REST constraints and principles in Rest API - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to identify the REST constraint that requires each request to contain all information needed to understand it.

Rest API

The REST constraint that requires each request to contain all necessary information is called [1].

Drag options to blanks, or click blank then click option'

AStatelessness

BCacheability

CLayered System

DUniform Interface

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing statelessness with cacheability.

Thinking that the server keeps track of client state.

The Statelessness constraint means that each request from client to server must contain all the information needed to understand and process the request.

2fill in blank

medium

Complete the code to name the REST principle that defines a fixed set of operations like GET, POST, PUT, DELETE.

Rest API

The REST principle that defines a fixed set of operations is called [1].

Drag options to blanks, or click blank then click option'

ACacheability

BStatelessness

CUniform Interface

DLayered System

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up uniform interface with statelessness.

Thinking it refers to caching behavior.

The Uniform Interface principle defines a standardized way to communicate between client and server, including a fixed set of operations like GET, POST, PUT, and DELETE.

3fill in blank

hard

Fix the error in the statement about REST constraints: 'The Layered System constraint means clients must know all layers in the system.'

Rest API

The Layered System constraint means clients must [1] all layers in the system.

Drag options to blanks, or click blank then click option'

Aknow

Bignore

Cbypass

Dcontrol

Attempts:

3 left

💡 Hint

Common Mistakes

Assuming clients must know all layers.

Confusing layered system with uniform interface.

The Layered System constraint means clients do not need to know or be aware of all layers in the system. Layers can be added or removed without affecting the client.

4fill in blank

hard

Complete the code to identify the REST constraint that allows responses to be cached and reused.

Rest API

The REST constraint called [1] allows responses to be cached and reused.

Drag options to blanks, or click blank then click option'

AUniform Interface

BStatelessness

CLayered System

DCacheability

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing cacheability with statelessness.

Thinking caching is not part of REST constraints.

Cacheability means responses can be stored (cached) and reused for later requests to improve performance and scalability.

5fill in blank

hard

Fill all three blanks to complete the REST principle that uses hypermedia to guide client interactions.

Rest API

The REST principle called [1] uses [2] as the engine of [3] state.

Drag options to blanks, or click blank then click option'

AUniform Interface

BHypermedia

CApplication

DStatelessness

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up hypermedia with caching.

Not understanding application state driven by hypermedia.

The Uniform Interface principle includes the concept of Hypermedia as the engine of Application state, meaning clients navigate the API dynamically by following links provided in responses.

Practice

1. Which of the following is a key constraint of REST that ensures each request from client to server must contain all the information needed to understand and process the request?

easy

A. Cacheability

B. Layered System

C. Statelessness

D. Code on Demand

Solution

1. Step 1: Understand the meaning of statelessness in REST

   Statelessness means the server does not store any client context between requests. Each request must be self-contained.

2. Step 2: Match the constraint to the description

   The description says each request must have all needed info, which matches statelessness.

3. Final Answer:

   Statelessness -> Option C

4. Quick Check:

   Request self-contained = Statelessness [OK]

Hint: Requests must be independent and self-contained [OK]

Common Mistakes:

• Confusing cacheability with statelessness
• Thinking layered system means stateless
• Assuming code on demand is required

2. Which HTTP method is NOT considered safe and idempotent according to REST principles?

easy

A. POST

B. PUT

C. GET

D. DELETE

Solution

1. Step 1: Recall safe and idempotent HTTP methods

   GET, PUT, and DELETE are idempotent; GET is safe. POST is neither safe nor idempotent.

2. Step 2: Identify the method that is not safe and idempotent

   POST changes server state and can create multiple resources, so it is not idempotent or safe.

3. Final Answer:

   POST -> Option A

4. Quick Check:

   POST is not safe or idempotent [OK]

Hint: POST changes data and is not idempotent [OK]

Common Mistakes:

• Thinking PUT is unsafe
• Confusing DELETE as unsafe
• Assuming GET modifies data

3. Given the following REST API response headers, which constraint is being applied?

Cache-Control: max-age=3600
ETag: "abc123"

medium

A. Cacheability

B. Uniform Interface

C. Statelessness

D. Client-Server

Solution

1. Step 1: Analyze the headers Cache-Control and ETag

   Cache-Control and ETag headers control how responses are cached by clients or intermediaries.

2. Step 2: Identify the REST constraint related to caching

   Cacheability means responses can be stored and reused to improve performance.

3. Final Answer:

   Cacheability -> Option A

4. Quick Check:

   Cache headers = Cacheability [OK]

Hint: Cache headers indicate cacheability constraint [OK]

Common Mistakes:

• Confusing cache headers with statelessness
• Thinking uniform interface relates to headers
• Assuming client-server means caching

4. You have a REST API that stores user sessions on the server between requests. Which REST constraint is violated and how can you fix it?

medium

A. Uniform Interface; change URL structure

B. Cacheability; disable caching on responses

C. Layered System; remove intermediaries

D. Statelessness; move session data to client or include in each request

Solution

1. Step 1: Identify the violated constraint

   Storing session data on server between requests breaks statelessness because server keeps client state.

2. Step 2: Suggest a fix to restore statelessness

   Move session info to client (like tokens) or send all needed info in each request.

3. Final Answer:

   Statelessness; move session data to client or include in each request -> Option D

4. Quick Check:

   Server session storage breaks statelessness [OK]

Hint: No server session storage means statelessness [OK]

Common Mistakes:

• Confusing cacheability with session storage
• Thinking layered system relates to sessions
• Trying to fix by changing URLs

5. You want to design a REST API that allows clients to update user profiles partially without sending the entire profile data. Which HTTP method and REST principle best support this requirement?

hard

A. PUT method and Uniform Interface constraint

B. PATCH method and Uniform Interface constraint

C. POST method and Statelessness constraint

D. DELETE method and Cacheability constraint

Solution

1. Step 1: Identify the HTTP method for partial updates

   PATCH is designed for partial updates, unlike PUT which replaces entire resource.

2. Step 2: Connect the method to the REST principle

   Uniform Interface means using standard methods consistently; PATCH fits this principle for partial updates.

3. Final Answer:

   PATCH method and Uniform Interface constraint -> Option B

4. Quick Check:

   Partial update = PATCH + Uniform Interface [OK]

Hint: Partial update uses PATCH and uniform interface [OK]

Common Mistakes:

• Using PUT for partial updates
• Confusing POST with PATCH
• Linking DELETE to updates