Question

I have a couple model classes like so:

public class MyModelBase
{
    public string Name { get; set; }
}

public class MyModel : MyModelBase
{
    public string SomeOtherProperty { get; set; }
}

How can MyModel add a [Required] attribute to the Name property?

Answer 1

Try using a metadata class. It’s a separate class that is referenced using attributes that lets you add data annotations to model classes indirectly.

e.g.

[MetadataType(typeof(MyModelMetadata))]
public class MyModel : MyModelBase {
  ... /* the current model code */
}


internal class MyModelMetadata {
    [Required]
    public string Name { get; set; }
}

ASP.NET MVC (including Core) offers similar support for its attributes like FromQuery, via the ModelMetadataTypeAttribute.