RESTful Web Services The document introduces REST (REpresentational State Transfer), an architectural style for building distributed systems based on HTTP. It discusses the principles of REST including addressable resources, a uniform interface, representation-oriented communication, statelessness, and hypermedia as the engine of application state (HATEOAS). It also outlines how to design RESTful services by defining an object model, distributed interface, URIs, data formats, and allowed HTTP methods.

1. RESTful Web Services
Juan Sandoval
@juanitodread

2. Agenda
Introduction to REST
Introduction
Principles
Design RESTful services

3. ● Introduction to REST
REST is a set of architectural principles that
answer the following questions:
Why is the web so prevalent and ubiquitous?
What makes the web scale?
How can I apply the architecture of the Web
to my own applications?

4. ● Principles
REST: REpresentational State Transfer
Addressable resources
A uniform, constrained interface
Representation-oriented
Communicate statelessly
Hypermedia As The Engine Of Application State
(HATEOAS)

5. Addressability
Is the idea that every object and resource in your system
is reachable through a unique identifier.
In REST is managed through the use of URIs.
Each HTTP request must contain the URI of the object you
are requesting information
scheme://host:port/path?query#fragment

6. Constrained Interface
You must use the finite set of operations of HTTP. Each
method has a specific purpose and meaning.
Get
Put
Delete
Post
Head
Options

7. Representation-Oriented
The representation is the message body of
your request or response. An HTTP message
body may be in any format the server and
client want to exchange.
HTTP content negotiation is a very powerful
tool when writing web services.

8. Communicate Statelessly
Is the idea that there is no client session data
stored on the server. The server only records
and manages state of the resource it exposes.
If there needs to be session-specific data, it
should be held and maintained by the client
and transferred to the server with each
request as needed.

9. HATEOAS
The idea is use Hypermedia As The Engine Of Application
State. Hypermedia is a document-centric approach with
the added support for embedding links to other services
and information within that document format.
HATEOAS enforces with each request returned from a
server it tells you what new interactions you can do next,
as well as where to go to transition the state of your
applications.

10. Design RESTful Services
Define the object model.
Define a distributed interface through HTTP.
Define a set of URIs that represent the entry points into
our system.
Define the data format that we will use to exchange
information between services and clients.
Define which HTTP methods are allowed by each exposed
URI and what those methods do.

11. Code of the course: e-commerce-rest-api
Thank you!