Form request classes in Laravel - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Form Request class in Laravel?

A Form Request class is a special class in Laravel that handles validation and authorization of form data before the controller processes it. It helps keep controllers clean and organizes validation logic.

beginner

How do you create a Form Request class in Laravel?

You create a Form Request class by running the artisan command: <code>php artisan make:request YourRequestName</code>. This generates a class where you define rules and authorization.

beginner

What method do you use to define validation rules in a Form Request class?

You define validation rules inside the rules() method. This method returns an array where keys are form field names and values are validation rules.

intermediate

What is the purpose of the authorize() method in a Form Request class?

The authorize() method determines if the user is allowed to make this request. It returns true to allow or false to deny access.

intermediate

How do you use a Form Request class in a controller method?

You type-hint the Form Request class in the controller method's parameters. Laravel automatically validates the request before running the method. If validation fails, it redirects back with errors.

Which artisan command creates a Form Request class?

A php artisan make:request

B php artisan make:form

C php artisan make:validation

D php artisan make:controller

The correct command is php artisan make:request to create a Form Request class.

Where do you define validation rules in a Form Request class?

A In the <code>rules()</code> method

B In the <code>authorize()</code> method

C In the controller

D In the routes file

Validation rules are defined inside the rules() method of the Form Request class.

What does the authorize() method return to allow a request?

A null

B false

C true

D 1

Returning true from authorize() allows the request to proceed.

What happens if validation fails in a Form Request class?

A The app crashes

B Laravel redirects back with error messages

C The controller method runs anyway

D Nothing happens

If validation fails, Laravel automatically redirects back to the form with error messages.

How do you apply a Form Request class in a controller?

A Use it as a middleware

B Call it manually inside the method

C Register it in routes

D Type-hint it in the controller method parameters

You apply a Form Request by type-hinting it in the controller method parameters.

Explain how a Form Request class helps organize validation in Laravel.

Think about how keeping validation outside the controller helps.

Describe the steps to create and use a Form Request class in a Laravel app.

Start from creation, then how it works in the controller.

Practice

1. What is the main purpose of a Form Request class in Laravel?

easy

A. To define routes for the application

B. To create database migrations automatically

C. To manage user authentication sessions

D. To organize and handle validation rules separately from controllers

Solution

1. Step 1: Understand the role of Form Request classes

   Form Request classes are designed to keep validation rules and authorization logic separate from controller code.

2. Step 2: Identify the main benefit

   This separation helps keep controllers clean and improves code organization and security.

3. Final Answer:

   To organize and handle validation rules separately from controllers -> Option D

4. Quick Check:

   Form Request = Validation organization [OK]

Hint: Form Requests separate validation from controllers [OK]

Common Mistakes:

• Confusing Form Requests with database migrations
• Thinking Form Requests handle authentication
• Assuming Form Requests define routes

2. Which of the following is the correct way to create a Form Request class using Artisan CLI?

easy

A. php artisan create:request UserRequest

B. php artisan make:formrequest UserRequest

C. php artisan make:request UserRequest

D. php artisan generate:form UserRequest

Solution

1. Step 1: Recall the Artisan command for Form Requests

   The correct Artisan command to create a Form Request class is make:request.

2. Step 2: Match the command with the options

   php artisan make:request UserRequest uses php artisan make:request UserRequest, which is the correct syntax.

3. Final Answer:

   php artisan make:request UserRequest -> Option C

4. Quick Check:

   Artisan command for Form Request = make:request [OK]

Hint: Use 'make:request' to create Form Requests [OK]

Common Mistakes:

• Using 'make:formrequest' instead of 'make:request'
• Using 'create:request' which is invalid
• Using 'generate:form' which does not exist

3. Given this Form Request class snippet, what will $request->validated() return if the input is ['name' => 'John', 'age' => 20]?

class UserRequest extends FormRequest {
    public function rules() {
        return [
            'name' => 'required|string',
            'age' => 'required|integer|min:18'
        ];
    }
}

medium

A. {'name' => 'John', 'age' => 20}

B. {'name' => 'John'}

C. ValidationException error

D. Empty array []

Solution

1. Step 1: Check validation rules against input

   The rules require 'name' as a string and 'age' as an integer >= 18. Input has 'name' = 'John' (string) and 'age' = 20 (integer, >=18), so validation passes.

2. Step 2: Understand what validated() returns

   The validated() method returns all input fields that passed validation, so it returns the full input array.

3. Final Answer:

   {'name' => 'John', 'age' => 20} -> Option A

4. Quick Check:

   Valid input returns full validated data [OK]

Hint: Validated returns all fields passing rules [OK]

Common Mistakes:

• Assuming partial data is returned
• Expecting an error when input is valid
• Confusing validated() with all() method

4. Identify the error in this Form Request class that causes validation to always pass even with invalid input:

class ProductRequest extends FormRequest {
    public function rules() {
        return [
            'price' => 'required|numeric|min:0'
        ];
    }

    public function authorize() {
        return false;
    }
}

medium

A. The authorize method returns false, blocking validation

B. The rules method is missing required fields

C. The min:0 rule is invalid for numeric fields

D. The class name should be ProductFormRequest

Solution

1. Step 1: Understand the authorize() method role

   The authorize() method controls if the request is allowed. Returning false denies the request before validation.

2. Step 2: Effect of returning false in authorize()

   When authorize() returns false, Laravel automatically denies the request, so validation rules are not applied and the request fails authorization.

3. Final Answer:

   The authorize method returns false, blocking validation -> Option A

4. Quick Check:

   authorize() false blocks request [OK]

Hint: authorize() must return true to run validation [OK]

Common Mistakes:

• Ignoring authorize() method effect
• Thinking min:0 is invalid for numeric
• Believing class name affects validation

5. You want to create a Form Request that validates an optional email field but only if it is present, and it must be a valid email format. Which rule should you use in the rules() method?

hard

A. 'email' => 'nullable|email'

B. 'email' => 'sometimes|email'

C. 'email' => 'required|email'

D. 'email' => 'present|email'

Solution

1. Step 1: Understand optional validation rules

   To validate a field only if it is present in the input, Laravel uses the sometimes rule.

2. Step 2: Compare rules for optional email

   nullable allows null values and skips subsequent rules if null; present requires the field to exist even if empty; sometimes applies validation only if the field is sent.

3. Final Answer:

   'email' => 'sometimes|email' -> Option B

4. Quick Check:

   Use sometimes for optional fields [OK]

Hint: Use sometimes to validate only if field exists [OK]

Common Mistakes:

• Using required which forces presence
• Using nullable which requires field present but can be null
• Using present which requires field always present