Form request classes in Laravel - Step-by-Step Execution

Concept Flow - Form request classes

User submits form

↓

FormRequest class intercepts

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Validate input rules

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Controller

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Show errors

When a user submits a form, the FormRequest class checks input against rules. If valid, data goes to the controller. If invalid, user sees errors.

Execution Sample

Laravel

public function rules()
{
    return [
        'email' => 'required|email',
        'password' => 'required|min:8'
    ];
}

Defines validation rules for email and password fields in a FormRequest class.

Execution Table

Step	Action	Input Data	Validation Result	Next Step
1	Receive form data	{email: '[e-mail]', password: 'secret123'}	Not checked yet	Validate input
2	Check 'email' field	'[e-mail]'	Passes 'required' and 'email' rules	Check next field
3	Check 'password' field	'secret123'	Passes 'required' and 'min:8' rules	All fields valid
4	All validations passed	N/A	Valid	Send data to controller
5	Controller processes data	Valid data	N/A	Complete request
6	If invalid input example	{email: '', password: '123'}	Fails 'email' required and 'password' min:8	Redirect back with errors

💡 Validation stops when all rules pass or any rule fails, then proceeds accordingly.

Variable Tracker

Variable	Start	After Step 2	After Step 3	Final
email	[e-mail]	[e-mail]	[e-mail]	Valid
password	secret123	secret123	secret123	Valid
validation_status	Not checked	Partial pass	All pass	Valid

Key Moments - 2 Insights

Why does the form redirect back instead of calling the controller?

If any validation rule fails (see step 6 in execution_table), Laravel automatically redirects back with error messages instead of running controller code.

How does Laravel know which rules to apply?

The rules() method in the FormRequest class returns the validation rules array (shown in execution_sample), which Laravel uses to check each input field.

Visual Quiz - 3 Questions

Look at the execution_table at step 3, what is the validation result for the password field?

A Fails 'required' rule

B Passes 'required' and 'min:8' rules

C Fails 'min:8' rule

D Not checked yet

💡 Hint

Check the 'Validation Result' column at step 3 in the execution_table.

At which step does Laravel decide to send data to the controller?

A Step 2

B Step 6

C Step 4

D Step 1

💡 Hint

Look for the step where 'All validations passed' and 'Send data to controller' appear in the execution_table.

If the email field is empty, how does the execution_table change?

A Step 2 shows failure on 'email' required rule

B Step 3 shows failure on 'password' rule

C Step 4 sends data to controller anyway

D No change, validation passes

💡 Hint

Refer to step 6 in execution_table where invalid input causes failure on 'email' required rule.

Concept Snapshot

Form Request Classes in Laravel:
- Create a FormRequest class to handle validation.
- Define rules() method returning validation rules.
- Laravel auto-validates input before controller runs.
- On failure, redirects back with errors.
- On success, controller receives validated data.

Full Transcript

When a user submits a form in Laravel, the FormRequest class intercepts the data. It runs the rules defined in the rules() method to check each input field. If all fields pass validation, the data is sent to the controller for processing. If any field fails, Laravel automatically redirects the user back to the form with error messages. This process helps keep controller code clean and validation centralized. The execution table shows each step: receiving data, checking each field, deciding if data is valid, and either continuing or redirecting. Variables like email and password hold input values and their validation status updates as checks run. Understanding this flow helps beginners see how Laravel manages form validation smoothly.