Working with the validator

Sometimes a more fine-grained control over the validation is required. In such case you can hook into the validator.

##Overwriting messages

It is possible to overwrite the error messages that will be returned when an error fails:

class SongData extends Data
{
    public function __construct(
        public string $title,
        public string $artist,
    ) {
    }

    public static function messages(): array
    {
        return [
            'title.required' => 'A title is required',
            'artist.required' => 'An artist is required',
        ];
    }
}

##Overwriting attributes

In the default Laravel validation rules, you can overwrite the name of the attribute as such:

class SongData extends Data
{
    public function __construct(
        public string $title,
        public string $artist,
    ) {
    }

    public static function attributes(): array
    {
        return [
            'title' => 'titel',
            'artist' => 'artiest',
        ];
    }
}

##Overwriting other validation functionality

Next to overwriting the validator, attributes and messages it is also possible to overwrite the following functionality.

The redirect when a validation failed:

class SongData extends Data
{
    // ...

    public static function redirect(): string
    {
        return action(HomeController::class);
    }
}

Or the route which will be used to redirect after a validation failed:

class SongData extends Data
{
    // ...

    public static function redirectRoute(): string
    {
        return 'home';
    }
}

Whether to stop validating on the first failure:

class SongData extends Data
{
    // ...

    public static function stopOnFirstFailure(): bool
    {
        return true;
    }
}

The name of the error bag:

class SongData extends Data
{
    // ...

    public static function errorBag(): string
    {
        return 'never_gonna_give_an_error_up';
    }
}

##Using dependencies in overwritten functionality

You can also provide dependencies to be injected in the overwritten validator functionality methods like messages , attributes, redirect, redirectRoute, stopOnFirstFailure, errorBag:

class SongData extends Data
{
    public function __construct(
        public string $title,
        public string $artist,
    ) {
    }

    public static function attributes(
        ValidationAttributesLanguageRepository $validationAttributesLanguageRepository
    ): array
    {
        return [
            'title' => $validationAttributesLanguageRepository->get('title'),
            'artist' => $validationAttributesLanguageRepository->get('artist'),
        ];
    }
}

##Overwriting the validator

Before validating the values, it is possible to plugin into the validator. This can be done as such:

class SongData extends Data
{
    public function __construct(
        public string $title,
        public string $artist,
    ) {
    }
    
    public static function withValidator(Validator $validator): void
    {
        $validator->after(function ($validator) {
            $validator->errors()->add('field', 'Something is wrong with this field!');
        });
    }
}

Please note that this method will only be called on the root data object that is being validated, all the nested data objects and collections withValidator methods will not be called.