Have you thought about adding support for boolean operators in the rule declarations? For example, "empty||valid_email" => "empty or a valid email", or "valid_email&&matches[email]" => "valid email and matches the 'email' field"? Basically, support for !, && (easy since this is the default behavior), and ||. To be honest, the use cases for this functionality is pretty limited but I think it'd be a nice feature to add just for the sake of practice. It would make handling error messages a little more complex though.
I tried to add something like this to a small validation library I wrote about a year ago. I think that part worked pretty well but otherwise it wasn't very well designed. Another problem I ran into was the lack of support for rules that depended on asynchronous operations.
I tried to add something like this to a small validation library I wrote about a year ago. I think that part worked pretty well but otherwise it wasn't very well designed. Another problem I ran into was the lack of support for rules that depended on asynchronous operations.