public virtual void RegisterTo(Class @class)
{
// Business rules
@class.Validation().NotNull("class");
if (registrations.Where(x => x.Class.Id == @class.Id).Count() > 0)
{
throw new InvalidOperationException("You can not register a student to a class he already registered");
}
if (passedClasses.Where(x => x == @class.Id).Count() > 0)
{
throw new InvalidOperationException("You can not register a student to a class he already passed");
}
// State changes
registrationSequence = registrationSequence.Next();
registrations.Add(new Registration(this, registrationSequence.ToId(), @class));
}
private void Apply(StudentRegisteredToClassEvent evt)
{
registrationSequence = registrationSequence.Next();
registrations.Add(new Registration(this, registrationSequence.ToId(), evt.ClassId, evt.Credits));
}