Confirmation of a prepaid order (Node.js)

In this use case, the user usually clicks on confirm and is taken to a payment page. There he makes the payment and upon a successful transaction, the user gets redirected to the application where the order gets placed. Usually a moment later, the order gets confirmed by the seller with the latest status update on the fulfillment of the order.

Confirm

Code snippets

Client calls the BAP server to trigger confirm:

    router.post("/local_retail/confirm_prepaid_order", confirmOrder);

    async function confirmOrder({  body }, res) {
        try {
            //  .. Validate the client request before below function
            await generateConfirmOrderRequest(body)
        } catch (error) {
            res.status(500).send(httpResponse("NACK", error));
        }
    };

BAP server generates the protocol request body


    // Code to generate the protocol request body i.e. function generateConfirmOrderRequest() specified above

    async function generateConfirmOrderRequest(clientRequestBody) {
/*
Example Request JSON :
{
    "context": {
        "domain": "nic2004:52110",
        "country": "IND",
        "city": "std:080",
        "action": "confirm",
        "core_version": "0.9.1",
        "bap_id": "https://mock_bap.com/",
        "bap_uri": "https://mock_bap.com/beckn/",
        "bpp_id": "https://mock_bpp.com/",
        "bpp_uri": "https://mock_bpp.com/beckn/",
        "transaction_id": "1209849124",
        "message_id": "12341242345",
        "timestamp": "2021-03-23T10:00:40.065Z"
    },
    "message": {
        "order": {
            "items":[
                {
                    "id": "item_1",
                    "quantity": {
                        "count": 2
                    }
                },
                {
                    "id": "item_2",
                    "quantity": {
                        "count": 1
                    }
                },
            ],
            "billing": {
                "name": "John Doe",
                "address": {
                    "door": "21A",
                    "name": "ABC Apartments",
                    "locality": "HSR Layout",
                    "city": "Bengaluru",
                    "state": "Karnataka",
                    "country": "India",
                    "area_code": "560102"
                },
                "email": "[email protected]",
                "phone": "+919876543210"
            },
            "fulfillment": {
                "type": "home-delivery",
                "tracking": false,
                "start": {
                    "location": {
                        "id": "koramangala-4th-block-location",
                        "descriptor": {
                            "name": "Pooja Stores"
                        },
                        "gps": "12.9349377,77.6055586"
                    },
                    "time": {
                        "range": {
                            "start": "2021-06-15T07:09:30.000Z",
                            "end": "2021-06-15T07:10:30.000Z"
                        }
                    },
                    "instructions": {
                        "name": "pick up instructions",
                        "short_desc": "Provide the order id"
                    },
                    "contact": {
                        "phone": "+919999999999",
                        "email": "[email protected]"
                    }
                },
                "end": {
                    "location": {
                        "gps": "12.914028, 77.638698",
                        "address": {
                            "door": "21A",
                            "name": "ABC Apartments",
                            "locality": "HSR Layout",
                            "city": "Bengaluru",
                            "state": "Karnataka",
                            "country": "India",
                            "area_code": "560102"
                        }
                    },
                    "time": {
                        "range": {
                            "start": "2021-06-15T07:11:36.212Z",
                            "end": "2021-06-15T07:12:36.212Z"
                        }
                    },
                    "instructions": {
                        "name": "drop off instructions",
                        "short_desc": "Leave at door step"
                    },
                    "contact": {
                        "phone": "+919876543210",
                        "email": "[email protected]"
                    }
                }
            },
            "quote": {
                "price": {
                    "currency": "INR",
                    "value": "370"
                },
                "breakup": [
                    {
                        "title": "Red Apples",
                        "price": {
                            "currency": "INR",
                            "value": "180"
                        }
                    },
                    {
                        "title": "Green Apples Organic",
                        "price": {
                            "currency": "INR",
                            "value": "170"
                        }
                    },
                    {
                        "title": "Delivery Charges",
                        "price": {
                            "currency": "INR",
                            "value": "20"
                        }
                    }
                ]
            },
            "payment": {
                "uri": "https://api.bpp.com/pay?amt=$640&mode=upi&[email protected]",
                "tl_method": "http/get",
                "params": {
                    "amount": "640",
                    "mode": "upi",
                    "vpa": "[email protected]"
                },
                "type": "ON-ORDER",
                "status": "NOT-PAID"
            }
        }
    }
}
*/
        //The below code generates the above example JSON.
        const transactionId = _.get(clientRequestBody, "transactionId");
        // Returns the Context including MessageId
        const context = createContext(transactionId);
        let confirmRequestBody = {
            context, 
            message: {
                // construct from the request
            }
        }
        //call protocol confirm order
        const response = await callConfirm(confirmRequestBody);
         res
        .status(200)
        .send({ ...response.data, messageId: context["message_id"] });
    }

