Disable DateParseHandling on document deserialization - azure-cosmosdb

Question

We have documents on DocumentDB that store a date on ISO 8601 format. These dates are stored as strings:
{
"CreatedOn": "2016-04-15T14:54:40Z",
"Title": "Some title",
"id": "xxx-xxx-xxxx-xxx-xxx-xxx"
}
We are using the latest Azure DocumentDB SDK (1.7.0) on a WebAPI that uses ASP.NET Core.
The C# class that maps our documents have the "CreatedOn" property as a string.
public class Item
{
public string CreatedOn { get; set; }
public string id { get; set; }
public string Title { get; set; }
}
The problem is that when we read a document and the SDK deserializes it, it tries to convert it to a DateTime and then back to a string. Resulting in:
{
"CreatedOn": "15/04/2016 14:54:40",
"Title": "Some title",
"id": "xxx-xxx-xxxx-xxx-xxx-xxx"
}
What I need is to the SDK to leave the values untouched. I tried setting the default SerializerSettings to avoid the date parsing:
services.AddMvc().AddJsonOptions(opts =>
{
opts.SerializerSettings.DateParseHandling = Newtonsoft.Json.DateParseHandling.None;
});
But it didn't work.
I tried using a JsonConverter attribute but the problem is that on the ReadJson override method, the reader already parsed the string value to a DateTime.
class StringJsonConverter : JsonConverter
{
public override bool CanConvert(Type objectType)
{
return true;
}
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
writer.WriteValue(value.ToString());
}
public override bool CanRead
{
get { return true; }
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
reader.Value <-- already a parsed DateTime
}
}
Any ideas on how to overcome this auto parsing?

Answer 1

JSON serializer settings can now be passed straight to DocumentClient constuctors, which allows for the flexibility you required.

Answer 2

Eventually found a workaround, since the JsonSettings are not accesible at this time, I'm using a JsonConverter:
public class StringJsonConverter : JsonConverter
{
public override bool CanConvert(Type objectType)
{
return true;
}
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
writer.WriteValue(value.ToString());
}
public override bool CanRead
{
get { return true; }
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.ValueType.Equals(typeof(DateTime)))
{
return ((DateTime)reader.Value).ToIso8601Date();
}
if (reader.ValueType.Equals(typeof(DateTimeOffset)))
{
return ((DateTimeOffset)reader.Value).DateTime.ToIso8601Date();
}
return (string)reader.Value;
}
}
With this simple extension:
public static class DateTimeExtensions
{
private const string DateTimeFormat = "{0}-{1}-{2}T{3}:{4}:{5}Z";
public static string ToIso8601Date(this DateTime date)
{
if (date.Equals(DateTime.MinValue))
{
return null;
}
return string.Format(
DateTimeFormat,
date.Year,
PadLeft(date.Month),
PadLeft(date.Day),
PadLeft(date.Hour),
PadLeft(date.Minute),
PadLeft(date.Second));
}
private static string PadLeft(int number)
{
if (number < 10)
{
return string.Format("0{0}", number);
}
return number.ToString(CultureInfo.InvariantCulture);
}
}