How can I use multiple regex expressions with different validation messages

Question

Requirements

I want to check password policies by using multiple regex expressions. For each policy violation I want to display a specific validation message.

Examples:

• You need to use at least 2 numbers
• You need to use at least one upper and one lower case letter
• You need to use at least 8 letters
• ...

Attempt

I tried to use multiple regex expressions (Fluent Validation Match(string expression)), but ASP.NET MVC does not allow to have multiple regex expressions.

The following validation type was seen more than once: regex

Question

How can I use multiple regex validators in Fluent Validation?

Answer 1

You can use custom method defined in Abstract validator:

public class UserValidator : AbstractValidator<User> {
   public UserValidator () {
       Custom(user => { 
           Regex r1 = define regex that validates that there are at least 2 numbers
           Regex r2 = define regex for upper and lower case letters
           string message = string.Empty;
           if(!r1.IsMatch(user.password))
           {
               message += "You need to use at least 2 numbers.";
           }
           if(!r2.IsMatch(user.password))
           {
               message += "You need to use at least one upper and one lower case letter.";
           }

           return message != string.Empty;
              ? new ValidationFailure("Password", message )
              : null; 
       });
   }
}