Is there a clean way to to map two fields to one

[jacokok]

I am looking for a clean way to map Create and LastModified to a Modified field when lastModified is null.

public class Entity {
    public DateTime Created { get; set; }
    public DateTime? LastModified { get; set; }
}

public class EntityDTO {
    public DateTime Created { get; set; }
    public DateTime? LastModified { get; set; }
    public DateTime Modified { get; set; }
}

// Want to map fields to something like this.
Modified = p.LastModified ?? p.Created;

I was able to match it using before / after map

[Mapper]
public partial class EntityMapper
{
    private partial EntityDto _ToDto(Entity e);

    [UserMapping(Default = true)]
    public EntityDto ToDTO(Entity e)
    {
        var dto = _ToDto(e);
        dto.Modified = e.LastModified ?? e.Created;
        return dto;
    }
}

public static partial IQueryable<EntityDto> ProjectToDTO(this IQueryable<Entity> q);

Unfortunately with this way it does not work when calling it from IQueryable, any tips will be appreciated.

[latonz]

Have you tried using MapProperyFromSource.Use, see docs?

[jacokok]

That worked thank you so much! Don't know how I missed it.
Appreciate the work and response!