Controller middleware in Laravel - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to apply middleware to a controller method.

Laravel

public function __construct()
{
    $this->middleware('[1]');
}

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

Aauth

Broute

Cview

Dcache

Attempts:

3 left

💡 Hint

Common Mistakes

Using middleware names that do not exist like 'route' or 'view'.

Forgetting to put the middleware name as a string.

The auth middleware is commonly used to restrict access to authenticated users in Laravel controllers.

2fill in blank

medium

Complete the code to apply middleware only to the 'show' method.

Laravel

public function __construct()
{
    $this->middleware('auth')->only('[1]');
}

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

Ashow

Bindex

Cedit

Dcreate

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing methods like 'index' or 'create' which are for listing or creating resources.

Not using quotes around the method name.

The only method limits middleware to specified controller methods. Here, it applies only to the 'show' method.

3fill in blank

hard

Fix the error in applying middleware to exclude the 'index' method.

Laravel

public function __construct()
{
    $this->middleware('auth')->except('[1]');
}

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

Aedit

Bindex

Cshow

Ddestroy

Attempts:

3 left

💡 Hint

Common Mistakes

Excluding the wrong method like 'show' or 'edit'.

Not using quotes around the method name.

The except method excludes the specified method from middleware. To exclude the 'index' method, use 'index'.

4fill in blank

hard

Fill both blanks to apply 'auth' middleware only to 'edit' and 'update' methods.

Laravel

public function __construct()
{
    $this->middleware('[1]')->only('[2]', 'update');
}

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

Aauth

Bguest

Cedit

Dshow

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'guest' middleware which is for unauthenticated users.

Using wrong method names like 'show' instead of 'edit'.

The 'auth' middleware restricts access to authenticated users. Using only('edit', 'update') applies it to those methods.

5fill in blank

hard

Fill all three blanks to apply 'throttle' middleware with limit '60,1' except for 'index' and 'show' methods.

Laravel

public function __construct()
{
    $this->middleware('[1]:[2]')->except('[3]', 'show');
}

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

Athrottle

B60,1

Cindex

Dguest

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'auth' or 'guest' instead of 'throttle' for rate limiting.

Incorrect method names in except list.

The 'throttle' middleware limits request rate. Here, '60,1' means 60 requests per minute. The except excludes 'index' and 'show' methods.

Practice

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

easy

A. To connect the controller to the database

B. To define routes for the controller

C. To run code before or after controller methods for access control or modification

D. To create views for the controller

Solution

1. Step 1: Understand middleware role

   Middleware acts as a filter that runs before or after controller methods to control access or modify requests/responses.

2. Step 2: Differentiate from other controller tasks

   Defining routes, connecting to databases, or creating views are not middleware responsibilities.

3. Final Answer:

   To run code before or after controller methods for access control or modification -> Option C

4. Quick Check:

   Middleware controls access and actions around controller methods = A [OK]

Hint: Middleware filters requests before/after controller methods [OK]

Common Mistakes:

• Confusing middleware with routing
• Thinking middleware creates views
• Assuming middleware connects to database

2. Which is the correct way to add middleware to a Laravel controller constructor?

easy

A. $this->middleware('auth');

B. middleware->add('auth');

C. addMiddleware('auth');

D. useMiddleware('auth');

Solution

1. Step 1: Recall Laravel middleware syntax

   In Laravel controllers, middleware is added inside the constructor using $this->middleware('name');.

2. Step 2: Check other options for syntax correctness

   Options A, C, and D do not follow Laravel's middleware syntax and will cause errors.

3. Final Answer:

   $this->middleware('auth'); -> Option A

4. Quick Check:

   Use $this->middleware() in constructor = B [OK]

Hint: Use $this->middleware('name') inside constructor [OK]

Common Mistakes:

• Using incorrect method names
• Calling middleware outside constructor
• Missing $this keyword

3. Given this controller constructor code:

public function __construct() {
    $this->middleware('auth')->only('edit', 'update');
}

Which methods will have the 'auth' middleware applied?

medium

A. Only the edit and update methods

B. All methods except edit and update

C. All methods in the controller

D. No methods, syntax error

Solution

1. Step 1: Understand the use of only() method

   The only('edit', 'update') limits middleware to run only on these two methods.

2. Step 2: Confirm middleware application

   Middleware 'auth' applies only to 'edit' and 'update', other methods are unaffected.

3. Final Answer:

   Only the edit and update methods -> Option A

4. Quick Check:

   only() limits middleware to specified methods = D [OK]

Hint: only() applies middleware to listed methods only [OK]

Common Mistakes:

• Confusing only() with except()
• Assuming middleware applies to all methods
• Thinking syntax causes error

4. Identify the error in this controller constructor:

public function __construct() {
    $this->middleware('auth')->except('index', 'show');
    $this->middleware('log');
}

medium

A. Middleware 'log' will override 'auth' middleware

B. You cannot call middleware twice in constructor

C. except() method requires array, not multiple arguments

D. No error; both middleware apply correctly

Solution

1. Step 1: Check multiple middleware calls

   Laravel allows multiple middleware calls in constructor; they stack and apply in order.

2. Step 2: Validate except() usage

   except() accepts multiple string arguments or an array; both are valid.

3. Final Answer:

   No error; both middleware apply correctly -> Option D

4. Quick Check:

   Multiple middleware calls and except() usage are valid = C [OK]

Hint: Multiple middleware calls stack; except() accepts multiple args [OK]

Common Mistakes:

• Thinking multiple middleware calls override each other
• Assuming except() needs array only
• Believing syntax causes error

5. You want to apply the 'verified' middleware to all controller methods except 'index' and 'show', and also apply 'log' middleware only to 'store' and 'update'. Which constructor code correctly implements this using arrays?

hard

A. public function __construct() {
$this->middleware('verified')->only('index', 'show');
$this->middleware('log')->except('store', 'update');
}

B. public function __construct() {
$this->middleware('verified')->except(['index', 'show']);
$this->middleware('log')->only(['store', 'update']);
}

C. public function __construct() {
$this->middleware('verified');
$this->middleware('log');
}

D. public function __construct() {
$this->middleware('verified')->except('index', 'show');
$this->middleware('log')->only('store', 'update');
}

Solution

1. Step 1: Apply 'verified' middleware except on 'index' and 'show'

   Use except() with array to exclude 'index' and 'show' from 'verified' middleware.

2. Step 2: Apply 'log' middleware only on 'store' and 'update'

   Use only() with array to limit 'log' middleware to 'store' and 'update' methods.

3. Step 3: Compare options

   public function __construct() { $this->middleware('verified')->except('index', 'show'); $this->middleware('log')->only('store', 'update'); } uses except() and only() with multiple string arguments (valid but less common). public function __construct() { $this->middleware('verified')->except(['index', 'show']); $this->middleware('log')->only(['store', 'update']); } uses arrays which is clearer and recommended. Options B and C do not match requirements.

4. Final Answer:

   public function __construct() { $this->middleware('verified')->except(['index', 'show']); $this->middleware('log')->only(['store', 'update']); } -> Option B

5. Quick Check:

   Use except() and only() with arrays for clarity = A [OK]

Hint: Use except() and only() with arrays for multiple methods [OK]

Common Mistakes:

• Mixing only() and except() incorrectly
• Not using arrays for multiple methods
• Applying middleware to wrong methods