Resource-based design thinking in Rest API - Mini Project: Build & Apply

Resource-based Design Thinking with REST API

📖 Scenario: You are building a simple REST API for a library system. The system manages books as resources. Each book has a unique ID, a title, and an author.We will create the data structure for books, configure a filter for books by author, implement the core logic to select books by that author, and finally output the filtered list.

🎯 Goal: Build a REST API endpoint that returns a list of books filtered by a given author using resource-based design thinking.

📋 What You'll Learn

Create a dictionary called books with book IDs as keys and dictionaries with title and author as values

Create a variable called filter_author to hold the author name to filter by

Use a dictionary comprehension to create filtered_books containing only books by filter_author

Print the filtered_books dictionary as the output

💡 Why This Matters

🌍 Real World

Filtering resources by attributes is a common task in REST APIs, such as listing books by author or products by category.

💼 Career

Understanding resource-based design thinking and filtering is essential for backend developers building APIs that serve dynamic data based on client requests.

1

DATA SETUP: Create the books dictionary

Create a dictionary called books with these exact entries: 1: {'title': 'The Hobbit', 'author': 'J.R.R. Tolkien'}, 2: {'title': '1984', 'author': 'George Orwell'}, 3: {'title': 'The Silmarillion', 'author': 'J.R.R. Tolkien'}

Rest API

# Create the books dictionary with the given entries
# Your code here

Hint

Remember to use the exact keys and values as shown, with book IDs as keys and dictionaries as values.

2

CONFIGURATION: Set the filter author

Create a variable called filter_author and set it to the string 'J.R.R. Tolkien' to filter books by this author

Rest API

books = {
    1: {'title': 'The Hobbit', 'author': 'J.R.R. Tolkien'},
    2: {'title': '1984', 'author': 'George Orwell'},
    3: {'title': 'The Silmarillion', 'author': 'J.R.R. Tolkien'}
}
# Set the filter_author variable to 'J.R.R. Tolkien'
# Your code here

Hint

Make sure the variable name is exactly filter_author and the value is the exact string.

3

CORE LOGIC: Filter books by author

Use a dictionary comprehension to create a new dictionary called filtered_books that contains only the books from books where the author matches filter_author

Rest API

books = {
    1: {'title': 'The Hobbit', 'author': 'J.R.R. Tolkien'},
    2: {'title': '1984', 'author': 'George Orwell'},
    3: {'title': 'The Silmarillion', 'author': 'J.R.R. Tolkien'}
}
filter_author = 'J.R.R. Tolkien'
# Create filtered_books dictionary with books by filter_author
# Your code here

Hint

Use a dictionary comprehension with the condition to check the author matches filter_author.

4

OUTPUT: Print the filtered books

Write a print statement to display the filtered_books dictionary

Rest API

books = {
    1: {'title': 'The Hobbit', 'author': 'J.R.R. Tolkien'},
    2: {'title': '1984', 'author': 'George Orwell'},
    3: {'title': 'The Silmarillion', 'author': 'J.R.R. Tolkien'}
}
filter_author = 'J.R.R. Tolkien'
filtered_books = {book_id: info for book_id, info in books.items() if info['author'] == filter_author}
# Print the filtered_books dictionary
# Your code here

Hint

Use print(filtered_books) to show the filtered dictionary.

Practice

1. What is the main idea behind resource-based design thinking in REST APIs?

easy

A. Focusing only on database tables

B. Using only POST requests for all actions

C. Designing APIs without any structure

D. Organizing APIs around things like users or products

Solution

1. Step 1: Understand the concept of resource-based design

   Resource-based design means APIs are built around resources, which are things like users, products, or orders.

2. Step 2: Compare options to the concept

   Only Organizing APIs around things like users or products correctly describes organizing APIs around things (resources). Other options describe incorrect or unrelated ideas.

3. Final Answer:

   Organizing APIs around things like users or products -> Option D

4. Quick Check:

   Resource-based design = Organizing APIs around resources [OK]

Hint: Think of APIs as managing 'things' like users or products [OK]

Common Mistakes:

• Confusing resource-based design with database design
• Thinking all requests must be POST
• Ignoring the concept of resources

2. Which HTTP method is typically used to update an existing resource in a REST API?

easy

A. PUT

B. POST

C. GET

D. DELETE

Solution

1. Step 1: Recall HTTP methods and their common uses

   GET retrieves data, POST creates new data, PUT updates existing data, DELETE removes data.

2. Step 2: Identify the method for updating

   PUT is the standard method used to update an existing resource in REST APIs.

3. Final Answer:

   PUT -> Option A

4. Quick Check:

   Update resource = PUT [OK]

Hint: PUT means replace or update a resource fully [OK]

Common Mistakes:

• Using POST to update instead of create
• Confusing GET with update
• Using DELETE for updating

3. Given this REST API call: DELETE /products/123, what is the expected result?

medium

A. Retrieve product with ID 123

B. Create a new product with ID 123

C. Delete product with ID 123

D. Update product with ID 123

Solution

1. Step 1: Analyze the HTTP method and URL

   DELETE method means remove. The URL targets the product resource with ID 123.

2. Step 2: Determine the action

   DELETE /products/123 means delete the product with ID 123 from the system.

3. Final Answer:

   Delete product with ID 123 -> Option C

4. Quick Check:

   DELETE + resource ID = delete that resource [OK]

Hint: DELETE + resource ID means remove that resource [OK]

Common Mistakes:

• Thinking DELETE retrieves data
• Confusing DELETE with POST or PUT
• Ignoring the resource ID in URL

4. You see this API request: POST /users/45. What is wrong with this request in resource-based design?

medium

A. The URL should be /users without ID for creating

B. POST cannot be used to create resources

C. The HTTP method should be PUT

D. POST must include a resource ID in the URL

Solution

1. Step 1: Understand POST usage in REST

   POST is used to create new resources. The URL should point to the collection, not a specific resource ID.

2. Step 2: Analyze the request URL

   Including an ID (like /users/45) with POST is incorrect because the server assigns IDs when creating new resources.

3. Final Answer:

   The URL should be /users without ID for creating -> Option A

4. Quick Check:

   POST to collection URL without ID = correct [OK]

Hint: POST creates; URL should be collection without ID [OK]

Common Mistakes:

• Using POST with resource ID in URL
• Thinking POST updates existing resource
• Confusing POST and PUT URLs

5. You want to design an API to manage orders and their items. Which URL and HTTP method combination best follows resource-based design to update the quantity of item 7 in order 42?

hard

A. POST /orders/42/items with item ID and quantity in body

B. PUT /orders/42/items/7 with updated quantity in body

C. DELETE /orders/42/items/7 to update quantity

D. GET /orders/42/items/7 with quantity in query

Solution

1. Step 1: Identify the resource and action

   The resource is the specific item (ID 7) inside order 42. Updating quantity means modifying this resource.

2. Step 2: Choose correct HTTP method and URL

   PUT is used to update existing resources. The URL should point to the specific item resource: /orders/42/items/7.

3. Final Answer:

   PUT /orders/42/items/7 with updated quantity in body -> Option B

4. Quick Check:

   Update nested resource = PUT to specific item URL [OK]

Hint: Use PUT on specific nested resource URL to update it [OK]

Common Mistakes:

• Using POST to update existing item
• Using DELETE to update data
• Using GET with query to change data