Laravel 5.5 validation ruleception (rule inside rule)

Laravel’s 5.5 Validation Rules are awesome. They let you add custom validations into your code in an organized way.
I think they were made as a simple atomic validation rule, that only deals with one validation at a time. That’s why they only take one attribute — value; they are supposed to replace the string validations.
For more complicated and heavy attribute linked validations, they recommend creating a custom Request and add validation there…

But I still needed to make a simple validation: validate the user’s phone if it had changed.
I could fetch the user and append to the validation string: 'unique:users' to the ‘phone’ attribute only if the request()->input('phone’) is defined and not equal to auth()->user()->phonedefined, but it’d get messy really soon.

Laravel’s validation Rule

With php artisan make:rule PhoneUniquewe can now start to build this rule. We’ll have to take the user in the constructor, and then, on passes(), call the ‘unique:users’ rule only if the user’s phone changed.

use Illuminate\Support\Facades\Validator;
use Illuminate\Contracts\Validation\Rule;

class PhoneUnique implements Rule
{
    protected $user;

    public function __construct(User $user)
    {
        $this->user = $user;
    }

    public function passes($attribute, $value)
    {
        // If it hasn't changed, then it passes
        if (!$value || $this->player->phone === $value) {
            return true;
        }
        $validator = Validator::make([
              'phone' => $value
           ], [
              'phone' => 'unique:users'
           ]);

        return $validator->passes();

    }

    public function message()
    {
        return 'Player\'s phone must be unique.';
    }
}

So now it’s simpler. 🙂

$user = auth()->user();
request()->validate([
      'phone' => ['required', new PhoneUnique($user)]
]);

Make it prettier

As I know that I’ll be using a lot of this in my project (the ValidPhone rule can be digits + check for country code + check for length + not duplicated), I figured it’d be nice to have it reusable. That’s why I made BaseRule that has that functionality:

Now extending this base class on your rules, you’ll be able to nest validations with other rules.

Example:

use Illuminate\Contracts\Validation\Rule;

class PlayerPhoneUnique extends BaseRule implements Rule
{
    protected $user;

    public function __construct(User $user)
    {
        $this->user = $user;
    }

    public function passes($attribute, $value)
    {
        if (!$value || $this->player->phone === $value) {
            return true;
        }

        // Needs the attribute parameter cause that's the field used by unique
        return $this->validate($value, 'unique:players', $attribute);
    }

    public function message()
    {
        return 'Player\'s phone must be unique.';
    }
}

Now, as validate stores the validator, you can add multiple rules, and then on message() you can access it and check for it’s errors.

More examples

• Multiple rules on same validator

public function passes($attribute, $value)
{
    return $this->validate($value, [
        'required', 'digits:10', new PhoneUnique($this->user)
    ], $attribute);
}

• Multiple validators

public function passes($attr, $value)
{
    if (! $this->validate($value, ['required', 'digits:10'], $attr)
    ) {
        return false;
    }
    return $this->validate($value,
             new PhoneUnique($this->user), $attr);
}

Custom message using validation errors
The last invalid should be the one returned on getValidator()

public function message()
{
    $errors = $this->getValidator()->errors();

    if ($errors->any()) {
        return $errors->all();
    }
    
    return 'Some other error';
}

Hope it was useful.