Deparsing integer stored in req.body in node.js using Express

Question

I am passing data to my back-end server. I am using JavaScript and Node.JS with the Express library. I am running the backend on port 80 and the frontend on 8080. I am trying to pass data which I can do for strings with no problem, but when I try and pass integers (or dates), I get undefined. The relevant front end code is:

                    var params = '{ \"clientUIC\":  \"'+myClientUIC+'\", \"clientName\": \"'+myClientName+'\", \"clientGroup\": \"' + myClientGroup+ '\", \"clientNACE\": \"' + myNACE +'\", \"creditLine\": \"' + myCreditLine + '\", \"creditLineDate\": \"' + myCreditLineDate + '\", \"clientCurrency\": \"' + myCurrency + '\", \"clientCity\": \"' + myClientCity + '\", \"clientCountry\": \"' + myClientCountry + '\"}';
                console.log("params " + params);

                var xhr = new XMLHttpRequest();
                xhr.open("POST", "http://localhost:80/deploy_client", true);
                xhr.setRequestHeader('Content-Type', 'application/json');
                xhr.send(params);

An example of the formed JSON is:

params { "clientUIC": "ABC123", "clientName": "Client 180", "clientGroup": "Group 5", "clientNACE": "J", "creditLine": "85000000000", "creditLineDate": "1579651200", "clientCurrency": "EUR", "clientCity": "Den Haag", "clientCountry": "NLD"}

When I read it in the node.js backend, it is fine for strings but not for the numbers. I am reading req.body as follows:

    app.post('/deploy_client', (req, res) => {

    var myClientUIC = req.body.clientUIC;
    myClientUIC = convertStringX(myClientUIC, 16);
    console.log("myClientUIC "+ myClientUIC);
... 
    var myCreditLine = req.body.clientCreditLine;
    console.log("myCreditLine "+ myCreditLine);
    var myCreditLineDate = req.body.clientCreditLineDate;
    console.log("myCreditLineDate "+ myCreditLineDate);
... 

For the strings, req.body. works perfectly but for credit line and credit line date console.log returns undefined.

How do I properly deparse the JSON in node.js?

Answer 1

The params you are looking for are missing in your body request

In my opinion you should stringify an object instead of concatenating a string for your request body, it would be easier to read.

  var params = { 
    clientUIC:  myClientUIC,
    clientName: myClientName,
    clientGroup: myClientGroup,
    clientNACE: myNACE,
    // There is no clientCreditLine
    creditLine: myCreditLine,
    // There is no clientCreaditLineDate
    creditLineDate: myCreditLineDate,
    clientCurrency: myCurrency,
    clientCity: myClientCity,
    clientCountry: myClientCountry
  }';

  console.log(params);

  const strParams = JSON.stringify(params);

  console.log(strParams);

  var xhr = new XMLHttpRequest();
  xhr.open("POST", "http://localhost:80/deploy_client", true);
  xhr.setRequestHeader('Content-Type', 'application/json');
  xhr.send(strParams);