Stop adding with refresh

[Anon]

I am trying to reinvent the wheel, and have run into a trouble spot.

Building a custom shopping cart, but having trouble with the cart adding items to the db when I hit Refresh or I go Back from the Checkout page. I know there has to be a way to stop this from happening.

Thanx,
Mike

[jordan]

A good way to avoid the refresh problem is to have the form submit to a PHP script that does the database stuff that you need, but have that script print nothing -- instead, at the end of the script, use header("Location: someotherpage.php"); to send them to another page (a "Continue Shopping or Check Out" page, perhaps?) that won't cause any damage if reloaded.

The back button problem is a little trickier. One thing you can do is require users to enable cookies, and then have your script give them a cookie so that if they happen to press the back button, the script will read the cookie and not process the form results a second time. It also helps (perhaps more than the cookie) to have a big message that says "Do not press the back button -- it will screw up your order!"

[Anon]

This is a header problem

to stop this you have to empty your hearder information that was pass from the prev page

or when you refresh the page your GET runs again

[Anon]

A better way is to use cookies to store your cart information until you are ready to check out.

Then store your info into the database at check out.

this gives you less trips to the database and you can use a if statement to not run the same header info twice so that way if the page is refresh it checks for duplicate items in the header and compares them to the cookie info. you would need to do something when you use add and sub an item. this is rough and off the top of my head but it should give you something to look into.

Hope this helps