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.