File download problem

Anon

Hi All,

I seem to have run into a problem. My web site creates a temporary file depending on the data in the web server database ( sybase ). This file is then downloaded by the user.

Now what happens is that suppose the user has already followed the above procedure. There are some changes in the data, so the user wants to download the file again. The new file is generated on the web server ( it contains the changes ), but when user clicks on the link to download the file, he gets the old file. I have tried clearing the cache on the user's machine, but to no avail. The problem still exists. Please help.

Thanx in advance,
Ashutosh

robertsamanek

an easy help is the following: add to the href a random parametr, like:

<a href="myfile.zip?a=45235">Download</a>

where 'a' is a random value. then the target should not be cashed anymore (and anywhere).

Anon

WHY?

Does this mean that you would have the same problem with any file which could potentially change on the server side once the client had downloaded it.

What does the random parameter do?

robertsamanek

well, we had the same problem with some proxies... in case you can not (or you do not) send appropriate headers like Expires and Pragama No-Cache, so you need a help like this...

this helps to say to (with the random number) that the source is different...

growbal

I use the following code in my app, it works fine:

printf(
'<a href="myfile.zip?t=%s">Download</a>',
time() );