Basics from NodeJS This slide will show how to install and start work on NodeJS. Start learning NodeJS the server side JavaScript

1. Hi!

2. WELCOME MESSAGE
Hello
Everyone
Gobinda Karmakar, MCA,Techno India, Saltlake
I will be showing two of the basic uses of NodeJS apart fromm the
project which I am developing.
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https://www.facebook.com/gobi.karmakar
https://www.linkedin.com/in/gobinda-karmakar-99584879/
+91 9804880167, gobindak2@gmail.com

3. Node JS
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4. Introduction
created by Ryan Dahl, 2009
• NodeJS is an open source, cross platform
runtime for server side and networking
application.
• Written in C++, and can run on Linux, Mac,
Windows, FreeBSD.
• It uses JavaScript on the server.
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5. Features of NodeJS
Extremely fast: Node.js is built on Google Chrome'sV8 JavaScript Engine, so its library is very
fast in code execution.
I/O is Asynchronous and Event Driven: All APIs of Node.js library are asynchronous i.e. non-
blocking. So a Node.js based server never waits for an API to return data.The server moves to the
next API after calling it and a notification mechanism of Events of Node.js helps the server to get
a response from the previous API call. It is also a reason that it is very fast.
Single threaded: Node.js follows a single threaded model with event looping.
Highly Scalable: Node.js is highly scalable because event mechanism helps the server to respond
in a non-blocking way.
No buffering: Node.js cuts down the overall processing time while uploading audio and video
files. Node.js applications never buffer any data.These applications simply output the data in
chunks.
Open source: Node.js has an open source community which has produced many excellent
modules to add additional capabilities to Node.js applications.6/23/2018 Gobinda Karmakar 5

6. Why NodeJS ?
Easy to build a
scaleable network
program
Event Driven,
Works on the Non-
Blocking Model
Node.JS programs are
executed by V8
Javascript engine the
same used by Google
chrome browser.
Server side JavsScript
Can HandleThousands
Of Concurrent
ConnectionsWith
Minimal Over Head On
A Single Process
Light weight and
efficient
Have Runtime
EnvironmentsAnd
NPM Library
NodeJSWorksWith
NoSQL asWell
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7. When to Use ?
• Single page applications (web applications in AJAX, mobile
web applications)Node.js has ability to process many
requests with low response times needed. It is also able to
share things like validations between client and server side,
which makes it a good choice for modern web applications
doing a lot of processing on client side.
Node.js is built on great non-blocking event driven architecture
model. In case your project or module can really make
advantage for this model, then go for it. Some of the cases
could be the following:
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8. Anything that requires real-time feedback from
web server such as chat application, messaging
applications or other collaboration tools is good
with Node.js. It will be the best technology for this
type of job. Ruby and Python can do these kind of
features however Node.js will do it exceptionally
great in terms of performance and simplicity of
development.
 Real time web applications:
In case your plan is to build streaming applications
then Node.js is what you need.Traditional web
technologies frequently treat http requests and
responses as atomic events. However, they are
streams and not events. And consequently many
great Node.js applications can be built to take
 Streaming Data:
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9. Mobile applications can benefit most out of
it because they consume data mostly via
web services in form of JSON APIs. It’s as
well perfect for taking care of many requests
that are I/O driven (e.g. operations on
database) and scales nicely.
 Building APIs:
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10. When Not to Use ?
Simple CRUD/HTML apps: While Node.js will eventually
be a tool for writing all kinds of web applications,
however your application won’t mystically get more
traffic just because you write it in Node.js. If large part of
your application is basically rendering HTML based on
some database, using Node.js will not provide a lot of
business benefits yet.
Enterprise applications: If
you’d like to build an
enterprise application
which requires complex
operations, it’s better to
stick to proven
technologies like JAVA,
Python. Node.js still has a
long way to go and is
considered to be rather
young technology and yet
to prove itself.
Heavy CPU utilizing
applications: It’s not good
using Node.js for
applications that are very
heavy on CPU usage and
very light on actual I/O.
Node.js permits to easily
write C++ add-ons, so you
could certainly use it as a
scripting engine on top of
your algorithms.
NodeJS
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11. Lets Start with installation
Pre requisites:
• Go to NodeJS website and download the latest version (https://nodejs.org/en/ )
and install it on your machine
• Windows PowerShell (pre installed on your machine)
we will use it instead of ‘cmd’ because it support ‘ls’ command like we use in Linux Environment
• Atom text editor (https://atom.io/ )
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12. Lets Begin with magic

13. • Make a separate folder for NodeJS practice on your
desktop
• OpenAtom editor
console.log(‘Hello Gobinda’);
save it on your NodeJS folder on your desktop as
hello.js
• Now open upWindows PowerShell and navigate to the
NodeJS folder on your desktop
• Use command
node hello.js
it will display Hello Gobinda on the display window
Creating a separate
environment
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14. • Use command ‘npm init’
• And fill the required fields
Now We NeedTo Create A Package i.e
Jason File
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15. • This code will create a local server on
your machine
We will be using ES2016 code conventions to
create our server
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16. • Type node hello.js to run the created
server
• Go to your browser and type
127.0.0.1:8000
To Run the created server on your machine
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17. • Edit the code with fs function i.e.
filesystem
Lets try to load a file
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18. • And re run the server and type
127.0.0.1:8000 on
your browser again
Add a simple html page
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19. Text editor
Atom
To run the code
A Browser
NodeJS
To power up the server
Windows PowerShell
Graphical Representation
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20. Popular apps built on NodeJS
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21. A single page web module
OurVery FirstWeb Application
I have attached the full folder along with the ppt please check the folder.
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22. THE END
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