BAP server calls protocol confirm to the network

    async function callConfirm(confirmRequestBody) {
        // It lookups the registry for BG OR BPP
        let uri = lookup();
        // Construct Header
        const headers = constructAuthHeader(); // Auth Header with digital Signature
        return axios({ url: `${uri}/local_retail/confirm`, method: "POST", data: confirmRequestBody, headers});
    }

BAP receives protocol on_confirm

/*
Example Response JSON:
{
    "context": {
        "domain": "nic2004:52110",
        "country": "IND",
        "city": "std:080",
        "action": "on_confirm",
        "core_version": "0.9.1",
        "bap_id": "https://mock_bap.com/",
        "bap_uri": "https://mock_bap.com/beckn/",
        "bpp_id": "https://mock_bpp.com/",
        "bpp_uri": "https://mock_bpp.com/beckn/",
        "transaction_id": "1209849124",
        "message_id": "12341242345",
        "timestamp": "2021-03-23T10:00:40.065Z"
    },
    "message": {
        "order": {
            "id":"order_1",
            "state":"Order Placed",
            "items":[
                {
                    "id": "item_1",
                    "quantity": {
                        "count": 2
                    }
                },
                {
                    "id": "item_2",
                    "quantity": {
                        "count": 1
                    }
                },
            ],
            "billing": {
                "name": "John Doe",
                "address": {
                    "door": "21A",
                    "name": "ABC Apartments",
                    "locality": "HSR Layout",
                    "city": "Bengaluru",
                    "state": "Karnataka",
                    "country": "India",
                    "area_code": "560102"
                },
                "email": "[email protected]",
                "phone": "+919876543210"
            },
            "fulfillment": {
                "type": "home-delivery",
                "tracking": false,
                "start": {
                    "location": {
                        "id": "koramangala-4th-block-location",
                        "descriptor": {
                            "name": "Pooja Stores"
                        },
                        "gps": "12.9349377,77.6055586"
                    },
                    "time": {
                        "range": {
                            "start": "2021-06-15T07:09:30.000Z",
                            "end": "2021-06-15T07:10:30.000Z"
                        }
                    },
                    "instructions": {
                        "name": "pick up instructions",
                        "short_desc": "Provide the order id"
                    },
                    "contact": {
                        "phone": "+919999999999",
                        "email": "[email protected]"
                    }
                },
                "end": {
                    "location": {
                        "gps": "12.914028, 77.638698",
                        "address": {
                            "door": "21A",
                            "name": "ABC Apartments",
                            "locality": "HSR Layout",
                            "city": "Bengaluru",
                            "state": "Karnataka",
                            "country": "India",
                            "area_code": "560102"
                        }
                    },
                    "time": {
                        "range": {
                            "start": "2021-06-15T07:11:36.212Z",
                            "end": "2021-06-15T07:12:36.212Z"
                        }
                    },
                    "instructions": {
                        "name": "drop off instructions",
                        "short_desc": "Leave at door step"
                    },
                    "contact": {
                        "phone": "+919876543210",
                        "email": "[email protected]"
                    }
                }
            },
            "quote": {
                "price": {
                    "currency": "INR",
                    "value": "370"
                },
                "breakup": [
                    {
                        "title": "Red Apples",
                        "price": {
                            "currency": "INR",
                            "value": "180"
                        }
                    },
                    {
                        "title": "Green Apples Organic",
                        "price": {
                            "currency": "INR",
                            "value": "170"
                        }
                    },
                    {
                        "title": "Delivery Charges",
                        "price": {
                            "currency": "INR",
                            "value": "20"
                        }
                    }
                ]
            },
            "payment": {
                "uri": "https://api.bpp.com/pay?amt=$640&mode=upi&[email protected]",
                "tl_method": "http/get",
                "params": {
                    "amount": "640",
                    "mode": "upi",
                    "vpa": "[email protected]"
                },
                "type": "ON-FULFILLMENT",
                "status": "NOT-PAID"
            }
        }
    }
}
*/
    // Auth middleware authenticates the digital signature of the incoming request
    router.post("/local_retail/on_confirm", auth, onTrack);
    async function onTrack({ body }, res) {
        // Save the response to Database
        await saveToDb(body);
    };

Client polls BAP to get the on_confirm results

    // Endpoint for the client to poll the search data based on the message id
    async function getMessageById(req) {
        try {
            const messageId = _.get(req, "messageId");
            // Get the data using message Id
            const response = await getData(messageId);
            res.status(200).send(httpResponse('ACK', "", response));
        } catch(error) {
            res.status(500).send(httpResponse("NACK", error));
        }
    };