JSON JObject.Parse modifies json string

Question

I have got incomming Json in format:

{
    "Type": "value",
    "Name": "MeteoStation",
    "UniqueAdress": "2C:3A:E8:0F:10:76",
    "valuesList": [{
        "Value": 23.00,
        "Unit": "C",
        "Type": "temperature",
        "SourceUniqAdress": "2C:3A:E8:0F:10:76",
        "TimeCaptured": "2018-03-26T09:36:13.200Z"
    }]
}

In my program, I want to create object IValuePacket that is one value in list of values.

JObject jobject = JObject.Parse(incomingJson);
var settings = new JsonSerializerSettings {
    NullValueHandling = NullValueHandling.Ignore,
    MissingMemberHandling = MissingMemberHandling.Ignore
};
var incommingMessage = JsonConvert.DeserializeObject<MessageEncapsulation>(incomingJson);
string Type = incommingMessage.Type;
string name = incommingMessage.Name;

if (string.IsNullOrWhiteSpace(name))
    name = "no name";

if (Type.ToLower().Equals("value")) {
    var values = JsonConvert.DeserializeObject<List<IValuePacket>>(jobject["valuesList"].ToString());
}

Everything works fine untill I recieved exact this json as mention above. JObject.Parse modifies value TimeCaptured and jobject looks like:

{
"Type": "value",
"Name": "Meteostation",
"UniqueAdress": "2C:3A:E8:0F:10:76",
"valuesList": [{
    "Value": 23.00,
    "Unit": "C",
    "Type": "temperature",
    "SourceUniqAdress": "2C:3A:E8:0F:10:76",
    "TimeCaptured": "2018-03-26T09:36:13.2Z"
}]}

Thats not so much difference, but DateTime.ParseExact(value, "yyyy-MM-ddThh:mm:ss.fffZ", System.Globalization.CultureInfo.InvariantCulture); cannot parse new value. Actually, I am sending 201 ms instead of 200 ms. It works, but I want to have good time for future reasons.

Is there any way how to avoid changing in Json during parsing?

Answer 1

It does not really modify your string, it just parses your date string into DateTime object when you call JObject.Parse. If you do this:

var obj = JObject.Parse(json);
var values = (JArray) obj["valuesList"];
var time = (JValue) values[0]["TimeCaptured"];
Console.WriteLine(time.Value.GetType());

You notice that time.Value is of type DateTime. Then you do this:

JsonConvert.DeserializeObject<List<IValuePacket>>(jobject["valuesList"].ToString());

By doing that you convert valueList back to json, but now TimeCaptured is DateTime and not a string, so that DateTime object is converted to json string using whatever date time format is used by JSON.NET by default.

You can avoid parsing strings that look like dates to .NET DateTime objects by parsing json to JObject like this:

JObject obj;
using (var reader = new JsonTextReader(new StringReader(json))) {
    // DateParseHandling.None is what you need
    reader.DateParseHandling = DateParseHandling.None;
    obj = JObject.Load(reader);
}

Then type of TimeCaptured will be string, as you expect.

Side note: there is no need to convert JToken back to string and then call JsonConvert.Deserialize on that string. Instead, do this:

var values = obj["valuesList"].ToObject<List<IValuePacket>>();