Question

我正在尝试将域驱动设计与测试驱动开发的组合用于我在ASP.NET MVC 3中构建的此应用程序。我的架构设置了存储库，域模型，视图模型，控制器和视图。所有验证都将在视图模型中处理。我将我的视图模型设置为继承自“IValidatableObject”，以便我的验证属性和我在“Validate”方法中设置的自定义验证都在我的控制器方法调用“ModelState.IsValid”时执行。我遇到的问题是在我的视图模型的Validate方法中访问我的存储库。我需要访问存储库以检查数据库中的重复记录。似乎最好的想法是创建一个IRepository类型的属性，并通过将我的存储库注入视图模型的构造函数来设置该属性。例如：

public class UserViewModel : IValidatableObject
{
       public UserViewModel(User user, IUserRepository userRepository)
       {
              FirstName = user.FirstName;
              LastName = user.LastName;
              UserRepository = userRepository;
              UserName = user.UserName;
       }
       public string UserName { get; set; }
       public string FirstName { get; set; }
       public string LastName { get; set; }
       public IUserRepository UserRepository { get; set; }
       public IEnumerable<ValidationResult> Validate()
       {
           UserCriteria criteria = new UserCriteria { UserName = this.UserName };
           IList<User> users = UserRepository.SearchUsers(criteria);

           if (users != null && users.count() > 0)
           {
               yield return new ValidationResult("User with username " + this.UserName + " already exists."
           }
       }
}

你们认为这是一个好主意吗？

Answer 1

这很好，但如果我是你，我会用

...
private readonly Func<IUserRepository> userRepositoryFactory;
...
public IEnumerable<ValidationResult> Validate()  
   {  
       UserCriteria criteria = new UserCriteria { UserName = this.UserName };  
       using(var UserRepository = userRepositoryFactory())
       {
           IList<User> users = UserRepository.SearchUsers(criteria);  

           if (users != null && users.count() > 0)  
           {  
               yield return new ValidationResult("User with username " + this.UserName + " already exists."  
           }  
       }
   }

Answer 2

您可以添加域服务类，以使对象与您的条件匹配，并在域服务级别验证

 public class PurchaseOrder
    {
        public string Id { get; private set; }
        public string PONumber { get; private set; }
        public string Description { get; private set; }
        public decimal Total { get; private set; }
        public DateTime SubmissionDate { get; private set; }
        public ICollection<Invoice> Invoices { get; private set; }

        public decimal InvoiceTotal
        {
            get { return this.Invoices.Select(x => x.Amount).Sum(); }
        }

    }

    public class PurchaseOrderService
    {
        public PurchaseOrderService(IPurchaseOrderRepository repository)
        {
            this.repository = repository;
        }

        readonly IPurchaseOrderRepository repository;

        public void CheckPurchasedOrderExsist(string purchaseOrderId)
        {
                var purchaseOrder = this.repository.Get(purchaseOrderId);
                if (purchaseOrder != null)
                    throw new Exception("PO already exist!");
        }
    }

视图模型最佳实践中的ASP.NET MVC自定义验证

2 个答案: