DDD Using Specification pattern for Validation

Question

I am thinking of using Specification pattern for validation purposes. The hard thing is how to tell the user why some Specification was not satisfied. What if the Spec

Answer 1

I had the same problem. I create Validation decorator for Specification (code is JAVA).

  interface Validator{
    Respond validate(T t)
  }


  class abstract ValidationSpecificationDecorator implements Validator {
  Specification spec;

  ValidationSpecificationDecorator(Specification spec){
    this.spec =  spec;
  }

  public Respond  validate(T t) {
    Respond respond = new Respond();
    if(!spec.IsSatisfiedBy(t){
       respond.add(error(t));
    }
    return respond;
  )

  public abstract Error error(T t);

  }