Question

I am using Domain-Driven-Design have an entity called Menu, need to check if the item has up to three levels, the class is now as shown below:

 public class Menu : Entity
    {

        public virtual AreaMenu AreaMenu { get; set; }

        public virtual Menu MenuPai { get; set; }

        public string Title{ get; set; }

        public virtual Site Site { get; set; }

        public Status Status { get; set; }

        public byte StatusId
        {
            get { return (byte)Status; }
            set { Status = (Status)value; }
        }

        public bool VerifyLevels()
        {
            if (this.MenuPai == null || this.MenuPai.MenuPai == null || this.MenuPai.MenuPai.MenuPai == null || this.MenuPai.MenuPai.MenuPai.MenuPai == null)
                return true;

            return false;
        }
    }

This check levels (public bool VerifyLevels()) , it is right to be here in the entity or is correct that it is in the repository?

Answer 1

Yes, it is right to put validations in your entity. On the other hand, you could call this validation from your repository Save method to validate before saving

E.g.

public class MenuRepository : IMenuRepository
{
    public bool Save(Menu menu)
    {
        if (!menu.VerifyLevels())
            return false;

        if (menu.ID == 0)
            context.Menus.AddObject(menu);
        else
            context.ObjectStateManager.ChangeObjectState(menu, EntityState.Modified);
        context.SaveChanges();

        returns true;
    }
}