Lecture 4 - Postman & API

Question 1

GET Request

Answer 1

• Requests data from a specified resource (typically used to retrieve data from a server).
• Query strings are sent in the URL.

/test/demo_form.php?name1=value1&name2=value2

• Can be cached, bookmarked, and remains in browser history.
• Should not be used for sensitive data.
• Restrictions on the datatype: only ASCII characters allowed.
• Has length restrictions and is used only to request data, not modify it.

Question 2

POST Request

Answer 2

• Sends data to a server to create or update a resource.
• Data is stored in the request body.
• Not cached, does not remain in browser history, and cannot be bookmarked.
• No length restrictions.

Question 3

GET vs POST

Answer 3

• GET can be cached and bookmarked; POST cannot.
• GET has length and data type restrictions; POST does not.
• GET data is visible in the URL, making it less secure; POST data is not visible.

Question 4

Other Requests

Answer 4

1. PUT:
   
   • Sends data to create or update a resource.
   • Idempotent: multiple identical requests result in the same outcome.
2. HEAD:
   
   • Similar to GET but without the response body.
   • Useful for checking what a GET request will return without downloading the content.
3. DELETE:
   
   • Deletes the specified resource.
4. PATCH:
   
   • Applies partial modifications to a resource.
5. OPTIONS:
   
   • Describes communication options for the target resource.
6. CONNECT:
   
   • Establishes a two-way communication tunnel with the requested resource.
7. TRACE:
   
   • Performs a message loop-back test to test the path for the target resource, useful for debugging.

Question 5

REST API

Answer 5

• A REST API (Representational State Transfer Application Programming Interface) is a web service that uses the principles and constraints of REST architecture to enable interaction between clients and servers. (A standard way of getting information that is running on a server.)
• RESTful APIs are designed to be stateless, scalable, and easily accessible, allowing clients to perform CRUD (Create, Read, Update, Delete) operations on resources using standard HTTP methods.

Question 6

Key Concepts of REST API

Answer 6

1. Resources:
   
   • Resources are the objects or entities that the API interacts with, such as users, products, or orders. Each resource is identified by a unique URL.
2. Stateless:
   
   • Each request from a client to the server must contain all the information needed to understand and process the request. The server does not store any client context between requests.
3. Client-Server Architecture:
   
   • The client and server are separate entities that communicate over a network. The client makes requests, and the server processes them and returns responses.
4. Uniform Interface:
   
   • A consistent and standardized way of interacting with resources. This typically includes using standard HTTP methods and status codes, and a predictable structure for URLs.
5. Representations:
   
   • Resources can have multiple representations (e.g., JSON, XML). Clients and servers exchange these representations to perform operations on the resources.

Question 7

Benefits of REST API

Answer 7

• Scalability: Statelessness and separation of client and server enhance scalability.
• Flexibility: Can handle multiple types of calls, return different data formats, and support multiple versions.
• Simplicity: RESTful APIs use standard HTTP methods, making them easy to understand and implement.
• Performance: The stateless nature can improve performance by reducing the server load.