asp.net mvc - custom validator MVC + validation client side -

i create custom validateur in mvc 4:

public class firstnamevalidator : validationattribute {     private iregistrationconfiguration _registrationconfiguration;     public string category { get; set; }     public bool islocal { get; set; }     public firstnamevalidator()     {         _registrationconfiguration = dependencyresolver.current.getservice<iregistrationconfiguration>();     }     public firstnamevalidator(iregistrationconfiguration registrationconfiguration)     {         _registrationconfiguration = registrationconfiguration;     }      protected override validationresult isvalid(object value, validationcontext validationcontext)     {          if (value == null)         {               return new validationresult("le prénom ne doit pas être vide");         }          else          {              if(string.isnullorempty(value.tostring()))                  return new validationresult("le prénom ne doit pas être vide");                else if(value.tostring().length<2)                  return new validationresult("le prénom doit avoir + que 2 caractères");              else if (value.tostring().length > 30)                  return new validationresult("le prénom doit avoir - que 30 caractères");           }           return null;      }  } 

i user data annotation in viewmodel:

 public class registrationviewmodel {     public string country { get; set; }     public string civility { get; set; }     [firstnamevalidator(category = "registration", islocal = false)]     public string firstname { get; set; }     public string lastname { get; set; } 

}

how can client-side validation ??

1. implement iclientvalidatable in attribute.

   public class firstnamevalidator : validationattribute, iclientvalidatable

2. write javascript adapter , include in view.

3. write javascript validation rule , include in view.

you can search "asp.net mvc 4 custom client side validation" more details. example, can custom data annotation validator or how support client side custom validation