OK, can you suggest which hooks to use?
1. It looks like I could add a field to the cart array stored in ‘_ims_order_data’ in wp_postmeta. Is it possible to do this without hacking the ImageStore core? If so, which hook should I use?
2. Then, which hook do I use to update that field? I’ll need to update this wp_postmeta every time the visitor clicks the ‘Download’ button.
I just want to know if I can do this without hacking the core. If that’s not possible, fine, but I’d like confirmation before I do that.