Deserializing JSON Array (C# / JsonFx)

I'm working with JsonFx to serialize some data but I get: "JsonTypeCoercionException: Only objects with default constructors can be deserialized. (Level[])" when I try to deserialize the data.

I've tried adding a default constructor to the serialized class but I still get the error. Fwiw, I tried the different suggestions in a similar thread:
http://forum.unity3d.com/threads/117256-C-deserialize-JSON-array

Here's my code:

Code (csharp):

1.  
2.  
3. //C#
4. using System;
5. using UnityEngine;
6. using System.Collections;
7. using JsonFx.Json;
8. using System.IO;
9.  
10. public class LoadLevel : MonoBehaviour {
11.    
12.    
13.     string _levelFile = "levels.json";
14.     Level[] _levels;
15.    
16.     void Start () {
17.                
18.         if (!File.Exists (_levelFile)){
19.                                
20.             // write an example entry so we have somethng to read
21.             StreamWriter sw = File.CreateText(_levelFile);
22.            
23.             Level firstLevel = new Level();
24.             firstLevel.LevelName = "First Level";              
25.             firstLevel.Id = Guid.NewGuid().ToString();
26.            
27.    
28.             sw.Write(JsonFx.Json.JsonWriter.Serialize(firstLevel));
29.             sw.Close();
30.            
31.         }
32.        
33.            
34.         // Load our levels
35.         if(File.Exists(_levelFile)){
36.        
37.             StreamReader sr = File.OpenText(_levelFile);
38.                    
39.             _levels = JsonReader.Deserialize<Level[]>(sr.ReadToEnd());
40.  
41.         }
42.                    
43.     }
44. }
45.  
46.  

And here's the object it's serializing:

Code (csharp):

1.  
2. using UnityEngine;
3. using System.Collections;
4. using System;
5.  
6. public class Level {
7.    
8.     public string Id;
9.     public string LevelName;
10.    
11.     public Level() {}
12.    
13. //  public string Id { get; set;}
14. //  public string LevelName { get; set; }
15. // 
16. // 
17. }
18.  
19.  
20.  

Any ideas?

 

Not sure if this is the only issue but it does look like you are serializing a single `Level` object and then trying to read back an `Array` of `Level` objects. These two would serialize differently in JSON and it is probably having trouble trying to coerce an object into an Array class.

 

Thanks but that wasn't it. I added a second item and had the same issue. So weird.

 

You got to leave all the serialization to JsonFx, and save the end result. Then, when you load the saved result and deserialize it with using JsonFx, it will work.

(noticed you are writing a single object, but should write the array instead - if reading it as array later)

Similar thread in the case of further questions.

 

Where did you add the second level?

The first level you created isn't being added to a level array either.

Code (csharp):

1.  
2. Level firstLevel = new Level();
3. firstLevel.levelName = "myLevelName";
4. firstLevel.id = "myLevelID";
5.  
6. Level[] myLevels = new Level[1];
7. myLevels[0] = firstLevel;
8.  
9. JsonFx.Json.JsonWriter.Serialize(myLevels);
10.  
11. Level[] DS_Levels = JsonReader.Deserialize<Level[]>(myLevels);
12.  

I can't know much without you posting your new code, but I think you're serializing each level individually, which will have a different structure than an array of Levels.

 

I've been using jsonfx 1.4 in my game for a couple months and it has been working great, but sometime in the last couple weeks it has totally broken on iOS. I wish I knew exactly when but I expect it is whenever the last Unity version came out, which was a couple weeks ago IIRC.

It still works fine in the editor but on iOS it fails when trying to deserialize (serialization still works) ints, uints, or floats. Strings still work.

I know it's not my game code because I made a really simple test project with only the jsonfx dll file and a single script to test it. You can test serialization / deserialization of data structures with ints, uints, floats, and strings. Every test fails except for the string test.

Is anyone still using jsonfx successfully on iOS with the latest Unity?

I uploaded a very simple test project so you guys can easily test jsonfx with your version of Unity + iOS.
https://github.com/tayl0r/jsonfxV1-UnityTest

If anyone still has the version of Unity before Unity 4.01f2 I would really appreciate if you could give that project a test to see if it runs on your iOS device.

 

solved: http://forum.unity3d.com/threads/136720-Json.Net-iPhone-compatibility?p=1167573#post1167573