Node.js

Node.js
 Node.js is a server-side platform built on Google Chrome's JavaScript Engine (V8 Engine). Node.js was developed by Ryan Dahl in 2009 and its latest version is v0.10.36.
 Node.js is an open source, cross-platform runtime environment for developing server-side and networking applications. Node.js applications are written in JavaScript, and can be run within the Node.js runtime on OS X, Microsoft Windows, and Linux. 
2.what Features of Node.js ?
* Asynchronous and Event Driven
* Very Fast
*Single Threaded but Highly Scalable
*No Buffering 
*License 

3.Who Uses Node.js?

* Following is the link on github wiki containing an exhaustive list of projects, application and companies which are using Node.js. This list includes eBay, General Electric, GoDaddy, Microsoft, PayPal, Uber, Wikipins, Yahoo!, and Yammer to name a few.



4.What Concepts are in Node.js?

 * The following diagram depicts some important parts of Node.js which we will discuss in detail in the subsequent chapters.

Node.js Concepts
 
  
5.Where to Use Node.js?
  Following are the areas where Node.js is proving itself as a perfect technology    partner.
  • I/O bound Applications
  • Data Streaming Applications
  • Data Intensive Real-time Applications (DIRT)
  • JSON APIs based Applications
  • Single Page Applications



    --Node.js  modules-- 

     1.What is a Module in Node.js?

       * Consider modules to be the same as JavaScript libraries. 
         * A set of functions you want to include in your application.

    --Include Modules--

    * To include a module, use the require() function with the name of the module:

    1.var http = require('http'); 
    * Now your application has access to the HTTP module, and is able to create a server:
    http.createServer(function (req, res) {
        res.writeHead(200, {'Content-Type': 'text/html'});
        res.end('Hello World!');
    }).listen(8080); 

     

    --Create Your Own Modules--

    * You can create your own modules, and easily include them in your applications.
    * The following example creates a module that returns a date and time object:

    exports.myDateTime = function () {
        return Date();
    };  

    Use the exports keyword to make properties and methods available outside the module file.
    Save the code above in a file called "mycreatemodule.js"


    var http = require('http');
    var dt = require('./mycraetemodule');

    ** Include Your Own Module **

    http.createServer(function (req, res) {
        res.writeHead(200, {'Content-Type': 'text/html'});
        res.write("The date and time are currently: " + dt.myDateTime());
        res.end();
    }).listen(8080);


    Initiate demo_module.js:

    C:\Users\Your Name>node demo_module.js








 

Comments

Post a Comment

Popular posts from this blog

How to build a Wall Mounted Family Calendar and Dashboard

Image
  How to build a Wall Mounted Family Calendar and Dashboard with a Raspberry Pi and cheap monitor Sponsored By I love dashboards. I love Raspberry Pis (tiny $35 computers the size of a set of playing cards). And I'm   cheap   frugal. I found a 24" old LCD at Goodwill (a local thrift shop) and bought it but it's been sitting unused in my garage. Then I stumbled on  DakBoard . The idea is simple - A wifi connected wall display for your photos, calendar, news, weather and to-do. The implementation is simple genius. It's a browser that starts up full screen (kiosk mode) and just sits there and updates occasionally. DakBoard provides the private webpage and tools to make that happen. You can certainly build this yourself with any number of open source tools. I chose  DakBoard  because it was simple, beautiful, and I was able to get the whole thing done in less than an hour. I'm sure I'll spend many hours tweaking it through. There's also the very popular  M...
Read more

Build a Node.js API

Image
Build a Node.js API Node.js can be intimidating to beginners. But its flexible structure and lack of strict guidelines makes it seem more complicated than it is. This tutorial is a quick and simple guide to Node.js, the Express framework, and MongoDB, focusing on the fundamental REST routes and basic database interaction. You’ll build a simple API boilerplate that can then be used as the foundation for any app. Who This Tutorial Is For : You should have a basic understanding of REST APIs and CRUD operations, plus basic JavaScript knowledge. I use ES6 (mainly fat-arrow functions), but nothing too complex. For this tutorial, you’ll create the skeleton of a back-end for a note-taking application — think You want to be able to do all four CRUD actions on your notes: create, read, update, and delete. Setting Up If you don’t have Node installed, . In a new directory, run npm init, and follow along with the prompts, giving your app the name of ‘notable’ (or whatever ...
Read more

Using the SoundCloud API with the JavaScript SDK

Image
Using the SoundCloud API Setup a Basic HTML Document We will create a basic HTML page which will serve as our homepage. We will also include the SDK here, so we can make use of its functionality. <!DOCTYPE html> < html > < head > < title > Include SDK - Using SoundCloud API </ title > < script src = " //connect.soundcloud.com/sdk.js " > </ script > </ head > < body > </ body > </ html > Notice that we have included the SDK in our page directly from SoundCloud’s servers. You can also download the SDK and reference to it like: < script src = " sdk.js " > </ script > To test if the SDK gets loaded in your webpage correctly: Open up the page in a browser (Chrome recommended). Open up Developer Console in the browser ( Ctrl + Shift + J , in Chrome). In the Console, type SC and press enter. SC is a Javascript Object created by the SDK which we just inc...
Read more