Own field validation, how?

Question

Laravel

There are fields that you need to quickly check, for the most part they are unique, and that's all for one action. How can I do this quickly in laravel? Only validator extensions via service provider? No other way? Directly in an action for example?
Version 5.1

Answer 1

If you only need the functionality of a custom rule once throughout your application, you may use a Closure instead of a rule object.

https://laravel.com/docs/5.7/validation#using-closures