Creating middleware in Laravel - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a middleware class in Laravel.

Laravel

class CheckAge {
    public function handle($request, Closure [1]) {
        // middleware logic
    }
}

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

Aresponse

Brequest

Cnext

Dmiddleware

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'request' as the second parameter instead of 'next'.

Omitting the Closure parameter.

The handle method receives the request and a Closure called next to pass the request further.

2fill in blank

medium

Complete the code to allow the request to proceed in the middleware.

Laravel

public function handle($request, Closure $next) {
    return [1]($request);
}

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

A$request

B$next

Cnext

Dhandle

Attempts:

3 left

💡 Hint

Common Mistakes

Returning $request directly instead of calling $next.

Calling a function named 'next' without the $ sign.

You must call the Closure $next with the $request to pass the request to the next middleware or controller.

3fill in blank

hard

Fix the error in the middleware to block users under 18 years old.

Laravel

public function handle($request, Closure $next) {
    if ($request->age [1] 18) {
        return redirect('home');
    }
    return $next($request);
}

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

A<

B>=

C==

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>=' which allows underage users.

Using '==' which only blocks exactly 18.

To block users under 18, check if age is less than 18.

4fill in blank

hard

Fill both blanks to create middleware that adds a header and passes the request.

Laravel

public function handle($request, Closure [1]) {
    $response = [2]($request);
    $response->headers->set('X-Custom-Header', 'MyValue');
    return $response;
}

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

A$next

Bnext

C$response

Dhandle

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'next' without $ sign.

Using $response as the Closure parameter.

The Closure parameter is $next and you call $next($request) to get the response.

5fill in blank

hard

Fill all three blanks to create middleware that checks a user role and redirects if unauthorized.

Laravel

public function handle($request, Closure [1]) {
    if ($request->user()->role [2] 'admin') {
        return [3]($request);
    }
    return redirect('unauthorized');
}

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

A$next

B!=

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' instead of '!=' to block unauthorized users.

Calling 'next' without $ sign.

The Closure parameter is $next, check if role is not equal 'admin', then call $next($request).

Practice

1. What is the primary purpose of middleware in Laravel?

easy

A. To define routes for the application

B. To filter and modify HTTP requests before they reach the controller

C. To create database migrations automatically

D. To generate views for the user interface

Solution

1. Step 1: Understand middleware role

   Middleware acts as a filter that processes HTTP requests before they reach the controller or after the response leaves the controller.

2. Step 2: Identify correct purpose

   Among the options, only filtering and modifying HTTP requests matches middleware's role.

3. Final Answer:

   To filter and modify HTTP requests before they reach the controller -> Option B

4. Quick Check:

   Middleware filters requests [OK]

Hint: Middleware filters requests before controllers [OK]

Common Mistakes:

• Confusing middleware with routing
• Thinking middleware creates database migrations
• Assuming middleware generates views

2. Which command correctly creates a new middleware named CheckAge in Laravel?

easy

A. php artisan make:middleware CheckAge

B. php artisan create:middleware CheckAge

C. php artisan middleware:create CheckAge

D. php artisan generate:middleware CheckAge

Solution

1. Step 1: Recall Laravel artisan command for middleware

   The correct command to create middleware is php artisan make:middleware Name.

2. Step 2: Match the command with options

   Only php artisan make:middleware CheckAge uses the exact correct syntax.

3. Final Answer:

   php artisan make:middleware CheckAge -> Option A

4. Quick Check:

   Use 'make:middleware' to create middleware [OK]

Hint: Use 'make:middleware' with artisan to create middleware [OK]

Common Mistakes:

• Using 'create:middleware' instead of 'make:middleware'
• Mixing command order or keywords
• Forgetting to specify middleware name

3. Given this middleware handle method, what will happen if the user is not authenticated?

public function handle($request, Closure $next) {
    if (!auth()->check()) {
        return redirect('login');
    }
    return $next($request);
}

medium

A. The request proceeds to the next middleware or controller

B. The request is blocked with a 403 Forbidden response

C. An error is thrown because of missing return

D. The user is redirected to the login page

Solution

1. Step 1: Analyze the authentication check

   The code checks if the user is not authenticated using !auth()->check().

2. Step 2: Understand the redirect action

   If not authenticated, it returns a redirect response to 'login', stopping further request processing.

3. Final Answer:

   The user is redirected to the login page -> Option D

4. Quick Check:

   Unauthenticated users get redirected [OK]

Hint: Redirect happens if auth check fails [OK]

Common Mistakes:

• Assuming request proceeds despite failed auth
• Thinking an error is thrown
• Confusing redirect with 403 response

4. Identify the error in this middleware handle method:

public function handle($request, Closure $next) {
    if ($request->user()->role !== 'admin') {
        abort(403, 'Unauthorized');
    }
}

medium

A. No error, this middleware is correct

B. Incorrect method name, should be handleRequest

C. Missing return statement for $next middleware call

D. Using abort() is not allowed in middleware

Solution

1. Step 1: Check middleware handle method structure

   Middleware must return either a response or call $next($request) to continue the request.

2. Step 2: Identify missing return

   This code aborts if role is not admin but does not return $next($request) if the user is admin, causing no response to be returned.

3. Final Answer:

   Missing return statement for $next middleware call -> Option C

4. Quick Check:

   Always return $next($request) to continue [OK]

Hint: Always return $next($request) in middleware [OK]

Common Mistakes:

• Forgetting to return $next($request)
• Thinking abort() is disallowed
• Renaming handle method incorrectly

5. You want to create middleware that blocks requests with a query parameter blocked=true by aborting with a 403 Forbidden response. Which handle method implementation correctly achieves this?

hard

A. public function handle($request, Closure $next) {
if ($request->query('blocked') === 'true') {
abort(403, 'Access denied');
}
return $next($request);
}

B. public function handle($request, Closure $next) {
if ($request->input('blocked') == true) {
return redirect('home');
}
return $next($request);
}

C. public function handle($request, Closure $next) {
if ($request->blocked === true) {
abort(404);
}
return $next($request);
}

D. public function handle($request, Closure $next) {
if ($request->has('blocked')) {
return response('Blocked', 401);
}
return $next($request);
}

Solution

1. Step 1: Check how to read query parameters

   Use $request->query('blocked') to get the query parameter value as string.

2. Step 2: Verify condition and response

   public function handle($request, Closure $next) { if ($request->query('blocked') === 'true') { abort(403, 'Access denied'); } return $next($request); } checks if 'blocked' equals string 'true' and aborts with 403, then returns next middleware call.

3. Step 3: Compare other options

   public function handle($request, Closure $next) { if ($request->input('blocked') == true) { return redirect('home'); } return $next($request); } uses input() and redirects instead of aborting; public function handle($request, Closure $next) { if ($request->blocked === true) { abort(404); } return $next($request); } accesses property incorrectly; public function handle($request, Closure $next) { if ($request->has('blocked')) { return response('Blocked', 401); } return $next($request); } returns 401 but blocks any 'blocked' param regardless of value.

4. Final Answer:

   Checks $request->query('blocked') === 'true' and uses abort(403, 'Access denied') -> Option A

5. Quick Check:

   Use $request->query('blocked') and abort(403) [OK]

Hint: Use $request->query('param') and abort(403) to block [OK]

Common Mistakes:

• Using $request->blocked instead of query()
• Returning redirect instead of abort
• Not checking exact 'true' string value