UTC Date is being deserialized to server local time when PUT and PATCH.

Question

User1649945628 posted

When I sending data in a HTTP Request with POST method, any date string formatted like "2016-02-05T15:00:00.000Z" is deserialized  correctly as UTC date time at the server side. But with PUT or PATCH method, it will deserialize it as local date time. It extremely annoying when I using ODATA v4 $Patch method sending POST/PUT/PATCH in a same batch and need to twist the date time in order to workaround the bug.

I noticed that someone had complain about the GET method long ago.

Can someone comment on the issue?

Thanks in advance!

Richard.

Answer 1

User1814019480 posted

hi rtang,

I wonder know how do you parse your date string on server side?

I guess you may need use the DateTimeOffset method or SpecifyKind method. The similar thread about this issue , please refer to it:

http://stackoverflow.com/questions/3188933/prevent-timezone-conversion-on-deserialization-of-datetime-value

Regards,

Will

Answer 2

User1649945628 posted

Hi will,

I'm sending the data in JSON format. From the server side I'm not doing any manual de-serialization.  It's very hard for me to change all DateTime properties to DateTimeOffset at this stage. The controllers are derived from ODataController. When I sending the same Date Time data to POST or PUT,  it's de-serialized with different value. For example, the following two methods get different Date information even when the same data were sent:

[System.Web.Http.HttpPost]
public IHttpActionResult Post([FromBody] Category category)
{
    //category.UpdateDate is correct;
}

[System.Web.Http.HttpPut]
public IHttpActionResult Put([FromODataUri] int id, [FromBody] Category category)
{
  //category.UpdateDate is incorrect;
}

Answer 3

User36583972 posted

Hi rtang2011,

From your description, I suggest you can customize CustomJsonMediaTypeFormatter class. Through this you can correctly handle type, to ensure data consistency before and after.

The following code for your reference.

CustomJsonMediaTypeFormatter:

public class CustomJsonMediaTypeFormatter : MediaTypeFormatter
    {
        public JsonSerializerSettings _jsonSerializerSettings;
        public CustomJsonMediaTypeFormatter()
        {
            _jsonSerializerSettings = CustomJsonSettings.Instance;
            // Fill out the mediatype and encoding we support
            SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/json"));
            SupportedEncodings.Add(new UTF8Encoding(false, true));
        }
        public override bool CanReadType(Type type)
        {
            return true;
        }
        public override bool CanWriteType(Type type)
        {
            return true;
        }
        public override Task<object> ReadFromStreamAsync(Type type, Stream stream, HttpContent content, IFormatterLogger formatterLogger)
        {
            // Create a serializer
            Newtonsoft.Json.JsonSerializer serializer = Newtonsoft.Json.JsonSerializer.Create(_jsonSerializerSettings);
            // Create task reading the content
            return Task.Factory.StartNew(() =>
            {
                using (StreamReader streamReader = new StreamReader(stream, SupportedEncodings.First()))
                {
                    using (JsonTextReader jsonTextReader = new JsonTextReader(streamReader))
                    {
                        return serializer.Deserialize(jsonTextReader, type);
                    }
                }
            });
        }
        public override Task WriteToStreamAsync(Type type, object value, Stream stream, HttpContent content, TransportContext transportContext)
        {
            // Create a serializer
            Newtonsoft.Json.JsonSerializer serializer = Newtonsoft.Json.JsonSerializer.Create(_jsonSerializerSettings);
            // Create task writing the serialized content
            return Task.Factory.StartNew(() =>
            {
                using (StreamWriter streamWriter = new StreamWriter(stream, SupportedEncodings.First()))
                {
                    using (JsonTextWriter jsonTextWriter = new JsonTextWriter(streamWriter))
                    {
                        serializer.Serialize(jsonTextWriter, value);
                    }
                }
            });

        }

    }


    public static class CustomJsonSettings
    {
        private static JsonSerializerSettings _settings;
        public static JsonSerializerSettings Instance
        {
            get
            {
                if (_settings == null)
                {
                    var settings = new JsonSerializerSettings();
                    // Must convert times coming from the client (always in UTC) to local - need both these parts:
                    JsonSerializerSettings serializerSettings = new JsonSerializerSettings();
                    settings.Converters.Add(new IsoDateTimeConverter { DateTimeStyles = System.Globalization.DateTimeStyles.AssumeUniversal }); // Critical part 1
                    settings.DateTimeZoneHandling = DateTimeZoneHandling.Local; // Critical part 2
                                                                                // Skip circular references
                    settings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
                    // Handle special cases in json (self-referencing loops, etc)
                    //settings.ContractResolver = new CustomJsonResolver();
                    _settings = settings;
                }
                return _settings;
            }
        }
    }

WebApiConfig:

public static void Register(HttpConfiguration config)
        {
            GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.JsonFormatter);
            GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);
            GlobalConfiguration.Configuration.Formatters.Add(new CustomJsonMediaTypeFormatter());

            ODataModelBuilder builder = new ODataConventionModelBuilder();
            builder.EntitySet<Category>("Category");
            config.MapODataServiceRoute(
                routeName: "ODataRoute",
                routePrefix: "odata",
                model: builder.GetEdmModel());
        }

The tutorial about Using JSON.NET with ASP.NET Web API in the below:

https://code.msdn.microsoft.com/Using-JSONNET-with-ASPNET-b2423706

Best Regards,

Yohann Lu