node js
TRANSCRIPT
Node Js Everything which you should know
Node.js for Beginners
Event programming can be overwhelming for beginners, which can make Node.js difficult to get started with. But don’t let that discourage you, In this article, I will teach you some of the basics of Node.js and explain why it has become so popular.
Introduction
To start using Node.js, you must first understand the differences between Node.js and traditional server-side scripting environments (eg: PHP, Python, Ruby, etc).
Asynchronous Programming
Chances are good that you are familiar with asynchronous programming; it is, after all, the “A” in Ajax. Every function in Node.js is asynchronous. Therefore, everything that would normally block the thread is instead executed in the background. This is the most important thing to remember about Node.js. For example, if you are reading a file on the file system, you have to specify a callback function that is executed when the read operation has completed.
"Node.js uses a module architecture to simplify the creation of complex applications."
You are doing Everything!
Node.js is only an environment – meaning that you have to do everything yourself. There is not a default HTTP server, or any server for that matter. This can be overwhelming for new users, but the payoff is a high performing web app. One script handles all communication with the clients. This considerably reduces the number of resources used by the application. For example, here is the code for a simple Node.js application:
Examples
Node js var i, a, b, c, max;
max = 1000000000;
var d = Date.now();
for (i = 0; i < max; i++) {
a = 1234 + 5678 + i;
b = 1234 * 5678 + i;
c = 1234 / 2 + i;
}
console.log(Date.now() - d);
PHP$a = null; $b = null; $c = null; $i = null;
$max = 1000000000;
$start = microtime(true);
for ($i = 0; $i < $max; $i++) {
$a = 1234 + 5678 + $i;
$b = 1234 * 5678 + $i;
$c = 1234 / 2 + $i;
}
var_dump(microtime(true) - $start);
The following table lists the response times, in milliseconds, for these two simple applications:
Number of iterations Node.js PHP
100 2.00 0.14
10’000 3.00 10.53
1’000’000 15.00 1119.24
10’000’000 143.00 10621.46
1’000’000’000 11118.00 1036272.19
I executed the two apps from the command line so that no server would delay the apps’ execution. I ran each test ten times and averaged the results. PHP is notably faster with a smaller amount of iterations, but that advantage quickly dissolves as the number of iterations increases. When all is said and done, PHP is 93% slower than Node.js!
Node.js is fast, but you will need to learn a few things in order to use it properly.
Modules
Node.js uses a module architecture to simply the creation of complex applications. Each module contains a set of functions related to the “subject” of the module.
Including a module is easy; simply call the require() function, like this
var variable_name('module_name');
Global Scope
Node is a JavaScript environment running in Google’s V8 JavaScript engine.
globalVariable = 1;globalFunction = function () { ... };
Installing New Module
Node.js has a package manager, called Node Package Manager (NPM). It is automatically installed with Node.js, and you use NPM to install new modules. To install a module, open your terminal/command line, navigate to the desired folder, and execute the following command:
npm install module_name
Let move ahead to Javascript Framework
Client FrameworksBackbone, Angular, Ember, etc
Server FrameworksExpress,Tower,Railway,Flatlron, etc
Real-time FrameworksDerby, meteor, SocketStream
Thick Server - Websites
(eg, meetup) Most functionality is still on server, but client pages are highly interactive and may use MVC for organization.
Cutting -Edge Present
Thick-client: Web Apps, Mobile (eg, gmail) Most functionality on client. The server is just REST service marshalling data
Little coding, large pay-off. Great for games.
Node.js(Server)Frameworks
Why we use a Node Framework ?
Why not vanilla Node, or Express?
•Module version compatibilities•Boilerplate code•Authentication•Database setup•Grunt/Make tasks like minification,
css/js compiling (Coffeescript, LESS, Stylus, etc)
•Socket.io•And much more
Railway
>Full Stack Web Framework for Node.js and the Browser. Built on top of Node's Connect and Express, modeled after Ruby on Rails. Built for the client and server from the ground up.
Tower
>Railway is the Node.JS MVC framework based on ExpressJS, fully ExpressJS-compatible. It allows you to build web applications in a similar manner as in Ruby On Rails.
Express
>Express is a minimal and flexible node.js web application framework, providing a robust set of features for building single and multi-page, and hybrid web applications.
Flatlron
No one agrees on frameworks. It's difficult to get consensus on how much or how little a framework should do. Flatiron's approach is to package simple to use yet full featured components and let developers subtract or add what they want.
DerbyMVC framework making it easy to write realtime, collaborative applications that run in both
Node.js and browsers.
Meteor is an open-source platform for building top-quality web apps in a fraction of the time, whether you're an expert developer or just getting started.
Meteor
18 Reasons Developers Are Using It for Cloud, Mobile
Two ThirdTwo-thirds of Americans access the Web through
mobile devices, according to Engine Yard research
Thirty-Four Percent
And 34 percent of the world's top 100 Websites are using HTML5.
The Rise of the real-time Web
Engine Yard says the growth of mobile plus the popularity of HTML5 equals the rise of the real-time Web.
And the real-time Web requires real-time technology, such as Node.js.
Event-Driven:- Node.js is a development framework that uses an event-driven, non-blocking I/O.
Built on Javascript :- Node.js is built on JavaScript to unify front-end and server-side architectures.
High Performance :- Node.js is ideal for high-performance, highly scalable, distributed real-time Web applications.
GitHub Status :- Node.js is the second-most-watched repository on the GitHub Web-based hosting service-
second only to Bootstrap.
Ruby on Rails :- Node.js is more watched than Ruby on Rails on GitHub. Bootstrap is first, Node.js second, jQuery third and Rails fourth.
Node Package Manager :- Node Package Manager or NPM is a package manager and distribution system for Node.js. NPM has 12,000 modules and 3,800 active package authors.
LinkedIn is a prominent user of Node.js. On the server side, LinkedIn's entire
mobile software stack is completely built in Node.js. The company went from
running 15 servers with 15 instances on each physical machine to just four
instances that can handle two times the traffic.
Walmart
Walmart re-engineered its mobile app to be powered by Node.js and pushed all its JavaScript processing to the server.
Ebay
eBay recently launched ql.io, a gateway for HTTP APIs, using Node.js as the runtime stack. eBay was able to tune a regular quality Ubuntu workstation to handle more than 120,000 active connections per Node.js process with each connection consuming about 2K of memory.
Key Apps
Node.js is a good choice for building networked multiplayer games, interactive Websites and tools, Web analytics and online chat systems.
Why Developer Love Node.js
Reason 1:It's JavaScript, the language of the Web.Reason 2:It supports code reuse at every level: browser,
server side and database.Reason 3:It has a strong, passionate community.Reason 4:It offers performance and scalability.Reason 5:It leads to developer happiness.