CODEWITHSUNDEEP
jsonnode.jshttprequest
André Luiz
André Luiz

Reputation: 7322

NodeJS get request. JSON.parse: unexpected token

I'm writing a function in NodeJS that hits an Url and retrieves its json. But I'm getting an error in JSON.parse: unexpected token.

In json validators the string is passing the test when I copy from the browser and paste into the text field, but when I paste the Url for the parser to get the json it show me an invalid message.

I guess it is something with the encoding of the response, but I can;t figure out what it is. Here if my function with an example Url.

function getJsonFromUrl(url, callback)
{
    url = 'http://steamcommunity.com/id/coveirao/inventory/json/730/2/';

    http.get(
        url
        , function (res) {
        // explicitly treat incoming data as utf8 (avoids issues with multi-byte chars)
        res.setEncoding('utf8');

        // incrementally capture the incoming response body
        var body = '';
        res.on('data', function (d) {
            body += d;
        });

        // do whatever we want with the response once it's done
        res.on('end', function () {
            console.log(body.stringfy());
            try {
                var parsed = JSON.parse(body);
            } catch (err) {
                console.error('Unable to parse response as JSON', err);
                return callback(err, null);
            }

            // pass the relevant data back to the callback
            console.log(parsed);
            callback(null, parsed);
        });
    }).on('error', function (err) {
        // handle errors with the request itself
        console.error('Error with the request:', err.message);
        callback(err, null);
    });
}

Can you help me, please?

Thanks in advance for any help.

Upvotes: 1

Views: 2169

Answers (1)

Thomas Urban
Thomas Urban

Reputation: 5071

Concatenating response as string might have issues with encoding e.g. if buffer of every chunk is converted to string with partial UTF-8 encodings at beginning or end. Thus I'd advise to concatenate as buffer first:

var body = new Buffer( 0 );
res.on('data', function (d) {
  body = Buffer.concat( [ body, d ] );
});

Of course it might help to explicitly convert buffer to string on your behalf rather than relying on JSON.parse() doing it implicitly. This might be essential in case of using unusual encoding.

res.on('end', function () {
  try {
    var parsed = JSON.parse(body.toString("utf8"));
  } catch (err) {
    console.error('Unable to parse response as JSON', err);
    return callback(err, null);
  }
        ...

Aside from that the content delivered by given URL seems to be pretty valid JSON.

Upvotes: 2

Related Questions