Deserializer only links attributes and not included relationships

For a simple model like below

    public class Customer : Identifiable
    {
        [HasMany] public List<Order> Orders { get; set; }
    }

    public class Order : Identifiable
    {
        [HasMany] public List<Invoice> Invoices { get; set; }
    }

    public class Invoice : Identifiable { }

Serializer works fine and get customer with included relationship returns the desired response /api/v1/customers?included=orders.invoices

{
    "data": {
        "attributes": {},
        "relationships": {
            "orders": {
                "links": {
                    "self": "https://localhost:44351/customers/1234/relationships/orders",
                    "related": "https://localhost:44351/customers/1234/orders"
                },
                "data": [
                    {
                        "type": "orders",
                        "id": "4567"
                    }
                ]
            }
        },
        "type": "customers",
        "id": "1234"
    },
    "included": [
        {
            "attributes": {},
            "relationships": {
                "invoices": {
                    "links": {
                        "self": "https://localhost:44351/orders/4567/relationships/invoices",
                        "related": "https://localhost:44351/orders/4567/invoices"
                    },
                    "data": [
                        {
                            "type": "invoices",
                            "id": "7890"
                        }
                    ]
                }
            },
            "type": "orders",
            "id": "4567"
        },
        {
            "attributes": {},
            "type": "invoices",
            "id": "7890"
        }
    ]
}

However on using the same json as input for post/put operation and trying to deserialize into customer instance with all fields/relationships populated, it does not load included relationship. In this instance, customer has orders attributes populated but invoices is appearing blank.

Is it because we are only setting attributes and not relationship. Can we please modify it to add second level or more relationship be included as well. https://github.com/json-api-dotnet/JsonApiDotNetCore/blob/9059560ffdaa9cc263fd352bb7dc1106255d6148/src/JsonApiDotNetCore/Serialization/JsonApiDeSerializer.cs#L323

[maurei]

I think it should be deserializing whatever is available in json input and not create/update nested relationships

I totally agree, I’m in!

Work that will be involved:

1. Serialization layer needs to be decoupled (related to #263, #253): this will affect JsonApiContext , (in particular, I think, the exposure of HttpContextAccessor) so that we can decouple it from query params.
2. Need to prevent nested relationship create/update in default implementation of repository/service layer
3. Need to investigate impact on other components of the framework
4. Lots of rewriting of tests of serializers where mocks of JsonApiContext are used

This will surely involve breaking changes in the API. I hope I can make a proposal where to start on soon. If you feel like getting involved, we would greatly encourage that!

[maurei]

resolved in #558