C#•4d ago

Newtonsoft Json not deserializing with some property/constructor names

Hi, I'm using newtonsoft json to serialize and deserialize my classes. Everything works perfect until I put the name ID, Identifier, UniqueIdentifier anywhere in my class or Constructor which is to be deserialized. For example:

    public class Command
    {
        public string UniqueID { get; set; }
        public float PositionX { get; set; }
        public float PositionY { get; set; }
        public float PositionZ { get; set; }

        public Command(string id, Vector3 position)
        {
            PositionX = position.x;
            PositionY = position.y;
            PositionZ = position.z;

            UniqueID = id;
        }
    }

    public class Command
    {
        public string UniqueID { get; set; }
        public float PositionX { get; set; }
        public float PositionY { get; set; }
        public float PositionZ { get; set; }

        public Command(string id, Vector3 position)
        {
            PositionX = position.x;
            PositionY = position.y;
            PositionZ = position.z;

            UniqueID = id;
        }
    }

This serializes perfectly but when I try to deserialize it, the Identifier is null. If I change the name to something else, for example key It will work and deserialize perfectly... Anyone knows the reason for it? Here's what I receive and try to deserialize:

{
    "PositionX":7.63098526,
    "PositionY":15.25,
    "PositionZ":12.0,
    "RotationX":0.0,
    "RotationY":0.0,
    "RotationZ":0.0,
    "RotationW":1.0,
    "UniqueID":"40dd0008-bc4c-4988-a9f9-835f6a0c2ac9"
}

{
    "PositionX":7.63098526,
    "PositionY":15.25,
    "PositionZ":12.0,
    "RotationX":0.0,
    "RotationY":0.0,
    "RotationZ":0.0,
    "RotationW":1.0,
    "UniqueID":"40dd0008-bc4c-4988-a9f9-835f6a0c2ac9"
}

And here's how I'm deserializing it:

        public static T Deserialize(string json)
        {
            try
            {
                if (string.IsNullOrEmpty(json))
                {
                    Debug.LogError("Cannot deserialize null or empty JSON.");
                    return null;
                }

                return JsonConvert.DeserializeObject<T>(json);
            }
            catch (Exception ex)
            {
                Debug.LogError($"Deserialization failed: {ex.Message}");
                return null;
            }
        }

        public static T Deserialize(string json)
        {
            try
            {
                if (string.IsNullOrEmpty(json))
                {
                    Debug.LogError("Cannot deserialize null or empty JSON.");
                    return null;
                }

                return JsonConvert.DeserializeObject<T>(json);
            }
            catch (Exception ex)
            {
                Debug.LogError($"Deserialization failed: {ex.Message}");
                return null;
            }
        }

If anyone have any good explanation for it, please let me know.

29 Replies

Keswiik•4d ago

probably need a default constructor for newtonsoft to use

Ras GullaOP•4d ago

Any specific explanation for it? Since position and rotation is perfectly deserialized just that id is null...

Angius•4d ago

Any particular reason you're using Newtonsoft in the first place, btw?

Ras GullaOP•4d ago

To Serialize and Deserialize for sending over the network... 🤔

Angius•4d ago

Yeah, but .NET has built-in Json serialization now Unless you're using an old version of the framework or something

Ras GullaOP•4d ago

I can't change it now, I've published 13 Minigames with this, changing it now would be a headache

Angius•4d ago

Ah, it's Unity?

Ras GullaOP•4d ago

Yes

Angius•4d ago

Then it falls under "old version of the framework" Carry on

Ras GullaOP•4d ago

😅

Pobiega•4d ago

Your constructor parameters are named differently from your properties, and there is no parameterless constructor

Adam Vincent•4d ago

yup, serializers like System.Text.Json and JSON.Net are looking for a public parameter-less constructor https://stackoverflow.com/questions/23017716/json-net-how-to-deserialize-without-using-the-default-constructor

Stack Overflow

JSON.net: how to deserialize without using the default constructor?

I have a class that has a default constructor and also an overloaded constructor that takes in a set of parameters. These parameters match to fields on the object and are assigned on construction....

Ras GullaOP•4d ago

So just adding a empty constructor would fix the problem? What about position, rotation? They are being deserialized as intended...

