Demonstrates the Direct Post Method.

To implement the Direct Post Method you need to implement 3 steps:

Step 1: Add necessary hidden fields to your checkout form and make your form is set to post to AuthorizeNet.

Step 2: Receive a response from AuthorizeNet, do your business logic, and return a relay response snippet with a url to redirect the customer to.

Step 3: Show a receipt page to your customer.

This class is more for demonstration purposes than actual production use.