Deserializing NodaTime Instant from System.Text.Json

Question

I'm using Noda Time in an ASP.NET Core project and a model that contains two Instant properties.

public class Template
{
    //... redacted bits

    public Instant CreateDt { get; set; }
    public Instant LastmodDt { get; set; }
}

The info in the database is as I expect "out of box." However getting back the values via API returns empty object properties like this:

{
    //... redacted bits

    "createDt": {},
    "lastmodDt": {}
}

How do I get back the same date I put in, or at least some data I can massage into it?

FWIW I'm using ASP.NET Core 3.1, with the default System.Text.Json (not JSON.NET).

Edit: Removed spurious notes about PostgreSQL which turned out to be irrelevant to the question.

Have you installed and configured the NodaTime.Serialization.SystemTextJson package? (It's not clear how the database is involved here - I'd expect this to be reproducible without anything to do with the database, at which point your question could be simplified.) — Jon Skeet, Sep 09 '20 at 14:27
@JonSkeet You are quite right. I didn't realize that I was looking at a previous version of the NodaTime user guide (from a Google search), and therefore couldn't find any reference to System.Text.Json serialization. Smooth on my part. Thanks for the lead. — k3davis, Sep 09 '20 at 15:29
Cool. If you've got it working now, you might want to just add an answer. — Jon Skeet, Sep 09 '20 at 15:42

score 17 · Accepted Answer · answered Sep 09 '20 at 15:53

I was able to resolve this with an assist noted in the comments, by installing the NodaTime.Serialization.SystemTextJson package and adding this to my Startup.cs:

services.AddControllers()
    // the added bit:
    .AddJsonOptions(opt => opt.JsonSerializerOptions.ConfigureForNodaTime(DateTimeZoneProviders.Tzdb));

I had to reverse-engineer this from other uses found on github since I was looking at the wrong version of the userguide for NodaTime like a doofus. Cheers.

Deserializing NodaTime Instant from System.Text.Json

1 Answers1