Node Example: HTTP Client Utilities Module

Node Module.js

//
// An "httputils" module for Node.
//
// Make an asynchronous HTTP GET request for the specified URL and pass the
// HTTP status, headers and response body to the specified callback function.
// Notice how we export this method through the exports object.
exports.get = function(url, callback) {
// Parse the URL and get the pieces we need from it
 url = require('url').parse(url);
 var hostname = url.hostname, port = url.port || 80;
 var path = url.pathname, query = url.query;
 if (query) path += "?" + query;
 // Make a simple GET request
 var client = require("http").createClient(port, hostname);
 var request = client.request("GET", path, { 
 "Host": hostname // Request headers
 }); 
 request.end();
 // A function to handle the response when it starts to arrive
 request.on("response", function(response) {
 // Set an encoding so the body is returned as text, not bytes
 response.setEncoding("utf8");
 // Save the response body as it arrives
 var body = ""
 response.on("data", function(chunk) { body += chunk; });
 // When response is complete, call the callback
 response.on("end", function() {
 if (callback) callback(response.statusCode, response.headers, body);
 });
 });
};
// Simple HTTP POST request with data as the request body
exports.post = function(url, data, callback) {
 // Parse the URL and get the pieces we need from it
 url = require('url').parse(url);
 var hostname = url.hostname, port = url.port || 80;
 var path = url.pathname, query = url.query;
 if (query) path += "?" + query;
 // Figure out the type of data we're sending as the request body
 var type;
 if (data == null) data = "";
 if (data instanceof Buffer) // Binary data
 type = "application/octet-stream";
 else if (typeof data === "string") // String data
 type = "text/plain; charset=UTF-8";
 else if (typeof data === "object") { // Name=value pairs
 data = require("querystring").stringify(data);
 type = "application/x-www-form-urlencoded";
 }
 // Make a POST request, including a request body
 var client = require("http").createClient(port, hostname);
 var request = client.request("POST", path, {
 "Host": hostname, 
 "Content-Type": type
 });
 request.write(data); // Send request body
 request.end(); 
 request.on("response", function(response) { // Handle the response
 response.setEncoding("utf8"); // Assume it is text
 var body = "" // To save the response body
 response.on("data", function(chunk) { body += chunk; });
 response.on("end", function() { // When done, call the callback
 if (callback) callback(response.statusCode, response.headers, body);
 });
 });
};