I want to do something like this but this is throwing an error and I can't seem to use JSON.stringify either. Is there a way to do this?
var http = require('http')
http.createServer(function(req, res) {
res.end(req);
}).listen(3000);
asked May 29, 2014 at 23:45
Babistalikesflyingonrails
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1 Answer
Start with something simple like this:
var http = require('http');
http.createServer(function(req, res) {
res.write(req.url);
res.end();
}).listen(3000);
If you want to echo back the request, you need to think about what parts of it. HTTP requests have a header and a body. The header is already available when the handler function is called, but the body is a stream that you need to read chunk by chunk, and you can then decide to stream it straight back, parse it, transform it, or whatever. There are lots of examples out there to get started.
Here's a piped version.
var http = require('http');
http.createServer(function(req, res) {
req.pipe(res);
}).listen(3000);
And I test it like so:
curl -X POST -d 'foo=bar' localhost:3000/hello/foo
foo=bar%
This version gives me some valid output put it's not in JSON format. As you can see, the req object has tons of internal state having to do with server side programming that is unrelated to the content of the incoming HTTP request. Thus it's not the right way to get at the request DATA, which is not the same as the req object programming interface.
var util = require('util');
var http = require('http');
http.createServer(function(req, res) {
res.write(util.inspect(req));
res.end();
}).listen(3000);
{ _readableState:
{ highWaterMark: 16384,
buffer: [],
length: 0,
pipes: null,
pipesCount: 0,
....etc
Here's a version that sends the request headers back as JSON:
var http = require('http');
http.createServer(function(req, res) {
res.setHeader('Content-Type', 'application/json');
res.write(JSON.stringify(req.headers));
res.end();
}).listen(3000);
And the response:
curl -v localhost:3000
* Adding handle: conn: 0x7fd983804000
* Adding handle: send: 0
* Adding handle: recv: 0
* Curl_addHandleToPipeline: length: 1
* - Conn 0 (0x7fd983804000) send_pipe: 1, recv_pipe: 0
* About to connect() to localhost port 3000 (#0)
* Trying 127.0.0.1...
* Connected to localhost (127.0.0.1) port 3000 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.30.0
> Host: localhost:3000
> Accept: */*
>
< HTTP/1.1 200 OK
< Content-Type: application/json
< Date: Fri, 30 May 2014 00:10:02 GMT
< Connection: keep-alive
< Transfer-Encoding: chunked
<
* Connection #0 to host localhost left intact
{"user-agent":"curl/7.30.0","host":"localhost:3000","accept":"*/*"}%
2 Comments
Babistalikesflyingonrails
when i do a console.log(req) in my server code.. the object it logs out.. there is no way to send that back?
Peter Lyons
Yes, you can send some version of "it" back, but the
req object is not a pure data object. It's an Object-Oriented-Programming object meaning it has functions and data and lots of references, etc. It is intended to facilitate programming, not to be a data representation of the request. There are ways using util.inspect and JSON.stringify to send something back based on it, but really you should think about the request headers and body as data separate from the req programming interface.
res.end(req);to do? That callback function is already in the context of a single connection, so calling res.end() will end that particular connection. The callback is called each time for each connection; you don't have to reference the request in the response.