Question

I have a PHP script that simply takes some data, separates it into tab delimited format, saves it as an .xls file, and then gives user a link to download it.

Works well most of the time, but some people are getting cached versions of the exported .xls file.

What I am thinking I need to do is instead of giving user a direct link to the .xls document, give them a link a PHP page something like this:

deliver_excel_doc.php?file=some_excel_file.xls&

then the deliver_excel_doc.php pulls in the data from the excel doc but does something with headers so the excel doc is not cached and then outputs as xls so the file will be downloaded (or rendered inside excel).

Any ideas on how I can do this (is this concept viable)?

Answer 1

Just add a timestamp to the link getting the Excel File, e.g.

printf('<a href="file.xls?%d">Excel File</a>', time());

Because the timestamp is always different, their browser won’t cache the file.