Node JSON output malforms, unable to set HTTP Header: Content-Length to fix

Question

The problem Context & intent I'm using a Node backend to (1) request API data from the Feedly Cloud, (2) output that data in JSON format and then (3) retrieve it from within a JS frontend. This question relates to phase (2) only. Initial issue Whilst trying to print the data for the front-end to retrieve, I noticed that Node cut off mid-stream, leaving malformed JSON. Attempted solution I tried setting response headers for Content-Length before writing the content of the response, to force it to print the whole thing. That worked, around twice. But then it started fussing: Ongoing failure Now the app crashes on function run, claiming that I'm setting HTTP headers AFTER writing the content, or outputting to page, when as far as I'm aware I am not. The code ``` var http = require('http') , authCode = 'xyz'; var FeedlyController = { api: function(req, res) { http.get({ host : "cloud.feedly.com", path : "/v3/"+req.params.resource, headers: { Authorization: "OAuth "+authCode } }, function(…

Accepted Answer

I suspect your data event is firing multiple times (because that's how it works, multiple `data` events and then one final `end` event.)

You might want to read through the readable stream documentation (that's what the `response` object is) http://nodejs.org/api/stream.html#stream_class_stream_readable

I'd try changing your handler to look something like:

```
res.writeHead(200, {
  'Content-Type': 'application/json',
  'Content-Length': Buffer.byteLength(json, 'utf8')
});

response.on('data', function(json){
  res.write(json, 'UTF-8');
});
response.on('end', function(){
  res.end();
});
```

Although you might be able to just pipe it through:

```
response.pipe(res);
```

(Instead of explicitly listening to the data and end events)

Node JSON output malforms, unable to set HTTP Header: Content-Length to fix

Solution

Problem