Though the Point of Sale application works offline, it is still possible to make RPC calls to the server. The RPC call can be used for any operation; you can use it for CRUD operations, or to perform an action on the server. In this recipe, we will make an RPC call to fetch information about a customer's last five orders.
In this recipe, we will be using the pos_demo module created in the Adding an action button on the keyboard recipe. We will define the action button. When the user clicks on the action button, we will make an RPC call to fetch the order information and display it on the popup.