How to restrict the number of items purchased

Hi, I'm looking for a virtuemart replacement but I have some specific requirements. We are selling wine, and it can only be shipped in boxes of 12 bottles. Each box can contain individual bottles of different types of wine, but the total number of bottles must always be a multiple of 12. Is it possible to check that the number of bottles ordered is a multiple of 12, and if not, then let the customer adjust their purchase?

Thankyou,

Johannes

Dear Johannes,

Thank you for interesting in our EShop Shopping Cart extension. I am sure that it will be the right choice for you to build a wine online store. Regarding the feature that you asked, it is an outstanding feature which is not supported by EShop. However, I can help you to modify EShop to have it done. So if customer can only checkout products if quantity of products in the cart is multiple of 12. If not, a notice will be display to tell the customer that they should adjust/update the cart.

If you have any more questions, please don't hesitate to let me know.
Sincerely, Giang