How to get the applied promo code text?

Question

We have a website built on Sitecore commerce and working on the following requirement.

When user applies a promo/coupon code at checkout, validate the code with a third party system. Is it possible to get the promo code that user has applied, in the IRuleExecutionContext.

I'm aware of creating a custom condition with the Evaluate method. But do not know how to get the applied code here.

Using Sitecore 8.2 update 5 with Sitecore Commerce 8.2.1 update 3

Answer 1

For me it's not a good idea to validate coupon code with a third party system when it was applied for a cart.

You need to validate it on Add coupon to cart.

Try to find IAddCouponToCartPipeline, which has AddCouponToCartBlock. You can replace AddCouponToCartBlock with your custom and add your check before:

public override async Task<Cart> Run(CouponArgument arg, CommercePipelineExecutionContext context)
    {

      ...

      if (!IsYourCouponValid(arg.CouponCode))
      {
        string str = await context.CommerceContext.AddMessage(context.GetPolicy<KnownResultCodes>().ValidationError, "CouponNotValid", new object[1]
        {
          arg.CouponCode
        }, string.Format("Coupon {0} is not valid.", arg.CouponCode));
        return cart;
      }
      cart.GetComponent<CartCouponsComponent>().List.Add(new CartCoupon()
      {
        CouponId = arg.CouponCode,
        Promotion = couponDefinition.Promotion
      });
      return cart;
    }