I have some information which gets passed from a form and needs to be used once and only once. I can collect it nicely from $_POST but I’m not sure which is the “best” way to ensure that I can only use it once, i.e. I want to avoid the user pressing F5 repeatedly and accessing the function more than once.
My initial thought was to set a session variable and time the function out for a set period of time. The problem with that is thay could have access to the function again after the set period has elapsed.
Better ideas welcomed!
A redirect to another page would be sufficient to break most browser repost-on-refresh behaviour. Setting a cookie on form submit (or a session variable, as you suggest) would also work quite nicely. You could have the form submission page unset the session variable again, such that only a fresh access to the form would permit re-submitting the form.