ASP.NET MVC Project Layering

Question

This is how I imagine my project's layering:

BLL

Should be independent and contain only pure business logic and properties Sample Domain Model:

public class Role
{
 private UnitOfWork uow { get; set; }
 public Role()
 {
 uow = new UnitOfWork();
 }
 public int RoleId { get; set; }
 public string Name { get; set; }
 public string ID { get; set; }
 public string Description { get; set; }
 public int AddRole()
 {
 //Mapping from Business 'Role' type to Data Model 'Role' type
 AutoMapper.Mapper.CreateMap<SoC.BLL.Role, SoC.DAL.Role>();
 var model = AutoMapper.Mapper.Map<SoC.DAL.Role>(this);
 return uow.Roles.Add(model);
 }
}

DAL

Contain generic repository and Unit of work and data model meaning model that will reflect the database. Sample Data Model:

public class Role
{
 [Key]
 public int RoleId { get; set; }
 [Required]
 [StringLength(50, ErrorMessage = "Name Cannot Be More Than 50 Characters")]
 public string Name { get; set; }
 [Required]
 [StringLength(6, ErrorMessage = "ID Cannot Be More Than 6 Characters")]
 public string ID { get; set; }
 [Required]
 [StringLength(250, ErrorMessage = "Description Cannot Be More Than 250 Characters")]
 public string Description { get; set; }
}

Web

This will be ASP.NET MVC app that will use BLL. (Should or should not be aware of DAL?) Sample Controller Action:

public ActionResult Index()
{
 var role = new Role { RoleId = 1, ID = "ADMIN", Name = "Administrator", Description = "Hello World" };
 int check = role.AddRole();
 return View();
}

So, from app I am communicating with the Domain Model which has a AddRole() method that will first map using automapper to the equivalent Data Model and then call Add() of repo method to persist the record.

This way my BLL is becoming a little dependent on AutoMapper and DAL but my DAL seems independent. I am trying to create just a simple layering for a simple yet well maintained project. Please suggest on its problems and improvements.

Answer 1

To start off, I have no idea what a SoC.DAL.Role is. Your namespaces are short abbreviations. This is quite hard to follow for people not really into your project.

Your role can add itself to a repository. This is not behaviour that I would expect. I would have a simple repository class (RoleManager?) that is capable of adding roles.

Role role = new Role(...);
new RoleManager().AddRole(role);

As such, you have 4 layers. One data access layer, one model layer, one domain layer and one GUI layer.

• lbrahim: Thanks for your reply. SoC.DAL is namespace for Data access layer and Role is the type that totally reflects the DB and I call "Data Model". What is the difference between Model and Domain layer in your suggestion?
• lbrahim: Also would not be violating many principles if I create Manager for each Model?
• user42171: Your object Role is responsible for things related to a role. Persisting something to the database is the responsibility for a database connection class. You should not build a Manager per class, but create them on a higher level. An example is per subject (Role management, like Roles, rights and such)
• lbrahim: You have not mentioned the difference between Model and Domain in your answer and also are there any article or examples you can link me to your approach?