Introduction to NodeJS/ExpressJS

Chandan Jhunjhunwal

Session -1

13/01/2017

Basics

Async Call

NodeJS

  • NPM
  • NVM
  • package.json
  • Built in modules
  • Third party modules
  • Your own module



var url = require("url");

var parsedURL = url.parse("http://www.example.com/profile?name=barry");

console.log(parsedURL.protocol);  // "http:"
console.log(parsedURL.host);      // "www.example.com"
console.log(parsedURL.query);     // "name=barry"

Built in module



Mustache.render("Hello, {{first}} {{last}}!", {
  first: "Nicolas",
  last: "Cage"
});


Mustache.render("Hello, {{first}} {{last}}!", {
  first: "Sheryl",
  last: "Sandberg"
});

Third Party Module




var MAX = 100;

function randomInteger() {
  return Math.floor((Math.random() * MAX));
}

module.exports = randomInteger;

Your module



1. Find number of 'X' (case insensitive) in a text file from disc 
   using file system 'fs' module.

2. Write console.log at the end of file, check what's gets 
   printed first

Async Calls




var http = require("http");

function requestHandler(request, response) {
  console.log("In comes a request to: " + request.url);
  response.end("Hello, world!");
}

var server = http.createServer(requestHandler);

server.listen(3000);

http server

Node vs Express

Node JS

ExpressJS

// Node http server
var http = require("http");

requestHandler = function(req, res){
  if(req.url === '/'){
        res.end('Home page')
    }
  else {
     res.end("Don't go out of home");   
  }
}

var server = http.createServer(requestHandler);

server.listen(3000)


// Express Server
var express = require('express');

var funApp = express();

funApp.get('/', function(req, res){
  console.log("request received at" + req.url);
  response.send("Hello world!");
})

fundApp.listen(3000, function(){
  console.log('Application Started...');
})

References

Thank You!

Introduction to Event Loops, Node/Express

By Chandan Jhunjhunwal

Introduction to Event Loops, Node/Express

Session - 1

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