Serialize NodaTime JSON

Question

I am making a prototype project of NodaTime compared to BCL's DateTime, but executing this result gives me recursionLimit exceeded error.

This is the function I am using to JSONify my viewmodel. The error happens after this function returns.

    [HttpPost]
    public JsonResult GetDates(int numOfDatesToRetrieve)
    {
        List<DateTimeModel> dateTimeModelList = BuildDateTimeModelList(numOfDatesToRetrieve);

        JsonResult result = Json(dateTimeModelList, JsonRequestBehavior.AllowGet);
        return result;
    }

My view model is built properly when I inspected it. Here is the code for my view model.

public class DateTimeModel
{
    public int ID;

    public LocalDateTime NodaLocalDateTimeUTC;
    public LocalDateTime NodaLocalDateTime
    {
        get
        {
            DateTimeZone dateTimeZone = DateTimeZoneProviders.Bcl.GetZoneOrNull(BCLTimezoneID);

            //ZonedDateTime zonedDateTime = NodaLocalDateTimeUTC.InUtc().WithZone(dateTimeZone);

            OffsetDateTime offsetDateTime = new OffsetDateTime(NodaLocalDateTimeUTC, Offset.Zero);
            ZonedDateTime zonedDateTime = new ZonedDateTime(offsetDateTime.ToInstant(), dateTimeZone);
            return zonedDateTime.LocalDateTime;
        }
    }

    public OffsetDateTime NodaOffsetDateTime;

    public DateTime BclDateTimeUTC;
    public DateTime BclLocalDateTime
    {
        get
        {
            DateTime utcDateTime = DateTime.SpecifyKind(BclDateTimeUTC, DateTimeKind.Utc);
            TimeZoneInfo nzTimeZone = TimeZoneInfo.FindSystemTimeZoneById(BCLTimezoneID);
            DateTime result = TimeZoneInfo.ConvertTimeFromUtc(utcDateTime, nzTimeZone);
            return result;
        }
    }

    public DateTimeOffset BclDateTimeOffset;
    //public int Offset;
    public string OriginalDateString;
    public string BCLTimezoneID;
}

I am sure that the NodaTime objects are not serializing correctly because when I comment the code from the viewModel the JsonResult is able to execute.

I read this off this page NodaTime API Reference

Code in this namespace is not currently included in Noda Time NuGet packages; it is still deemed "experimental". To use these serializers, please download and build the Noda Time source code from the project home page.

So I downloaded and built the source code and replaced the dll's my project references but I don't know how to implement the JsonSerialization classes.

Can someone explain to me how to use NodaTime.Serialization.JsonNet classes to make my NodaTime objects serializable?

Answer 1

We don't currently have any support for JavaScriptSerializer: I suspect you'll have to use Json.NET for all your JSON serialization. The user guide page on serialization gives a little bit more information, but it does mostly assume you already know about Json.NET.

The good news is that Json.NET is pretty easy to use - you may well find it's as simple as:

var settings = new JsonSerializerSettings();
settings.ConfigureForNodaTime();
string json = JsonConvert.SerializeObject(model, settings);

(Or use JsonSerializer.)

As an aside, the way you're using the Noda Time types is a little odd to say the least - it may well be worth asking another question with details of what you're trying to achieve, and we can work out a more idiomatic way of doing it :)

Answer 2

Serialization is supported for JSON.NET in Noda Time 2.0+.

You'll need to install the package with NuGet:

> Install-Package NodaTime.Serialization.JsonNet

And then configure your serializer settings to use it. This won't work with the default serializer/deserializer - you need to configure one explicitly.

We chose to use one statically. Your usage may be different. Here is an example:

using Newtonsoft.Json;
using NodaTime;
using NodaTime.Serialization.JsonNet; // << Needed for the extension method to appear!
using System;

namespace MyProject
{
    public class MyClass
    {
        private static readonly JsonSerializerSettings _JsonSettings;

        static MyClass()
        {
            _JsonSettings = new JsonSerializerSettings
            {
                // To be honest, I am not sure these are needed for NodaTime,
                // but they are useful for `DateTime` objects in other cases.
                // Be careful copy/pasting these.
                DateFormatHandling = DateFormatHandling.IsoDateFormat,
                DateTimeZoneHandling = DateTimeZoneHandling.Utc,
            };

            // Enable NodaTime serialization
            // See: https://nodatime.org/2.2.x/userguide/serialization
            _JsonSettings.ConfigureForNodaTime(DateTimeZoneProviders.Tzdb);
        }

        // The rest of your code...
    }
}