How to capture response body from API in NodeJS

Question

I am new to NodeJS and I am practicing a small project. I have this code which sends request to my NodeJS express server via API endpoint.

        var XHR = new XMLHttpRequest();
        var merchants = ['f6ea7039-de8e-4403-bb63-d348dd502dc8', 'c2a08bfa-db18-4e08-8a08-f4e04dea7e58',
                            'e02ed2a4-06f4-403b-ad1e-f72b55e0681d'];
        //set up the transfer request
        XHR.open('POST', apiUrl + '/transfer', true);

        XHR.setRequestHeader("Content-Type", "application/json; charset=utf-8");
        XHR.withCredentials = true;

        var data = JSON.stringify({
            //merchantId: merchants[(Math.floor((Math.random() * 200))/100)],
            merchantId: 'f6ea7039-de8e-4403-bb63-d348dd502dc3',
            amount: (Math.floor((Math.random() * 1000) + 100)/100),
            currency: 'EUR',
            description: 'Book 

        // Define what happens on successful data submission
        XHR.addEventListener("load", function(event) {
            console.log(event);
            // execute callback once response is received
            if (event.target.status === 200) {
                done(XHR.response);
            }
        });

        XHR.send(data)

and in my server side I have this code:

function getMerchantName(query) {
                return new Promise(function(resolve,reject){

                    pool.query(query, [tr.merchantId], function(error, result){

                        // error ? reject(error) : resolve(result);
                        if(result[0]){
                            return resolve(result);
                        }else{
                            return reject(error);
                        }

                    });

                });
            }

            getMerchantName(sql)
            .then(result => {
                tr.secondaryName = result[0].mName;
                console.log("Secondary Name: ",tr.secondaryName);
                conn.release();
                getUrl();
            })
            .catch(function(error){
                console.log('Rejected', error);
                // res.send(400, {message: 'Merchant Not Found'});
                res.status(403).send({message: 'Merchant Not Found'});
            });

So when the merchant id is not found, I throw (via promise's catch) a response to res.status(403).send({message: 'Merchant Not Found'});

I can only access the error status through XHR.addEventListener load event but not the response body. How can I access this response body to display in client side?

Answer 1

I think you should use express bodyparser :

during init:

app.use(bodyParser.json())

and here is an example request handler:

app.get('/', (req, res) => console.log(req.body))