Serialized MS Graph objects fail when received by Graph

[thoffmann-fms]

My existing code uses either Newtonsoft or System.Text.Json to serialize various MS Graph objects and then Post/Patch the result to the Graph endpoint as needed. This worked fine until I upgraded the Graph library to current.

Now, this code:

           ItemBody ib = new ItemBody();
           ib.Content = "<b>Hypertext body</b>";

           Event ev = new Event();
           ev.Body = ib;
           ev.Subject = "New Subject";
           string request = JsonSerializer.Serialize(ev, GraphData.JsonSerializeOptionGraph);

        public static readonly JsonSerializerOptions JsonSerializeOptionGraph = new JsonSerializerOptions
        {
            PropertyNameCaseInsensitive = false,
            DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
            IgnoreReadOnlyProperties = true,
            PropertyNamingPolicy = JsonNamingPolicy.CamelCase
        };

produces this string:
"body":{"additionalData":{},"content":"\u003Cb\u003EHypertext body\u003C/b\u003E"},"subject":"New Subject","additionalData":{},"odataType":"#microsoft.graph.event"}

Here's a snippet of the ItemBody object:

[GeneratedCode("Kiota", "1.19.0")]
public class ItemBody : IAdditionalDataHolder, IBackedModel, IParsable
{
    //
    // Summary:
    //     Stores additional data not described in the OpenAPI description found when deserializing.
    //     Can be used for serialization as well.
    public IDictionary<string, object> AdditionalData
    {
        get
        {
            return BackingStore.Get<IDictionary<string, object>>("AdditionalData") ?? new Dictionary<string, object>();
        }
        set
        {
            BackingStore.Set("AdditionalData", value);
        }
    }

    //
    // Summary:
    //     Stores model information.
    public IBackingStore BackingStore { get; private set; }

    //
    // Summary:
    //     The content of the item.
    public string? Content
    {
        get
        {
            return BackingStore?.Get<string>("content");
        }
        set
        {
            BackingStore?.Set("content", value);
        }
    }

When that is Patch-ed to Graph it tells me "additionaData" is not valid:
{"error":{"code":"RequestBodyRead","message":"The property 'additionalData' does not exist on type 'microsoft.graph.itemBody'. Make sure to only use property names that are defined by the type or mark the type as open type."}}

I'm not able to re-write my whole application to use the Graph SDK, so is there a way to get the Graph objects serialized properly?

[andrueastman]

Thanks for raising this @thoffmann-fms

Any chance you can try using the serialization helpers as outlined in the documentation below?

https://learn.microsoft.com/en-us/openapi/kiota/serialization?tabs=csharp#serialization-helpers

Kiota abstracts away the use of a specific library/serializer and decouples the serialization information and the serialization format which can make some serialization scenarios more complex.

[thoffmann-fms]

That documentation is missing some key information. The method listed aborts.

Exception thrown: 'System.InvalidOperationException' in Microsoft.Kiota.Abstractions.dll
Content type application/json does not have a factory registered to be parsed

        try
        {
            Microsoft.Graph.Models.Event ev = new Microsoft.Graph.Models.Event();
            ev.Subject = "New Subject";
            ev.Body = new ItemBody { Content = "<b>Hypertext body</b>" };
            var result = await KiotaJsonSerializer.SerializeAsStringAsync(ev);
            Debug.WriteLine(result);
        }
        catch (Exception ex)
        {
            Debug.WriteLine(ex.Message);
            Debugger.Break();
        }

[baywet]

Thank you for the additional information.
Here is some more background about this error.
microsoft/kiota-dotnet#397

[thoffmann-fms]

Thanks, that looks like the fix. My sample test worked, we'll get this put into real code on Thursday and see how it goes there.

            ApiClientBuilder.RegisterDefaultSerializer<JsonSerializationWriterFactory>();

            Microsoft.Graph.Models.Event ev = new Microsoft.Graph.Models.Event();
            ev.Subject = "New Subject";
            ev.Body = new ItemBody { Content = "<b>Hypertext body</b>" };
            var result = await KiotaJsonSerializer.SerializeAsStringAsync(ev);
            Debug.WriteLine(result);

produces:

{"@odata.type":"#microsoft.graph.event","body":{"content":"\u003Cb\u003EHypertext body\u003C/b\u003E"},"subject":"New Subject"}

[thoffmann-fms]

Just to add a note, I found out that to deserialize, a call to
ApiClientBuilder.RegisterDefaultDeserializer<JsonParseNodeFactory>();
is required to allow
await KiotaJsonSerializer.DeserializeAsync<Event>(json)
to work.