Flatten child properties

[iFooledMe]

I am trying to figure out how to handle the need of flattening the id properties in child objects.

Now my response look like this:

{
  "id": "1cec7335-437d-4254-aa6e-4feaa2513f72",
  "createdDate": "2024-05-13T07:04:04.1633826",
  "valueObjectOne": "Test One",
  "valueObjectTwo": "Test One",
  "childEntityOne": {
    "id": "ChildEntityOneId { Value = f7a4f8cc-5ede-4066-8bc3-24669d803223 }",
    "createdDate": "2024-05-13T07:04:04.1626767",
    "valueObjectTwo": "Test One",
    "childEntityTwos": [
      {
        "id": "ChildEntityTwoId { Value = f803f7b7-57d8-4f89-9912-a392a4f1a46e }",
        "createdDate": "2024-05-13T07:04:04.1625806",
        "valueObjectTwo": "Test One"
      },
      {
        "id": "ChildEntityTwoId { Value = ac7e77eb-e1b6-42d5-80a0-f97248fa5e87 }",
        "createdDate": "2024-05-13T07:04:04.1621517",
        "valueObjectTwo": "Test One"
      }
    ]
  }
}

Flattening the id for the top level parrent works just fine like this:
[MapProperty(
nameof(@AggregateOne.Id.Value),
nameof(AggregateOneResponse.Id))]
public partial AggregateOneResponse DomainToResponse(AggregateOne aggregateOne);

But how do I get to the id of the nested ChildEntityOne and to each ChildEntityTwo's? Can't seem to find anything about that in the documentation.

[iFooledMe]

No one?

[iFooledMe]

Can at least someone confirm that I am alive and exist? :-)

[latonz]

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I have fixed the formatting of your post (you can use markdown and thus triple backticks to format blocks of code, see GH markdown). It appears to be a JSON representation of an actual C# object tree, is it? Some values appear to be string serialised and not structured as JSON, for example childEntityOne.id. Is this correct? How does your C# class structure look like?

[iFooledMe]

Hi, sorry if I was a bit impatient. Thanks for looking in to this and a great mapper.

ChildEntityOne have it's own strongly typed ChildEntityOneId type in this case just wrapping a Guid

public readonly record struct ChildEntityOneId(Guid Value)
{
    public static ChildEntityOneId Empty { get; } = default;
    public static ChildEntityOneId CreateNew() => new(Guid.NewGuid());
}

public class ChildEntityOne
{
    public ChildEntityOneId Id { get; set; } = ChildEntityOneId.Empty;
    public DateTime CreatedDate { get; private set; }
    public DateTime UpdatedDate { get; private set; }


    public string ValueObjectOne { get; set; } = string.Empty;
    public string ValueObjectTwo { get; private set; } = string.Empty;


    public AggregateOneId AggregateOneId { get; set; }
    public AggregateOne AggregateOne { get; set; } = null!;

    public ICollection<ChildEntityTwo> ChildEntityTwos { get; set; } = new List<ChildEntityTwo>();


    private ChildEntityOne() { } // Needed for EF core

    public static ChildEntityOne Create(
        string valueObjectOne, 
        string valueObjectTwo, 
        List<ChildEntityTwo> childEntityTwos)
    {
        var createdDate = DateTime.UtcNow;

        return new ChildEntityOne
        {
            Id = ChildEntityOneId.CreateNew(),
            CreatedDate = createdDate,
            UpdatedDate = createdDate,
            ValueObjectOne = valueObjectOne,
            ValueObjectTwo = valueObjectTwo,
            ChildEntityTwos = childEntityTwos
        };
    }
}

Same structure with unique id types goes for The parrent AggregateOne and ChildEntityTwo. As you also can see above ChildEntityOne contains a collection of ChildEntityTwo's (this is of course purely conceptual where I am testing how mapperly can work with a deeply nested complicated situation)

So what I am trying to do is to map a AggregateOne

public readonly record struct ChildEntityOneId(Guid Value)
{
    public static ChildEntityOneId Empty { get; } = default;
    public static ChildEntityOneId CreateNew() => new(Guid.NewGuid());
}

public class ChildEntityOne
{
    public ChildEntityOneId Id { get; set; } = ChildEntityOneId.Empty;
    public DateTime CreatedDate { get; private set; }
    public DateTime UpdatedDate { get; private set; }


    public string ValueObjectOne { get; set; } = string.Empty;
    public string ValueObjectTwo { get; private set; } = string.Empty;


    public AggregateOneId AggregateOneId { get; set; }
    public AggregateOne AggregateOne { get; set; } = null!;

    public ICollection<ChildEntityTwo> ChildEntityTwos { get; set; } = new List<ChildEntityTwo>();


    private ChildEntityOne() { } // Needed for EF core

    public static ChildEntityOne Create(
        string valueObjectOne, 
        string valueObjectTwo, 
        List<ChildEntityTwo> childEntityTwos)
    {
        var createdDate = DateTime.UtcNow;

        return new ChildEntityOne
        {
            Id = ChildEntityOneId.CreateNew(),
            CreatedDate = createdDate,
            UpdatedDate = createdDate,
            ValueObjectOne = valueObjectOne,
            ValueObjectTwo = valueObjectTwo,
            ChildEntityTwos = childEntityTwos
        };
    }
}

