如何使用EntityFramework建立Rich Domain模型

Question

Im using Entity Framework 4.2 (Code First) to create my database, which works fine so far,but now im facing a problem that is very easy to overcome in Hibernate or JPA but im not able see it here.

I have define a User object which have a property called Password, i want to customize the {get;set;} operations in order to have certain logic when setting the password (i want to stored a hash version of it, but i want that logic inside my domain object ala DDD). But im facing that when materializing an object from the database my setter is being called and is not using directly the private field.

Im trying to build a Rich Domain Object model and avoiding DAO/Repository pattern on this.

Is this possible thru Entity Framework, or will i be force to use DAO/Repository patterns.

Below is an extraction of my User object:

public class User
{
    [Key]
    public string LoginId { get; set; }

    [Required]
    private string password;

    public string Password
    {
        get { return password; }
        set {
            //Random Salt
            byte[] s;
            using (RNGCryptoServiceProvider prov = new RNGCryptoServiceProvider())
            {
                s = new byte[20];
                prov.GetBytes(s);
            }
            this.salt = Convert.ToBase64String(s);
            //Random salt                
            password = ComputeHash(value);
            }
    }

    [Required]
    private string salt;
    public string Salt { 
                         get { return this.salt; }
                         set { throw new InvalidOperationException("Salt is not an assignable property. Assign a password first to your model and a Salt will get created."); }
                       }

    public bool ValidatePassword(string clearTextPassword)
    {
        return this.Password == this.ComputeHash(clearTextPassword);
    }
    public string ComputeHash(string value)
    {
       ...
       return hashVersion of value;

    }

}

Answer 1

Start by adding an encrypted passwordstring value object (immutable)

for instance

public class EncryptedString
{
  public string Value { get;private set; }
  public string Hash { get;private set; }
  bool Validate(string password);

  public Encrypted(string value)
  {
     // Put logic here
  }
}

In EF it is called a complex type