How is an HTTP POST request made in node.js?

Question

How can I make an outbound HTTP POST request, with data, in node.js?

Answer 1

This my solution for POST and GET.

About the Post method:

If the body is a JSON object, so it's important to deserialize it with JSON.stringify and possibly set the Content-Lenght header accordingly:

      var bodyString=JSON.stringify(body)
      var _headers = {
        'Content-Length': Buffer.byteLength(bodyString)
      };

before writing it to the request:

request.write( bodyString );

About both Get and Post methods:

The timeout can occur as a socket disconnect, so you must register its handler like:

request.on('socket', function (socket) {
        socket.setTimeout( self.timeout );
        socket.on('timeout', function() {
            request.abort();
            if(timeout) return timeout( new Error('request timed out') );
        });
    });

while the request handler is

       request.on('timeout', function () {
          // Timeout happend. Server received request, but not handled it
          // (i.e. doesn't send any response or it took to long).
          // You don't know what happend.
          // It will emit 'error' message as well (with ECONNRESET code).
          req.abort();
          if(timeout) return timeout( new Error('request timed out') );
        });

I strongly suggest to register both the handlers.

The response body is chunked, so you must concat chunks at the data handler:

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

At the end the body will contain the whole response body:

      response.on('end', function() {
        try {
            var jsonResponse=JSON.parse(body);
            if(success) return success( jsonResponse );
        } catch(ex) { // bad json
          if(error) return error(ex.toString());
        }
      });

It is safe to wrap with a try...catchtheJSON.parse` since you cannot be sure that it is a well-formatted json actually and there is no way to be sure of it at the time you do the request.

Module: SimpleAPI

/**
 * Simple POST and GET
 * @author Loreto Parisi (loretoparisi at gmail dot com)
*/
(function() {

  var SimpleAPI;

  SimpleAPI = (function() {

    var qs = require('querystring');

    /**
     * API Object model
     * @author Loreto Parisi (loretoparisi at gmail dot com)
     */
    function SimpleAPI(host,port,timeout,ssl,debug,json) {

      this.host=host;
      this.port=port;
      this.timeout=timeout;
      /** true to use ssl - defaults to true */
      this.ssl=ssl || true;
      /** true to console log */
      this.debug=debug;
      /** true to parse response as json - defaults to true */
      this.json= (typeof(json)!='undefined')?json:true;
      this.requestUrl='';
      if(ssl) { // use ssl
          this.http = require('https');
      } else { // go unsafe, debug only please
          this.http = require('http');
      }
    }

    /**
     * HTTP GET
     * @author Loreto Parisi (loretoparisi at gmail dot com)
     */
    SimpleAPI.prototype.Get = function(path, headers, params, success, error, timeout) {

      var self=this;
      if(params) {
        var queryString=qs.stringify(params);
        if( queryString ) {
          path+="?"+queryString;
        }
      }
      var options = {
        headers : headers,
        hostname: this.host,
        path: path,
        method: 'GET'
      };
      if(this.port && this.port!='80') { // port only if ! 80
        options['port']=this.port;
      }
      if(self.debug) {
        console.log( "SimpleAPI.Get", headers, params, options );
      }
      var request=this.http.get(options, function(response) {

          if(self.debug) { // debug
            console.log( JSON.stringify(response.headers) );
          }

          // Continuously update stream with data
          var body = '';
          response.on('data', function(d) {
              body += d;
          });
          response.on('end', function() {
            try {
              if(self.json) {
                var jsonResponse=JSON.parse(body);
                if(success) return success( jsonResponse );
              }
              else {
                if(success) return success( body );
              }
            } catch(ex) { // bad json
              if(error) return error( ex.toString() );
            }
          });
        });
        request.on('socket', function (socket) {
            socket.setTimeout( self.timeout );
            socket.on('timeout', function() {
                request.abort();
                if(timeout) return timeout( new Error('request timed out') );
            });
        });
        request.on('error', function (e) {
          // General error, i.e.
          //  - ECONNRESET - server closed the socket unexpectedly
          //  - ECONNREFUSED - server did not listen
          //  - HPE_INVALID_VERSION
          //  - HPE_INVALID_STATUS
          //  - ... (other HPE_* codes) - server returned garbage
          console.log(e);
          if(error) return error(e);
        });
        request.on('timeout', function () {
          // Timeout happend. Server received request, but not handled it
          // (i.e. doesn't send any response or it took to long).
          // You don't know what happend.
          // It will emit 'error' message as well (with ECONNRESET code).
          req.abort();
          if(timeout) return timeout( new Error('request timed out') );
        });

