Routing

Routing refers to the definition of end points (URIs) to an application and how it responds to client requests.

A route is a combination of a URI, a HTTP request method (GET, POST, and so on), and one or more handlers for the endpoint. It takes the following structure app.METHOD(path, [callback...], callback), where app is an instance of express, METHOD is an HTTP request method, path is a path on the server, and callback is the function executed when the route is matched.

The following is an example of a very basic route.

//install the module and adds to package.json 
//$ npm install --save express
var express = require('express'); 
var app = express();

app.get('/', function (request, response) {
  response.sendFile(__dirname + "/index.html");
});
app.listen(8080);

Example : Route Params

that accespts dynamic arguments in the url

var express = require('express');
var app = express();

var quotes = {
 'einstein': 'Life is like riding a bicycle. To keep your balance you must keep moving',
 'berners-lee': 'The Web does not just connect machines, it connects people',
 'crockford': 'The good thing about reinventing the wheel is that you can get a round one',
 'hofstadter': 'Which statement seems more true: (1) I have a brain. (2) I am a brain.'
 };

app.get('/quotes/:name', function (request, response) {
   
    var name = request.params.name;
    response.send(quotes[name]);
    response.end();
});

app.listen(8080);

Open your browser with address ex: http://localhost:8080/quote/einstein

Example : Url Building

example to call url like this : https://github.com/search?q=nodejs

var url = require('url');
var request = require('request');

var options = {
    protocol: "https:",
    host: "github.com",
    pathname: '/search',
    query: {
        q: "nodejs"
    }
};

var searchURL = url.format(options);

var express = require('express');
var app = express(); // Create server here
app.get('/', function(req,res){
    request(searchURL).pipe(res);
});
app.listen(8080);