> ## Documentation Index
> Fetch the complete documentation index at: https://nova.laravel.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Validation

> Nova provides a variety of ways to validate your resource fields.

Unless you like to live dangerously, any Nova fields that are displayed on the Nova creation / update pages will need some validation. Thankfully, it's a cinch to attach all of the Laravel validation rules you're familiar with to your Nova resource fields. Let's get started.

## Rules

### Attaching Rules

When defining a field on a resource, you may use the `rules` method to attach [validation rules](https://laravel.com/docs/validation#available-validation-rules) to the field:

```php app/Nova/~Resource.php {16} theme={null}
use Laravel\Nova\Fields\Text;
use Laravel\Nova\Http\Requests\NovaRequest;

// ...

/**
 * Get the fields displayed by the resource.
 *
 * @return array<int, \Laravel\Nova\Fields\Field>
 */
public function fields(NovaRequest $request): array
{
    return [
        Text::make('Name')
            ->sortable()
            ->rules('required', 'max:255'),
    ];
}
```

Of course, if you are leveraging Laravel's support for [validation rule objects](https://laravel.com/docs/validation#using-rule-objects), you may attach those to resources as well:

```php theme={null}
use App\Rules\ValidState;
use Laravel\Nova\Fields\Text;

// ...

Text::make('State')
    ->sortable()
    ->rules('required', new ValidState),
```

You may also provide rules to the `rules` method via an array or Closure:

```php theme={null}
use App\Rules\ValidState;
use Laravel\Nova\Fields\Text;

// ...

// Using an array...
Text::make('State')->rules(['required', new ValidState]),

// Using a Closure...
Text::make('State')->rules(fn ($request) => [
    'required', 
    new ValidState(),
]);
```

Additionally, you may use [custom closure rules](https://laravel.com/docs/validation#using-closures) to validate your resource fields:

```php {7-12} theme={null}
use Laravel\Nova\Fields\Text;

// ...

Text::make('State')
    ->sortable()
    ->rules('required', function($attribute, $value, $fail) {
        if (strtoupper($value) !== $value) {
            return $fail('The '.$attribute.' field must be uppercase.');
        }
    }),
```

### Creation Rules

If you would like to define rules that only apply when a resource is being created, you may use the `creationRules` method:

```php {8} theme={null}
use Laravel\Nova\Fields\Text;

// ...

Text::make('Email')
    ->sortable()
    ->rules('required', 'email', 'max:255')
    ->creationRules('unique:users,email'),
```

### Update Rules

Likewise, if you would like to define rules that only apply when a resource is being updated, you may use the `updateRules` method. If necessary, you may use `resourceId` place-holder within your rule definition. This place-holder will automatically be replaced with the primary key of the resource being updated:

```php {9} theme={null}
use Laravel\Nova\Fields\Text;

// ...

Text::make('Email')
    ->sortable()
    ->rules('required', 'email', 'max:255')
    ->creationRules('unique:users,email')
    ->updateRules('unique:users,email,{{resourceId}}'),
```

## After Validation Hooks

Nova also provides several methods that allow you to perform tasks after a resource has been validated, providing the opportunity to perform more custom validation before the resource is persisted to the database:

* [`afterValidation`](#after-validation-method)
* [`afterCreationValidation`](#after-creation-validation-method)
* [`afterUpdateValidation`](#after-update-validation-method)

#### The `afterValidation` Method

The `afterValidation` method will always be called after a resource has been validated during its creation or during an update. This method will be called before calling `afterCreationValidation` or `afterUpdateValidation`:

```php app/Nova/~Resource.php theme={null}
use Illuminate\Contracts\Validation\Validator as ValidatorContract;
use Laravel\Nova\Http\Requests\NovaRequest;

// ... 

/**
 * Handle any post-validation processing.
 *
 * @return void
 */
protected static function afterValidation( 
    NovaRequest $request, 
    ValidatorContract $validator
) {
    if (self::somethingElseIsInvalid()) {
        $validator->errors()->add('field', 'Something is wrong with this field!');
    }
}
```

#### The `afterCreationValidation` Method

The `afterCreationValidation` method will be called after a resource that is being created has been validated:

```php app/Nova/~Resource.php theme={null}
use Illuminate\Contracts\Validation\Validator as ValidatorContract;
use Laravel\Nova\Http\Requests\NovaRequest;

// ... 

/**
 * Handle any post-creation validation processing.
 * 
 * @return void
 */
protected static function afterCreationValidation(
    NovaRequest $request, 
    ValidatorContract $validator
) {
    if (self::somethingElseIsInvalid()) {
        $validator->errors()->add('field', 'Something is wrong with this field!');
    }
}
```

#### The `afterUpdateValidation` Method

The `afterUpdateValidation` method will be called after a resource that is being updated has been validated:

```php app/Nova/~Resource.php theme={null}
use Illuminate\Contracts\Validation\Validator as ValidatorContract;
use Laravel\Nova\Http\Requests\NovaRequest;

// ... 

/**
 * Handle any post-update validation processing.
 *
 * @return void
 */
protected static function afterUpdateValidation(
    NovaRequest $request, 
    ValidatorContract $validator
) {
    if (self::somethingElseIsInvalid()) {
        $validator->errors()->add('field', 'Something is wrong with this field!');
    }
}
```