        self.requestUrl = (this.ssl?'https':'http') + '://' + request._headers['host'] + request.path;
        if(self.debug) {
          console.log("SimpleAPI.Post",self.requestUrl);
        }
        request.end();
    } //RequestGet

    /**
     * HTTP POST
     * @author Loreto Parisi (loretoparisi at gmail dot com)
     */
    SimpleAPI.prototype.Post = function(path, headers, params, body, success, error, timeout) {
      var self=this;

      if(params) {
        var queryString=qs.stringify(params);
        if( queryString ) {
          path+="?"+queryString;
        }
      }
      var bodyString=JSON.stringify(body)
      var _headers = {
        'Content-Length': Buffer.byteLength(bodyString)
      };
      for (var attrname in headers) { _headers[attrname] = headers[attrname]; }

      var options = {
        headers : _headers,
        hostname: this.host,
        path: path,
        method: 'POST',
        qs : qs.stringify(params)
      };
      if(this.port && this.port!='80') { // port only if ! 80
        options['port']=this.port;
      }
      if(self.debug) {
        console.log( "SimpleAPI.Post\n%s\n%s", JSON.stringify(_headers,null,2), JSON.stringify(options,null,2) );
      }
      if(self.debug) {
        console.log("SimpleAPI.Post body\n%s", JSON.stringify(body,null,2) );
      }
      var request=this.http.request(options, function(response) {

          if(self.debug) { // debug
            console.log( JSON.stringify(response.headers) );
          }

          // Continuously update stream with data
          var body = '';
          response.on('data', function(d) {
              body += d;
          });
          response.on('end', function() {
            try {
                console.log("END", body);
                var jsonResponse=JSON.parse(body);
                if(success) return success( jsonResponse );
            } catch(ex) { // bad json
              if(error) return error(ex.toString());
            }
          });

        });

        request.on('socket', function (socket) {
            socket.setTimeout( self.timeout );
            socket.on('timeout', function() {
                request.abort();
                if(timeout) return timeout( new Error('request timed out') );
            });
        });
        request.on('error', function (e) {
          // General error, i.e.
          //  - ECONNRESET - server closed the socket unexpectedly
          //  - ECONNREFUSED - server did not listen
          //  - HPE_INVALID_VERSION
          //  - HPE_INVALID_STATUS
          //  - ... (other HPE_* codes) - server returned garbage
          console.log(e);
          if(error) return error(e);
        });
        request.on('timeout', function () {
          // Timeout happend. Server received request, but not handled it
          // (i.e. doesn't send any response or it took to long).
          // You don't know what happend.
          // It will emit 'error' message as well (with ECONNRESET code).
          req.abort();
          if(timeout) return timeout( new Error('request timed out') );
        });

        self.requestUrl = (this.ssl?'https':'http') + '://' + request._headers['host'] + request.path;
        if(self.debug) {
          console.log("SimpleAPI.Post",self.requestUrl);
        }

        request.write( bodyString );
        request.end();

    } //RequestPost

    return SimpleAPI;

  })();

  module.exports = SimpleAPI

}).call(this);

Usage:

// Parameters
// domain: example.com
// ssl:true, port:80
// timeout: 30 secs
// debug: true
// json response:true
var api = new SimpleAPI('posttestserver.com', 80, 1000 * 10, true, true, true); 

var headers = {
    'Content-Type' : 'application/json',
    'Accept' : 'application/json' 
};
var params = {
  "dir" : "post-test"
};
var method = 'post.php';

api.Post(method, headers, params, body
    , function(response) { // success
       console.log( response );
    }
    , function(error) { // error
      console.log( error.toString() );
    }
    , function(error) { // timeout
       console.log( new Error('timeout error') );
    });