CODEWITHSUNDEEP
javascriptjsonnode.js
Bjelke
Bjelke

Reputation: 3

Can't make new fields in object if it doesn't exist

I currently have this code that get information from an API and uses gathered information and write it to a JSON file.

var xp;
fs.readFile('./xp.json', 'utf8', (err, data ) => {
    if (err) throw err;
    xp = JSON.parse(data);
});

console.log(m['id'] + " " + m['channel_id'] + " " + m['username']);

var usr = m['id'];
if (!xp[usr])
    xp[usr] = {xpp: 0};
xp[usr].xpp++;
fs.writeFile("./xp.json", JSON.stringify(xp), (err) => {
    if (err) console.error(err);
});

When I run this I get this error message: Error MSG image

So I guess the problem is with the if (!xp[usr]) xp[usr] = {xpp: 0};

My intentions with that line is:

if it's no field in the json object called usr
...
make a field looking like this:
string of usr = {
   xpp = 0
}

I have been stuck on this one for some hours now. Any suggestions?

full function:

    var infoUrl = "https:widget.json";
function giveXP(xyz) {
  console.log("Interval Started");
  request(xyz, function(error, response, body){
    if(!error && response.statusCode == 200){
      var parsedData = JSON.parse(body);
      var memberz = parsedData['members'];
      memberz.forEach(function(m){
        if(m['channel_id']){
          var xp;
          fs.readFile('./xp.json', 'utf8', (err, data ) => {
            if (err) throw err;
            xp = JSON.parse(data);
            console.log(m['id'] + " " + m['channel_id'] + " " + m['username']);
            var usr = m['id'];
            if (!xp[usr]) xp[usr] = {xpp: 0};
            xp[usr].xpp++;
          });
          fs.writeFile("./xp.json", JSON.stringify(xp), (err) => {
            if (err) console.error(err);
          });
        }
      });
    }
  });
} setInterval(giveXP, 3000, infoUrl);

Upvotes: 0

Views: 69

Answers (2)

t3__rry
t3__rry

Reputation: 2849

Perhaps xp indeed doesn't exist at that time due to the fact that readFile is asynchronous. So you need to move you logic in the callback:

fs.readFile('./xp.json', 'utf8', (err, data ) => {
  if (err) throw err;
  xp = JSON.parse(data);

  if (!xp[usr]) {
    xp[usr] = {xpp: 0};
  }
  xp[usr].xpp++;
  fs.writeFile("./xp.json", JSON.stringify(xp), (err) => {
    if (err) console.error(err);
  });
});

Upvotes: 0

Kalleshwar Kalshetty
Kalleshwar Kalshetty

Reputation: 544

you need to access xp[usr] once the fs.read gives you result. as its async you have to put your code in its callback. please take a look of below code

  var xp;
  fs.readFile('./xp.json', 'utf8', (err, data ) => {
    if (err) throw err;
    xp = JSON.parse(data);
    console.log(m['id'] + " " + m['channel_id'] + " " + m['username']);
    var usr = m['id'];
    if (!xp[usr]) xp[usr] = {xpp: 0};
    xp[usr].xpp++;
  });

  fs.writeFile("./xp.json", JSON.stringify(xp), (err) => {
    if (err) console.error(err);
  });
  // ...

Upvotes: 1

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