Into a response object

public record struct AggregateOneResponse(
    string Id,
    DateTime CreatedDate,
    string ValueObjectOne,
    string ValueObjectTwo,
    ChildEntityOneResponse ChildEntityOne);

public record struct ChildEntityOneResponse(
    string Id,
    DateTime CreatedDate,
    string ValueObjectTwo,
    List<ChildEntityTwoResponse> ChildEntityTwos);

public record struct ChildEntityTwoResponse(
    string Id,
    DateTime CreatedDate,
    string ValueObjectTwo);

As of now it just works out of the box, flattening the AggregateOneId using:

    [MapProperty(
        nameof(@AggregateOne.Id.Value), 
        nameof(AggregateOneResponse.Id))]
    public partial AggregateOneResponse DomainToResponse(AggregateOne aggregateOne);

Resulting in this response:

{
  "id": "119a5f42-586a-4cfa-bc64-cd884c5595a9",
  "createdDate": "2024-05-15T14:05:55.9894546",
  "valueObjectOne": "1",
  "valueObjectTwo": "1",
  "childEntityOne": {
    "id": "ChildEntityOneId { Value = ce17baee-1d1e-478a-a9eb-c3f6878dce1b }",
    "createdDate": "2024-05-15T14:05:55.9888381",
    "valueObjectTwo": "1",
    "childEntityTwos": [
      {
        "id": "ChildEntityTwoId { Value = efc790f1-7178-49d2-929f-ad476b836fc7 }",
        "createdDate": "2024-05-15T14:05:55.9887214",
        "valueObjectTwo": "1"
      },
      {
        "id": "ChildEntityTwoId { Value = c72c853b-ccf9-4ac4-949a-e46f7ae6ba40 }",
        "createdDate": "2024-05-15T14:05:55.987897",
        "valueObjectTwo": "1"
      }
    ]
  }
}

...which is fantastic!!!

It is just the nested unique Id types of the nested child objects that need to be flattened in the rsponse.
As of now I have not used any custom JSON serailization convertion. But that is of course also an option to handle this.
I am just curious too see if this is possible to achieve with mapperly withouth it?

[iFooledMe]

Sorry here is the AggregateOne I am trying to map to the response:

[ModelBinder(BinderType = typeof(StrongIdBinder))]
public readonly record struct AggregateOneId(Guid Value)
{
    public static AggregateOneId Empty { get; } = default;
    public static AggregateOneId CreateNew() => new(Guid.NewGuid());
}

public class AggregateOne
{
    public AggregateOneId Id { get; private set; } = AggregateOneId.Empty;
    public DateTime CreatedDate { get; private set; }
    public DateTime UpdatedDate { get; private set; }


    public string ValueObjectOne { get; private set; } = string.Empty;
    public string ValueObjectTwo { get; private set; } = string.Empty;


    public ChildEntityOne ChildEntityOne { get; private set; } = null!;


    private AggregateOne() { } // Needed for EF core

    public static AggregateOne Create(
        string valueObjectOne, 
        string valueObjectTwo,
        ChildEntityOne childEntityOne)
    {
        var createdDate = DateTime.UtcNow;

        return new AggregateOne
        {
            Id = AggregateOneId.CreateNew(), 
            CreatedDate = createdDate,
            UpdatedDate = createdDate,
            ValueObjectOne = valueObjectOne,
            ValueObjectTwo = valueObjectTwo,
            ChildEntityOne = childEntityOne
        };
    }
}

[iFooledMe]

Actually, I just figured out that I can use custom mapping like this:
// Custom mapping
private AggregateOneId MapToAggregateOneId(string id) => new AggregateOneId(Guid.Parse(id));
private string MapToAggregateOneIdString(AggregateOneId id) => id.Value.ToString();
private string MapToChildEntityOneIdString(ChildEntityOneId id) => id.Value.ToString();
private string MapToChildEntityTwoIdString(ChildEntityTwoId id) => id.Value.ToString();

Very clean! 

Sorry for being a bit slow here :-) Thanks for taking your time and again for a excelent mapper.