Here's a discussion of something similar:
I've been thinking about situations like this which are like inventory. You have only one of something to sell, and once it's gone, it should not appear for sale any more. Could be a time slot, or a unique product. In each case, it's unique and should not be shown on the front end, once it's gone.
There should be a way to keep a list of items, and their status (available or unavailable) then use that list to populate a drop down or check boxes or radio buttons. You'd have to change the availability after a purchase, so it does not appear next time.
You'd need to use the gform_pre_render hook to display your available items, then the gform_post_submission hook to change the status of the item to unavailable. It would be a customization but I think it should be possible, without any manual intervention to mark items unavailable.
I know that's not a solution, but just thinking out loud.
Posted 9 years ago on Saturday September 24, 2011 | Permalink