mapping private property entity framework code first

Question

I am using EF 4.1 and was look for a nice workaround for the lack of enum support. A backing property of int seems logical.

    [Required]
    public VenueType Type
    {
        get { return (VenueType) TypeId; }
        set { TypeId = (int) value; }
    }

    private int TypeId { get; set; }

But how can I make this property private and still map it. In other words:

How can I map a private property using EF 4.1 code first?

Answer 1

Here's a convention you can use in EF 6+ to map selected non-public properties (just add the [Column] attribute to a property).

In your case, you'd change TypeId to:

    [Column]
    private int TypeId { get; set; }

In your DbContext.OnModelCreating, you'll need to register the convention:

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Add(new NonPublicColumnAttributeConvention());
    }

Finally, here's the convention:

/// <summary>
/// Convention to support binding private or protected properties to EF columns.
/// </summary>
public sealed class NonPublicColumnAttributeConvention : Convention
{

    public NonPublicColumnAttributeConvention()
    {
        Types().Having(NonPublicProperties)
               .Configure((config, properties) =>
                          {
                              foreach (PropertyInfo prop in properties)
                              {
                                  config.Property(prop);
                              }
                          });
    }

    private IEnumerable<PropertyInfo> NonPublicProperties(Type type)
    {
        var matchingProperties = type.GetProperties(BindingFlags.SetProperty | BindingFlags.GetProperty | BindingFlags.NonPublic | BindingFlags.Instance)
                                     .Where(propInfo => propInfo.GetCustomAttributes(typeof(ColumnAttribute), true).Length > 0)
                                     .ToArray();
        return matchingProperties.Length == 0 ? null : matchingProperties;
    }
}