Adding Validation Attributes With an Entity Framework Data Model

Question

Preface Feb 2015 If you are still using Entity Framework EDMX, please do yourself a favor and checkout using Entity Framework Code First instead. The differ

Answer 1

There is a variation of the suggested answers here that allows you to use classes in different assemblies and namespaces. I haven't actually tested it with EF, but I am using this for Swagger codegen API model classes.

In a nutshell: inherit from the model class and add metadata on the inherited class. An added benefit is that with Swagger codegen you can use the API model directly without mapping and for initial forms you can use the protected default ctor.

[MetadataType(typeof(LocalAssemblyModelMetadata))]
public class LocalAssemblyModel : IO.Swagger.Model.OtherAssemblyModel 
{
    public LocalAssemblyModel() : base ()     { }
}



public sealed class LocalAssemblyModelMetadata
{
    [Required(ErrorMessage = "BaseclassProperty is mandatory.")]
    public string BaseclassProperty { get; set; }
}