Question

I’m using the new EntityFramework 4.1 with POCO objects, in conjunction with the DataAnnotation framework.

When EntityFramework needs to create a proxy class (for example, lazy loading virtual properties), all of my data annotations are lost. Is there some way that my ModelMetaData can come from the class that was proxied, instead of the proxy class?

I know that I have the choice to disable proxy creating (context.Configuration.ProxyCreationEnabled) but this seems like a poor answer. This should be something that’s been solved, I would think.

Here’s some example code:

public class Person
{
    [Required, Display(Name = "Display That Name")]
    public string DisplayName { get; set; }
}

And then in my model metadata in the view, the type is: Person_9C92B92D56F6F4F0FB1686526D585438A05323CC72E457C2152796E8866297E1 (FullName = "System.Data.Entity.DynamicProxies.Person_9C92B92D56F6F4F0FB1686526D585438A05323CC72E457C2152796E8866297E1"}), my metadata is gone, and the displayname renders out at “DisplayName” not “Display That Name”.

Any suggestions?

Answer 1

I figured out one possible solution. Not sure if there are better ones. First I wrote a new ModelMetadataProvider:

public class IgnoreProxiesDataAnnotationsModelMetadataProvider : System.Web.Mvc.DataAnnotationsModelMetadataProvider
{
    protected override ModelMetadata CreateMetadata(IEnumerable<Attribute> attributes, Type containerType, Func<object> modelAccessor, Type modelType, string propertyName)
    {
        modelType = ObjectContext.GetObjectType(modelType);
        containerType = ObjectContext.GetObjectType(containerType);

        return base.CreateMetadata(attributes, containerType, modelAccessor, modelType, propertyName);
    }
}

And then registered it in Global.asax application start:

ModelMetadataProviders.Current = new IgnoreProxiesDataAnnotationsModelMetadataProvider();

If there’s a better solution, please let me know!