Why nodejs return chunked data in request?

Question

When I make a http request, I need to concatenate the response:

request.on('response', function (response) {
var body = '';
response.on('data', function (chunk) {
    body += chunk;
    });
...

Why was that implemented this way? Why not output the whole result?

What if the whole result takes up more memory than you have on your system? — Explosion Pills, May 31 '15 at 18:01
Use express js it may be more suitable for you : [express](http://expressjs.com). You will find it easier to develop NodeJS (it is a bit its purpose in fact). — MacKentoch, May 31 '15 at 18:02
By doing this you're not concatenating the response, but you are concatenating the data in the response as a buffer. — akshay, May 31 '15 at 18:02
@MacKentoch thanks, I already know express, just wanted to understand why should I do it in first place. — Renaro Santos, May 31 '15 at 18:03
@ExplosionPills, good point, but AJAX get() return the whole result and I never saw anyone complaining. — Renaro Santos, May 31 '15 at 18:04

score 1 · Answer 1 · edited May 23 '17 at 10:26

Node only uses a single process, no thread. This mean that if spend a lot of time doing something you can´t process other things, like for example other client requests...

For that reason when you are coding in node, you need code thinking in async way.

In this scenario, the request could be slowly, and the program will wait for this request doing nothing.

I found this: Why is node.js asynchronous?

And this is so interesting as well: http://en.wikipedia.org/wiki/Read%E2%80%93eval%E2%80%93print_loop

score 1 · Answer 2 · answered May 31 '15 at 18:04

What you're getting back is a stream, which is a very handy construct in node.js. Required reading: https://github.com/substack/stream-handbook

If you want to wait until you've received the whole response, you can do this very easily:

var concat = require('concat-stream');

request.on('response', function(response) {
    response.pipe(concat(function(body) {
        console.log(body);
    }));
});

Why nodejs return chunked data in request?

2 Answers2