Using .bind

bind.js

var fs = require('fs');
var http = require('http');

function MyServer(config_file) {

  this.config = {};

  this.StartServer = function() {
    http.createServer((function (req, res) {
        this.SendResponse(res);
      }).bind(this)).listen(this.config.port, this.config.host, function() {
        console.log("Server is bound.")
      });
  };

  this.SendResponse = function(response) {
    response.writeHead(200, {'Content-Type': 'text/plain'});
    response.end('Hello World\n');
  };

  this.ParseConfig = function(err,json_string) {
    if(err) {
      console.error("Could not open config file: ", err);
      process.exit(1);
    }

    try {
      console.log(json_string);
      this.config = JSON.parse(json_string);
      this.StartServer();
    }
    catch(exception) {
      console.error("There was an error parsing the json config file: ", exception);
      process.exit(1);
    }
  };

  fs.readFile(config_file, 'utf8', (function(err,json_string) { this.ParseConfig(err,json_string); }).bind(this) );
}

var server = new MyServer('config.json');