Drupal 8：仅当用户拥有足够的积分时才添加到购物车

Question

I've a site where transactions are based purely on credits. No actual money is exchanged. In such a case, I want to restrict users from adding products to cart if they do not have credits to do so.

In steps of how this should be accomplished, here is the sequence of events which I think should work :

Whenever somebody tries to add a product :

• Use Rule "Before adding product to cart"
• I need to get the value of the following :
  • Get user credits
  • Get sum of current product + cart value
• Check for condition if credits is greater than product + cart.
• If true, add product to cart else display "Not enough credits".

I use the loyalty points module for the user credits.

How can I set up the rules for this scenario?

Answer 1

我没有使用模块，而是按照lamp5的建议在commerce_add_to_card_form上使用了custom_validation函数