Pobiega•4d ago

respectfully, that aint true

 public class Command
    {
        public string UniqueID { get; set; }
        public float PositionX { get; set; }
        public float PositionY { get; set; }
        public float PositionZ { get; set; }

        public Command(string id, Vector3 position)
        {
            PositionX = position.x;
            PositionY = position.y;
            PositionZ = position.z;

            UniqueID = id;
        }
    }

 public class Command
    {
        public string UniqueID { get; set; }
        public float PositionX { get; set; }
        public float PositionY { get; set; }
        public float PositionZ { get; set; }

        public Command(string id, Vector3 position)
        {
            PositionX = position.x;
            PositionY = position.y;
            PositionZ = position.z;

            UniqueID = id;
        }
    }

there are no properties or fields here for rotation so it cant possibly deserialize properly

Ras GullaOP•4d ago

It was an example I just write in Discord, Lemme show the actual class:

Pobiega•4d ago

assuming all your properties have public setters, it should be fine with a blank parameterless constructor, yes

Ras GullaOP•4d ago

    public class TrashUpdateCommand : BaseCommand<TrashUpdateCommand>
    {
        public float PositionX { get; set; }
        public float PositionY { get; set; }
        public float PositionZ { get; set; }

        public float RotationX { get; set; }
        public float RotationY { get; set; }
        public float RotationZ { get; set; }
        public float RotationW { get; set; }

        public string Key { get; private set; }

        public TrashUpdateCommand(string Key, Vector3 position, Quaternion rotation)
        {
            this.Key = Key;

            PositionX = position.x;
            PositionY = position.y;
            PositionZ = position.z;

            RotationX = rotation.x;
            RotationY = rotation.y;
            RotationZ = rotation.z;
            RotationW = rotation.w;
        }
        public Vector3 GetPosition()
        {
            return new Vector3(PositionX, PositionY, PositionZ);
        }
        public Quaternion GetRotation()
        {
            return new Quaternion(RotationX, RotationY, RotationZ, RotationW);
        }
    }

    public class TrashUpdateCommand : BaseCommand<TrashUpdateCommand>
    {
        public float PositionX { get; set; }
        public float PositionY { get; set; }
        public float PositionZ { get; set; }

        public float RotationX { get; set; }
        public float RotationY { get; set; }
        public float RotationZ { get; set; }
        public float RotationW { get; set; }

        public string Key { get; private set; }

        public TrashUpdateCommand(string Key, Vector3 position, Quaternion rotation)
        {
            this.Key = Key;

            PositionX = position.x;
            PositionY = position.y;
            PositionZ = position.z;

            RotationX = rotation.x;
            RotationY = rotation.y;
            RotationZ = rotation.z;
            RotationW = rotation.w;
        }
        public Vector3 GetPosition()
        {
            return new Vector3(PositionX, PositionY, PositionZ);
        }
        public Quaternion GetRotation()
        {
            return new Quaternion(RotationX, RotationY, RotationZ, RotationW);
        }
    }

Adam Vincent•4d ago

or you can specify the constructor with the JsonConstructorAttribute

Ras GullaOP•4d ago

I've changed the name to key here because it was working 😅 I was actually trying to find the answer for this behaviour. I didn't find any answer for it on google that if we name our properties like this, it won't work.

Adam Vincent•4d ago

If you changed

public string Key { get; private set; }

public string Key { get; private set; }

public string key { get; private set; } //lower case property name

public string key { get; private set; } //lower case property name

then you might be looking for CamelCasePropertyNamesContractResolver

Pobiega•4d ago

private set isnt the same as set thats why Key isnt deserializing properly if it worked, its because your constructor takes a key parameter and newtonsoft figures out that probably maps to the Key property

Ras GullaOP•4d ago

Hmmm, I'll try this. I guess I tried it with public setter too. I'll come again with more data : )

Adam Vincent•4d ago

If you have a really good reason why Key is private set you can use PrivateSetterContractResolver(), to deserilize privates

Pobiega•4d ago

with a public setter and a parameterless constructor, I see no reason why this shouldnt work

Ras GullaOP•4d ago

No, don't have any reason for it. I guess I Just accidently set it private while I was trying different things to find any answer

Adam Vincent•4d ago

been there. Auto-complete will do that to ya.

Ras GullaOP•4d ago

Yeah : ) I'll try it again. I'm sure it didn't work with public setter too. Will come here after confirming 🙂 Anyways, Thank You!

Honza K.•4d ago

IMO all you had to do was place [JsonProperty("UniqueID")] on the constructor id parameter 😄

Ras GullaOP•4d ago

Could workaround but wanted to know "Why" 😅 Guys I just confirmed, it was an issue with constructor and had nothing to do with name as I was thinking. This worked perfectly fine:

    public class TestCommand : BaseCommand<TestCommand>
    {
        public string ID { get; set; }
        public int UniqueID { get; set; }
        public int SomeNumber { get; set; }

        public TestCommand(int number, int uid, string id)
        {
            ID = id;
            UniqueID = uid;
            SomeNumber = number;
        }
    }

    public class TestCommand : BaseCommand<TestCommand>
    {
        public string ID { get; set; }
        public int UniqueID { get; set; }
        public int SomeNumber { get; set; }

        public TestCommand(int number, int uid, string id)
        {
            ID = id;
            UniqueID = uid;
            SomeNumber = number;
        }
    }

Thank You so much 🫶

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Newtonsoft Json not deserializing with some property/constructor names

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