Resource expansion (embed related data) in Rest API - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to request expanded user data with embedded posts.

Rest API

GET /users/123?[1]=expand

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

Aexpand

Bembed

Cinclude

Dattach

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'embed' or 'include' which might not be supported by the API.

Forgetting to add the query parameter.

The query parameter expand is commonly used to request related resources embedded in the response.

2fill in blank

medium

Complete the code to embed comments when fetching posts.

Rest API

GET /posts?[1]=embed

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

Aexpand

Binclude

Cfields

Dembed

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'expand' which might not work for this API.

Using 'fields' which is for selecting fields, not embedding.

The embed parameter is used here to include related comments inside each post.

3fill in blank

hard

Fix the error in the URL to correctly expand the 'author' data for each comment.

Rest API

GET /comments?expand=[1]

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

Ausers

Bauthor

Cuser

Dauthors

Attempts:

3 left

💡 Hint

Common Mistakes

Using plural form 'authors' which causes an error.

Using 'user' or 'users' which are incorrect resource names.

The related resource is singular author, matching the API's expected parameter.

4fill in blank

hard

Fill both blanks to embed 'profile' and 'settings' data when fetching users.

Rest API

GET /users?[1]=embed&[2]=include

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

Aembed

Bexpand

Cinclude

Dfields

Attempts:

3 left

💡 Hint

Common Mistakes

Using the same parameter twice.

Using 'fields' which is for selecting fields, not embedding.

Use embed and include parameters to request related data embedded in the response.

5fill in blank

hard

Fill all three blanks to select 'orders', embed 'items', and include 'shipping' data in a single request.

Rest API

GET /customers/456?[1]=fields&[2]=embed&[3]=include

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

Aexpand

Bembed

Cinclude

Dfields

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'expand' for all parameters which may cause errors.

Mixing up 'embed' and 'include' parameters.

Use fields to select fields, embed to embed related items, and include to include shipping data.

Practice

1. What is the main purpose of using the expand parameter in a REST API request?

easy

A. To delete related resources automatically

B. To include related resource data within the main resource response

C. To paginate the results of the API response

D. To filter the main resource by specific fields

Solution

1. Step 1: Understand the expand parameter role

   The expand parameter is used to include related or nested resource data inside the main resource response.

2. Step 2: Compare with other options

   Filtering, pagination, and deletion are different API features and not related to embedding data.

3. Final Answer:

   To include related resource data within the main resource response -> Option B

4. Quick Check:

   Expand = embed related data [OK]

Hint: Expand means embed related data inside main response [OK]

Common Mistakes:

• Confusing expand with filtering or pagination
• Thinking expand deletes data
• Assuming expand changes data instead of embedding

2. Which of the following is the correct syntax to expand the 'author' field in a REST API GET request URL?

easy

A. /posts?expand=author

B. /posts?embed=author

C. /posts?include=author

D. /posts?fields=author

Solution

1. Step 1: Identify the standard parameter for resource expansion

   The common parameter to embed related data is expand.

2. Step 2: Check the URL syntax

   The correct syntax uses ?expand=author to embed the author data inside posts.

3. Final Answer:

   /posts?expand=author -> Option A

4. Quick Check:

   Use expand=field to embed [OK]

Hint: Use ?expand=resourceName to embed related data [OK]

Common Mistakes:

• Using embed or include instead of expand
• Using fields which filters fields, not expands
• Missing the question mark before parameters

3. Given the API endpoint /orders?expand=customer, what will the response include?

medium

A. A list of customers unrelated to orders

B. Only order details without customer info

C. Only customer information without orders

D. Order details with embedded customer information

Solution

1. Step 1: Analyze the expand parameter usage

   The parameter expand=customer tells the API to include customer data inside each order.

2. Step 2: Understand the response content

   The response will contain order details plus the related customer information embedded.

3. Final Answer:

   Order details with embedded customer information -> Option D

4. Quick Check:

   Expand=customer means embed customer data [OK]

Hint: Expand embeds related resource data inside main response [OK]

Common Mistakes:

• Expecting only orders without customer info
• Thinking expand replaces main resource
• Confusing expand with filtering or unrelated data

4. You tried to expand the 'comments' field with /posts?expand=comments but the API returns an error. What is the most likely cause?

medium

A. The 'comments' field is not a valid expandable resource

B. The API requires POST method for expansion

C. The expand parameter should be 'include' instead

D. The URL is missing a trailing slash

Solution

1. Step 1: Check if 'comments' is expandable

   Not all fields can be expanded; the API must support expanding 'comments'.

2. Step 2: Verify HTTP method and parameter correctness

   Expansion usually works with GET and uses 'expand', so POST or 'include' are unlikely causes.

3. Step 3: URL format check

   Missing trailing slash usually does not cause expansion errors.

4. Final Answer:

   The 'comments' field is not a valid expandable resource -> Option A

5. Quick Check:

   Expandable fields must be supported by API [OK]

Hint: Check if field supports expand before using it [OK]

Common Mistakes:

• Using wrong HTTP method for expansion
• Confusing expand with include parameter
• Assuming all fields are expandable

5. You want to get a list of invoices with embedded customer and payment details in one API call. Which URL correctly uses resource expansion for both related resources?

hard

A. /invoices?embed=customer,payment

B. /invoices?expand=customer&expand=payment

C. /invoices?expand=customer,payment

D. /invoices?expand=customer;payment

Solution

1. Step 1: Understand how to expand multiple resources

   Multiple expansions are usually comma-separated in a single expand parameter.

2. Step 2: Evaluate each option's syntax

   /invoices?expand=customer,payment uses comma-separated values correctly. /invoices?expand=customer&expand=payment repeats the parameter which is often unsupported. /invoices?embed=customer,payment uses 'embed' which is incorrect. /invoices?expand=customer;payment uses semicolon which is not standard.

3. Final Answer:

   /invoices?expand=customer,payment -> Option C

4. Quick Check:

   Multiple expands separated by commas [OK]

Hint: Use commas to expand multiple resources in one parameter [OK]

Common Mistakes:

• Repeating expand parameter multiple times
• Using embed instead of expand
• Separating resources with semicolons