The document discusses RESTful APIs with Node.js and Express. It begins with an introduction to APIs and contrasts REST and SOAP APIs. It then discusses Node.js and how it enables non-blocking asynchronous I/O. Finally, it provides a basic example of creating an Express server to respond with "Hello World" and discusses how Node.js handles threads without blocking.

1. RESTful API with
Node JS and
Express

2. Agenda
▷ What is API?
▷ Contrasting common types of APIs
▷ What is Node JS and Express?
▷ Installing Express
▷ Coding Session
▷ Q & A
▷ Workshop

3. 1.
What is API?

4. “An API is a precise specification of
the programming instruction and
standards to access a web based
software or web tool acting as a link
between the programmer and the
application.

5. What is an API?
▷ Acronym for Application Program
Interface.
▷ Acts as a bridge between the
programmer and application.
▷ Takes specific requests predefined
when created.
▷ Verifies the requests and then processes
the data.
▷ Gives detailed info on what and how the
request are to be made.

6. REST APIs

7. ▷ REST stands for Representational State Transfer. (ReST)
▷ It is not a framework but Architectural Principle.
▷ Uses HTTP requests which is oriented around verbs and
resources ( GET, POST, PUT, DELETE)
▷ The verbs are applied to resources ( data )
POST something to database.
GET something from Users.
DELETE something from clients.
▷ The request consist of Headers, body and methods.
▷ The response consists of Status Code, Headers and the body.
▷ Caching and Stateless.
▷ Data represented mostly through HTML / XML / JSON.
REST APIs

8. Contrasting types of APIs
REST
▷ Stands for Representational
State Transfer.
▷ Is an Architectural principle.
▷ Permits different data
formats.
▷ Better Performance and
Scalability.
▷ Supports Caching .
▷ Limited to single HTTP
transaction. Expects user to
retry if something fails.
▷ Used in all type of system
apart from some where high
security risk are present.
SOAP
▷ Stands for Simple Object
Access Protocol.
▷ Is a protocol.
▷ Permits only XML.
▷ Scalable but at a very
minimum level.
▷ Doesn’t support caching.
▷ Can ensure ACID
transactions.
▷ Used mostly in High risk
enterprise softwares and
banking softwares.

9. About Node.js
Node.js is not a silver-bullet
new platform that will
dominate the web
development world. Instead,
it’s a platform that fills a
particular need

10. What is challenge in web
development?
Thread handling.

11. Why Node.JS ?
Open
Source
Non -
Blocking
Large
community

12. Asynchronous I/O

13. Blocking&Non-BlockingCode
Blocking Code Example
var fs = require("fs");
var data =
fs.readFileSync('input.txt');
console.log(data.toString());
console.log("Program Ended");
Output
Everything in the file input.txt
Program Ended
Non-Blocking Code Example
var fs = require("fs");
fs.readFile('input.txt', function
(err, data) {
if (err) return
console.error(err);
console.log(data.toString());
});
console.log("Program Ended");
Output
Program Ended
Everything in the file input.txt

14. BasicExample
var http = require("http");
http.createServer(function(request, response){
response.writeHead(200, {'Content-Type':
'text/html'});
response.end('<h1>Hello World</h1>');
}).listen(1234);
console.log("Server running at port 1234");

16. ThankYou