Resource collections in Laravel - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this Laravel resource collection?

Given the following Laravel resource collection code, what will be the JSON output when returning UserResource::collection($users) where $users contains two users with names 'Alice' and 'Bob'?

Laravel

<?php

namespace App\Http\Resources;

use Illuminate\Http\Resources\Json\JsonResource;

class UserResource extends JsonResource
{
    public function toArray($request)
    {
        return [
            'username' => $this->name,
            'email' => $this->email
        ];
    }
}

// Controller method
public function index()
{
    $users = User::all();
    return UserResource::collection($users);
}

A {"data":[{"username":"Alice","email":"[e-mail]"},{"username":"Bob","email":"[e-mail]"}]}

B [{"username":"Alice","email":"[e-mail]"},{"username":"Bob","email":"[e-mail]"}]

C {"users":[{"name":"Alice","email":"[e-mail]"},{"name":"Bob","email":"[e-mail]"}]}

D {"data":{"username":"Alice","email":"[e-mail]"}}

💡 Hint

Remember that Laravel resource collections wrap the array of resources inside a 'data' key by default.

Laravel resource collections automatically wrap the array of transformed resources inside a data key. Each user is transformed using the UserResource toArray method, which returns username and email keys.

📝 Syntax

intermediate

Which option causes a syntax error in Laravel resource collection usage?

Identify which code snippet will cause a syntax error when returning a resource collection in Laravel.

A return new UserResource::collection($users);

B return UserResource::collection($users)->response();

C return UserResource::collection($users);

D return UserResource::collection($users)->toResponse($request);

💡 Hint

Check how the 'new' keyword is used with static methods.

The collection method is a static method and should not be called with the new keyword. Option A incorrectly uses new with a static method call, causing a syntax error.

❓ state_output

advanced

What is the value of the 'meta' key in this resource collection response?

Consider this Laravel resource collection with added meta data:

return UserResource::collection($users)->additional(['meta' => ['total_users' => $users->count()]]);

What will be the value of the 'meta' key in the JSON response?

A [{"total_users":2}]

B {"total_users":2}

C {"count":2}

D null

💡 Hint

The additional method adds extra data at the root level of the JSON response.

The additional method adds extra data to the resource response. Here, it adds a meta key with an array containing total_users equal to the count of users.

🔧 Debug

advanced

Why does this resource collection return an empty 'data' array?

Given this controller code:

public function index() {
    $users = User::where('active', true)->get();
    return UserResource::collection($users);
}

But the JSON response shows {"data":[]} even though there are active users in the database. What is the most likely cause?

A The UserResource's toArray method returns an empty array.

B The User model does not have an 'active' attribute.

C The controller forgot to import the UserResource class.

D The $users variable is empty because the query is incorrect.

💡 Hint

Consider why the query might not return the expected users.

The response shows an empty 'data' array, indicating that $users is an empty collection. Even though active users exist, the query where('active', true) is likely incorrect (e.g., the column might be named 'is_active'), so no records match.

🧠 Conceptual

expert

Which statement about Laravel resource collections is TRUE?

Select the correct statement about Laravel resource collections.

A Resource collections automatically paginate the data without extra code.

B Resource collections require manual looping over each model to transform data.

C Resource collections wrap the transformed data inside a 'data' key by default.

D Resource collections cannot add extra meta data to the response.

💡 Hint

Think about the default JSON structure of resource collections.

By default, Laravel resource collections wrap the array of transformed resources inside a data key. Pagination requires explicit use of pagination methods. Meta data can be added with the additional method. Manual looping is handled internally by the collection.