What is Modules?
A module encapsulates related code into a single unit of code. When creating a module, this can be interpreted as moving all related functions into a file.
How to create Module
Create a module that returns the current date and time:
exports.myDateTime = function () {
return Date();
};
Save the code above in a file called "firstmodule.js"
Now we can include and use the module in any of our Node.js files.
var http = require('http');
var dt = require('./myfirstmodule');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.write("The date and time is currently: " + dt.myDateTime());
res.end();
}).listen(8080);
Save the code above in a file called "demo_module.js", and initiate the file
Initiate demo_module.js in Terminal
C:\Users\Your Name> node demo_module.js
If we want result,We will use this path http://localhost:8080
Node.js HTTP Module
This allows Node.js to transfer data over the Hyper Text Transfer Protocol (HTTP).
var http = require('http');
//create a server object:
http.createServer(function (req, res) {
res.write('Hello World!'); //write a response to the client
res.end(); //end the response
}).listen(8080); //the server object listens on port 8080
Save the code above in a file called "demo_http.js"
Then use below code in terminal
C:\Users\Your Name>node demo_http.js
Then use port to open browser
out put:
Hello World!
Node.js URL Module
Create two html files and save them in the same folder as your node.js files.
var http = require('http');
var url = require('url');
var fs = require('fs');
http.createServer(function (req, res) {
var q = url.parse(req.url, true);
var filename = "." + q.pathname;
fs.readFile(filename, function(err, data) {
if (err) {
res.writeHead(404, {'Content-Type': 'text/html'});
return res.end("404 Not Found");
}
res.writeHead(200, {'Content-Type': 'text/html'});
res.write(data);
return res.end();
});
}).listen(8080);
node demo_fileserver.js
http://localhost:8080/(htmlfilename)
