Hierarchical resource paths in Rest API - Mini Project: Build & Apply

Hierarchical Resource Paths in REST API

📖 Scenario: You are building a simple REST API for a library system. The system has books and each book has chapters. You want to create hierarchical resource paths to access chapters of specific books.

🎯 Goal: Build a REST API with hierarchical resource paths to get chapters of a specific book using URL paths like /books/{book_id}/chapters/{chapter_id}.

📋 What You'll Learn

Create a dictionary called library with books and their chapters

Create a variable called book_id to select a specific book

Use a hierarchical path string to access a chapter of the selected book

Print the chapter title using the hierarchical resource path

💡 Why This Matters

🌍 Real World

Hierarchical resource paths are used in REST APIs to organize and access nested resources like books and chapters.

💼 Career

Understanding hierarchical paths helps in designing clear and scalable APIs for web services.

1

Create the library data structure

Create a dictionary called library with these exact entries: "book1" with chapters {"chapter1": "Introduction", "chapter2": "Basics"} and "book2" with chapters {"chapter1": "Getting Started", "chapter2": "Advanced Topics"}.

Rest API

# Create the library dictionary with books and chapters
# Your code here

Hint

Think of library as a dictionary where each book ID maps to another dictionary of chapters.

2

Select a book using a variable

Create a variable called book_id and set it to the string "book1" to select the first book.

Rest API

library = {
    "book1": {"chapter1": "Introduction", "chapter2": "Basics"},
    "book2": {"chapter1": "Getting Started", "chapter2": "Advanced Topics"}
}
# Create a variable book_id and set it to "book1"
# Your code here

Hint

Use a simple string variable to hold the book ID.

3

Access a chapter using hierarchical resource path

Create a variable called chapter_title that accesses the chapter with key "chapter2" inside the book selected by book_id from the library dictionary.

Rest API

library = {
    "book1": {"chapter1": "Introduction", "chapter2": "Basics"},
    "book2": {"chapter1": "Getting Started", "chapter2": "Advanced Topics"}
}
book_id = "book1"
# Access chapter2 title of the selected book and assign it to chapter_title
# Your code here

Hint

Use two square brackets to access nested dictionaries: first for book, second for chapter.

4

Print the chapter title

Write a print statement to display the value of chapter_title.

Rest API

library = {
    "book1": {"chapter1": "Introduction", "chapter2": "Basics"},
    "book2": {"chapter1": "Getting Started", "chapter2": "Advanced Topics"}
}
book_id = "book1"
chapter_title = library[book_id]["chapter2"]
# Print the chapter_title
# Your code here

Hint

Use print() to show the chapter title on the screen.

Practice

1. What does a hierarchical resource path in a REST API represent?

easy

A. A nested structure showing relationships between resources

B. A random list of unrelated resources

C. A single resource without any relation

D. A method to encrypt API data

Solution

1. Step 1: Understand resource organization

   Hierarchical paths show how resources are connected, like folders inside folders.

2. Step 2: Identify the purpose of hierarchical paths

   They help represent parent-child relationships clearly in the API URL.

3. Final Answer:

   A nested structure showing relationships between resources -> Option A

4. Quick Check:

   Hierarchical paths = nested resource relationships [OK]

Hint: Think of folders inside folders to understand hierarchy [OK]

Common Mistakes:

• Confusing hierarchy with unrelated resource lists
• Ignoring the relationship between resources
• Thinking it's about data encryption

2. Which of the following is the correct syntax for a hierarchical resource path to access comments of a post with ID 10?

easy

A. /posts/10/comments

B. /comments/posts/10

C. /posts/comments/10

D. /10/posts/comments

Solution

1. Step 1: Identify the parent resource and its ID

   The parent resource is 'posts' with ID 10, so it comes first in the path.

2. Step 2: Append the child resource

   Comments belong to the post, so '/comments' follows '/posts/10'.

3. Final Answer:

   /posts/10/comments -> Option A

4. Quick Check:

   Parent resource + ID + child resource = /posts/10/comments [OK]

Hint: Parent resource and ID come before child resource [OK]

Common Mistakes:

• Placing child resource before parent
• Swapping resource names and IDs
• Using incorrect order of segments

3. Given the REST API path /users/5/orders/12/items, what resource does this path represent?

medium

A. All orders of all users

B. Order 12 of user 5

C. User 5's profile information

D. Items in order 12 of user 5

Solution

1. Step 1: Break down the path segments

   /users/5 means user with ID 5, /orders/12 means order with ID 12 for that user, and /items means the items in that order.

2. Step 2: Understand the full resource

   The path points to the items inside order 12 which belongs to user 5.

3. Final Answer:

   Items in order 12 of user 5 -> Option D

4. Quick Check:

   Path shows nested resources = items in order 12 of user 5 [OK]

Hint: Read path left to right as parent to child resources [OK]

Common Mistakes:

• Ignoring the nested order and item relationship
• Confusing order with user profile
• Assuming it lists all users or orders

4. Identify the error in this hierarchical REST API path: /projects//tasks/7

medium

A. Missing task ID before 7

B. Double slash between 'projects' and 'tasks' is invalid

C. Resource names should be capitalized

D. The path should end with a slash

Solution

1. Step 1: Check the path syntax

   The path has two slashes '//' between 'projects' and 'tasks', which is not valid in REST API paths.

2. Step 2: Understand correct path format

   Only one slash should separate resource names and IDs to maintain proper hierarchy.

3. Final Answer:

   Double slash between 'projects' and 'tasks' is invalid -> Option B

4. Quick Check:

   Only single slashes separate path segments [OK]

Hint: Check for extra or missing slashes in paths [OK]

Common Mistakes:

• Ignoring double slashes as harmless
• Thinking resource names must be capitalized
• Believing trailing slash is mandatory

5. You want to design a REST API path to access all reviews for a specific product variant. The product ID is 20 and the variant ID is 5. Which path correctly represents this hierarchical resource?

hard

A. /products/reviews/20/variants/5

B. /reviews/products/20/variants/5

C. /products/20/variants/5/reviews

D. /variants/5/products/20/reviews

Solution

1. Step 1: Identify the resource hierarchy

   Reviews belong to a variant, which belongs to a product. So the path should start with product ID, then variant ID, then reviews.

2. Step 2: Construct the path in correct order

   The correct order is /products/20/variants/5/reviews to show this nested relationship clearly.

3. Final Answer:

   /products/20/variants/5/reviews -> Option C

4. Quick Check:

   Parent to child order: product -> variant -> reviews [OK]

Hint: Order path segments from general to specific resource [OK]

Common Mistakes:

• Placing reviews before products or variants
• Mixing order of product and variant IDs
• Using unrelated resource order