Data Next

data-next.cs

public class Person 
{
    public string FirstName { get; }

    public string LastName { get; }
}

[ExtendObjectType(typeof(Person))]
public class PersonExtension 
{
    public Expression DisplayName = (Person p ) => $"{p.FirstName} {p.LastName}";

    public string DisplayName(
        [Field("firstName")]string firstName, 
        [Field("lastName")]string lastName])
        => $"{p.FirstName} {p.LastName}";

    public string DisplayName(
        [Member(nameof(Person.FirstName))]string firstName, 
        [Member(nameof(Person.LastName))]string lastName])
        => $"{p.FirstName} {p.LastName}";
}

public interface IFilterinContext{}


// customer land 🪄
public static class FooBarDatabaseMapper 
{
    public static FooBarQuery Map(this IFilteringContext context) { /* */}
}

/*
.Select(x => new Person { FirstName = x.FirstName,  LastName = x.LastName, Displ})

  1. Map the output type to filtering
  2. FilteringContext , ProjectionContext et al
  3.  lift expression from output type to filtering projection and sorting
  3.1 Projection  Engine

.Select(x => new object[] { x.FirstName,  x.LastName, $"{x.FirstName} {x.LastName}"})

firstName x => x.GetParent<object[]>()[0];
lastName x => x.GetParent<object[]>()[1];
displayName x => x.GetParent<object[]>()[1];

*/