Single action controllers in Laravel - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a single action controller class in Laravel.

Laravel

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class WelcomeController extends Controller
{
    public function [1](Request $request)
    {
        return view('welcome');
    }
}

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

A__invoke

Bhandle

Cindex

Dshow

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'handle' or 'index' instead of '__invoke' for single action controllers.

In Laravel, a single action controller uses the __invoke method to handle requests.

2fill in blank

medium

Complete the route definition to use a single action controller in Laravel.

Laravel

use App\Http\Controllers\WelcomeController;

Route::get('/', [1]::class);

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

AWelcomeController

BWelcomeController@index

CWelcomeController@handle

DWelcomeController@__invoke

Attempts:

3 left

💡 Hint

Common Mistakes

Adding '@__invoke' or other method names in the route for single action controllers.

When using a single action controller, you pass the controller class name directly to the route.

3fill in blank

hard

Fix the error in the single action controller method signature.

Laravel

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class ContactController extends Controller
{
    public function [1](Request $request, $id)
    {
        return view('contact', ['id' => $id]);
    }
}

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

Ahandle

Bindex

C__invoke

Dshow

Attempts:

3 left

💡 Hint

Common Mistakes

Using method names other than '__invoke' in single action controllers.

The __invoke method can accept parameters like $id if needed for single action controllers.

4fill in blank

hard

Fill both blanks to create a route that uses a single action controller with middleware.

Laravel

use App\Http\Controllers\DashboardController;

Route::get('/dashboard', [1]::class)->[2]('auth');

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

ADashboardController

Bmiddleware

Cauth

Dhandle

Attempts:

3 left

💡 Hint

Common Mistakes

Using method names like 'handle' instead of 'middleware' for applying middleware.

The route uses the controller class name and the middleware method to apply middleware.

5fill in blank

hard

Fill all three blanks to define a single action controller class with a constructor and the invoke method.

Laravel

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class ProfileController extends Controller
{
    private $service;

    public function [1](UserService $service)
    {
        $this->service = [2];
    }

    public function [3](Request $request)
    {
        return view('profile', ['data' => $this->service->getProfile()]);
    }
}

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

A__construct

B$service

C__invoke

Dhandle

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong method names like 'handle' instead of '__invoke' for the single action method.

Not assigning the constructor parameter correctly.

The constructor is named __construct, it assigns the passed $service to the property, and the single action method is __invoke.

Practice

1. What is the main purpose of a single action controller in Laravel?

easy

A. To replace middleware functionality

B. To manage multiple actions in one controller

C. To handle exactly one action using the __invoke method

D. To handle database migrations

Solution

1. Step 1: Understand the role of single action controllers

   Single action controllers are designed to handle only one action, making code simpler and focused.

2. Step 2: Identify the method used

   They use the special __invoke method to handle that single action.

3. Final Answer:

   To handle exactly one action using the __invoke method -> Option C

4. Quick Check:

   Single action controller = __invoke method [OK]

Hint: Single action controllers always use __invoke method [OK]

Common Mistakes:

• Thinking they handle multiple actions
• Confusing with middleware or migrations
• Assuming they require multiple methods

2. Which of the following is the correct syntax to define a single action controller in Laravel?

easy

A. class MyController { public function __invoke() {} }

B. class MyController { public function handle() {} }

C. class MyController { public function index() {} }

D. class MyController { public function action() {} }

Solution

1. Step 1: Recall the special method for single action controllers

   Single action controllers use the __invoke() method to handle the action.

2. Step 2: Match the syntax

   The correct syntax defines a class with a public function __invoke() method.

3. Final Answer:

   class MyController { public function __invoke() {} } -> Option A

4. Quick Check:

   __invoke method syntax = class MyController { public function __invoke() {} } [OK]

Hint: Look for __invoke method in the class [OK]

Common Mistakes:

• Using index() or handle() instead of __invoke()
• Forgetting the public visibility
• Confusing method names with other controller types

3. Given this single action controller code, what will be the output when accessed?

class WelcomeController {
    public function __invoke() {
        return 'Hello, Laravel!';
    }
}

medium

A. Hello, Laravel!

B. Error: Method not found

C. Empty response

D. 404 Not Found

Solution

1. Step 1: Understand __invoke method behavior

   The __invoke method runs when the controller is called as a single action, returning the string 'Hello, Laravel!'.

2. Step 2: Predict the output

   Since the method returns a string, the response will be that string displayed.

3. Final Answer:

   Hello, Laravel! -> Option A

4. Quick Check:

   __invoke returns string = 'Hello, Laravel!' [OK]

Hint: __invoke returns output directly as response [OK]

Common Mistakes:

• Expecting an error due to missing method name
• Thinking it returns empty or 404
• Confusing with multi-method controllers

4. Identify the error in this single action controller code:

class TestController {
    public function invoke() {
        return 'Test';
    }
}

medium

A. Return statement is invalid

B. Method should be private, not public

C. Class name must be TestActionController

D. Missing __invoke method name with double underscores

Solution

1. Step 1: Check method name for single action controller

   The method must be named __invoke with two underscores, not invoke.

2. Step 2: Verify method visibility and return

   Method should be public and return a value, which is correct here.

3. Final Answer:

   Missing __invoke method name with double underscores -> Option D

4. Quick Check:

   Method name must be __invoke [OK]

Hint: Method must be named __invoke with double underscores [OK]

Common Mistakes:

• Using invoke instead of __invoke
• Changing method visibility incorrectly
• Assuming class name affects single action controller

5. You want to create a single action controller that returns a JSON response with a message 'Success'. Which code snippet correctly implements this?

hard

A. class JsonResponseController {
public function __invoke() {
return json_encode(['message' => 'Success']);
}
}

B. class JsonResponseController {
public function __invoke() {
return response()->json(['message' => 'Success']);
}
}

C. class JsonResponseController {
private function __invoke() {
return ['message' => 'Success'];
}
}

D. class JsonResponseController {
public function handle() {
return json(['message' => 'Success']);
}
}

Solution

1. Step 1: Use __invoke method for single action controller

   The controller must have a public __invoke() method to be a single action controller.

2. Step 2: Return a proper JSON response in Laravel

   Use Laravel's response()->json() helper to return a JSON response correctly.

3. Final Answer:

   class JsonResponseController { public function __invoke() { return response()->json(['message' => 'Success']); } } -> Option B

4. Quick Check:

   __invoke + response()->json() = class JsonResponseController { public function __invoke() { return response()->json(['message' => 'Success']); } } [OK]

Hint: Use response()->json() inside __invoke method [OK]

Common Mistakes:

• Using handle() instead of __invoke()
• Returning raw arrays without response helper
• Using json() function which doesn't exist in Laravel