In this blog, we are going to continue with a few more basic terminology that we will be using very frequently while doing API Testing.
Before Moving Further, I would highly
recommend you to read the part-1 blog as this blog is a continuation of that.
What Are Payloads?
A Payload is the body of the HTTP
request or response.
When browsing the Web, the Browser
usually receives an HTML payload.
This is the web page that you see rendered in the Browser.
Typically when working with an HTTP API
we will send and receive JSON or XML payloads.
What Is JSON?
JSON stands for JavaScript Object
Notation and is a text representation that is also a valid JavaScript code.
Below is the sample JSON File.
JSON can be thought of as a
hierarchical set of key/value pairs where the value can be:
• Object - delimited
by { and }.
• Array - delimited
by [ and ].
• String - delimited
by " and ".
• Integer
An array is a list of objects or
key/value pairs.
The keys are String values e.g.
“projects”, “project”, “id”, etc.
What Is XML?
XML stands for Extensible Markup
Language.HTML is a variant of XML.
For XML to be valid, it must be well
formed, meaning that every opening tag must have a corresponding closing tag,
and strings must have an opening and closing quote.
Below is the Sample XML File
Below is the Sample XML File
Some elements do not have a closing
tag, these are self-closing. The opening tag, instead of ending
with > actually ends with /> you can see this in
the <description nil=" true"/> element.
HTTP messages have the Verb and URL,
followed by a set of headers, and then the optional payload.
POST http://www.google.co.in/apps/mocktracks/reflect.php
HTTP/1.1
Host: www.google.co.in
Content-Type: application/json
Accept: application/json
{"action":"post"}
The headers are a set of metadata for
the message.
Headers are a name, followed by:,
followed by the value of the header.'
The above HTTP message example has
three headers:
• Host
• Content-Type
• Accept
The Host header defines the
destination server domain name.
The Content-Type header tells
the server that the content of this message is JSON.
The Accept header tells the server that the client (application sending the message) will only accept
response payloads represented in JSON.
There are many headers available for
configuring the Authentication details, length of the message, custom metadata,
cookies etc.
What Is Authentication?
When we send a message to a server we
might need to be authenticated i.e. authorized to send a message and
receive a response.
For many Web Applications, you
authenticate yourself in the application by logging in with a username and
password. The same is true for Web Services or HTTP APIs.
If you are not authenticated and try to
send a message to a server then you are likely to receive a response from the
server with a 4xx status code e.g.
• 401 Unauthorized
• 403 Forbidden
There are many ways to authenticate
HTTP requests for HTTP APIs.
Some common approaches you might
encounter are:
• Custom Headers
• Basic Authentication Headers
• Session Cookies
What Is REST?
A REST (Representational State
Transfer) API defines a set of operations where developers can perform requests
and receive responses via HTTP protocol.
Ø REST API’s use HTTP, they can be used by
practically any programming language.
Ø It acts as a medium to propagate communication
between the client and server applications on the World Wide Web.
Ø Stateless – No client data is stored on the server
between requests and session state is stored on the client.
Ø HTTP is the transport protocol for REST
In the Next Blog, we will look into some Rest API Program.
In the Next Blog, we will look into some Rest API Program.
