AutoMapper and is*Specified properties

Question

Hi,

I have a bunch of XSD.exe-generated data contract classes which for all optional elements have a pair of C# properties like

int Amount {get; set;}
bool isAmountSpecified {get; set;}

On the other side of mapping arena I have a nullable int like

int? Amount {get; set;}

Ideally I'd like for AutoMapper to be able to recognize such patterns and know how to map things in both directions without me having to specify a mapping for each individual property. Is this possible?

Answer 1

I honestly have no idea whether AutoMapper will do that (since I don't use AutoMapper much), but I know that protobuf-net supports both those patterns, so you could use Serializer.ChangeType<,>(obj) to flip between them.

The current version is, however, pretty dependent on having attributes (such as [XmlElement(Order = n)]) on the members - I don't know if that causes an issue? The in progress version supports vanilla types (without attributes), but that isn't complete yet (but soon).

Example:

[XmlType]
public class Foo
{
    [XmlElement(Order=1)]
    public int? Value { get; set; }
}
[XmlType]
public class Bar
{
    [XmlElement(Order = 1)]
    public int Value { get; set; }
    [XmlIgnore]
    public bool ValueSpecified { get; set; }
}
static class Program
{
    static void Main()
    {
        Foo foo = new Foo { Value = 123 };
        Bar bar = Serializer.ChangeType<Foo, Bar>(foo);
        Console.WriteLine("{0}, {1}", bar.Value, bar.ValueSpecified);

        foo = new Foo { Value = null };
        bar = Serializer.ChangeType<Foo, Bar>(foo);
        Console.WriteLine("{0}, {1}", bar.Value, bar.ValueSpecified);

        bar = new Bar { Value = 123, ValueSpecified = true };
        foo = Serializer.ChangeType<Bar, Foo>(bar);
        Console.WriteLine(foo.Value);

        bar = new Bar { Value = 123, ValueSpecified = false };
        foo = Serializer.ChangeType<Bar, Foo>(bar);
        Console.WriteLine(foo.Value);
    }
}

Answer 2

OK, yesterday I've had a brief discussion with Jimmy Bogard, author of AutoMapper, and basically what I'm looking for is currently not possible. Support for such conventions will be implemented some time in the future (if I understood him correctly :) ).