time the url is generated browser will treat it as a new url and fetch new (fresh) results.

var d = new Date();
url = url + '&dummyParam='+d.valueOf();

So instead of generating some random numbers this is easy way!

Answer 2

Instead of switching to POST, which can be ugly if you're not really using it to update or create content, you should append a random number to the query string, as in http://domain.com/ajax/some-request?r=123456. If this number is unique for every request you won't have caching problems.

Answer 3

Here is an article on the caching issue.

If your request is a GET change it to a POST, this will prevent the results being cached.

Answer 4

GET requests are cached in IE; switch it to a POST request and it won't be cached anymore.