How to access Json data without unknown key?

Question

public static string RESTToJsonConverter(string incoming_data){
    string data = "[";
    int i = 0;
    Debug.Log("incoming_data"+incoming_data);
    data += "]";
    string JSONToParse = "{\"values\":" + data + "}";
    return JSONToParse;
}

Below is my result when I run that code. My Question is how can I access/get all the data without taking "M4qRmfIqhKdy643Ujye" key (auto-generate)?

If using JavaScript, I can use object.values but since I'm using C#, I don't know how to get the data.

{
    "-M4qRmfIqhKdy643Ujye": {
        "assetName": "avatar",
        "id": "-M4qRmfnFya7bC43Ujye",
        "imageName": "icon_avatar",
        "name": "Bob",
        "objName": "Bobby",
        "point": "-M4vZRY9vhKs65n5L_Gk",
        "versionNumber": "3"
    },
    "-M4qRmfIqhKdy643Ujye": {
        "assetName": "avatar",
        "id": "-M4qRmfnFya7bC43Ujye",
        "imageName": "icon_avatar",
        "name": "Bobfds",
        "objName": "Bobbydsf",
        "point": "-M4vZRY9vhKs65n5L_Gk",
        "versionNumber": "3"
    },
    "-M4qRmfIqhKdy643Ujye": {
        "assetName": "avatar",
        "id": "-M4qRmfnFya7bC43Ujye",
        "imageName": "icon_avatar",
        "name": "Bobfdsa",
        "objName": "Bobbyfc",
        "point": "-M4vZRY9vhKs65n5L_Gk",
        "versionNumber": "3"
    }

}

UPDATE

This is one of function in my Downloader Class

IEnumerator DownloadData(string dataPath, Action<string> callback){
    Debug.Log("dataPath=>"+dataPath);
    var token = LocalData.getAuth();
    Auth data = JsonUtility.FromJson<Auth>(token);
    var request = new 
    UnityWebRequest("https://test123.firebaseio.com/"+dataPath+".json? 
    auth="+data.idToken, "GET");
    request.downloadHandler = (DownloadHandler) new 
    DownloadHandlerBuffer();
    request.SetRequestHeader("Content-Type", "application/json");

    yield return request.SendWebRequest();

    if (request.isHttpError || request.isNetworkError)
    {
        Debug.Log(request.error);
        NotificationHelper.showOnePopup("Error \n"+request.error);
        callback(null);
    }
    else
    {
        //Debug.Log(request.downloadHandler.text);
        string json = 
        FirebaseSetup.RESTToJsonConverter(request.downloadHandler.text);
        callback(json);
    }

Below is my FirebaseSetup Class

public static string FirebaseToJsonConverter(DataSnapshot snapshot){
    string data = "[";
    int i = 0;
    foreach(DataSnapshot s in snapshot.Children){
        data += s.GetRawJsonValue();
        i++;
        if(i != snapshot.ChildrenCount)
            data += ",";
    }
    data += "]";
    string JSONToParse = "{\"values\":" + data + "}";
    return JSONToParse;
}

public static string RESTToJsonConverter(string incoming_data)
{
    Debug.Log($"incoming_data:/n{incoming_data}");

    // remove everything before the SECOND occurrence of '{'
    // remove last occurrence of '}'
    var startIndex = incoming_data.IndexOf('{', incoming_data.IndexOf('{') + 1);
    var endIndex = incoming_data.LastIndexOf('}') - 1;
    var json = incoming_data.Substring(startIndex, endIndex - startIndex);

    // then remove leading or trailing whitespace
    json = json.Trim();
    
    Debug.Log($"json:/n{json}");

    var data = JsonUtility.FromJson<string>(json);

    return data;
}

After I try @derHugo code, I get new error.

This is my new error

When you researched "*deserialize json C#*" what did you have trouble with ? — TheGeneral, Sep 07 '20 at 04:01
@MichaelRandall I think this question relates to [Get properties and values from unknown object](https://stackoverflow.com/questions/4144778/get-properties-and-values-from-unknown-object) — Tân, Sep 07 '20 at 04:12

derHugo · Accepted Answer · 2020-09-08T05:57:22.590

For your specific case I would go the other way round:

The root field name usually doesn't matter so if you remove the trailing } and start the string from the second { you would have

{
    "assetName": "avatar",
    "id": "-M4qRmfnFya7bC43Ujye",
    "imageName": "icon_avatar",
    "name": "Bob",
    "objName": "Bobby",
    "point": "-M4vZRY9vhKs65n5L_Gk",
    "versionNumber": "3"
}

which you can simply create a c# class for

[Serializable]
public class Data
{
    public string assetName;
    public string id;
    public string imageName;
    public string name;
    public string objName;
    public string point;
    public string versionNumber;
}

and then you could use JsonUtility

public static Data RESTToJsonConverter(string incoming_data)
{
    Debug.Log($"incoming_data:/n{incoming_data}");

    // remove everything before the SECOND occurrence of '{'
    // remove last occurrence of '}'
    var startIndex = incoming_data.IndexOf('{', incoming_data.IndexOf('{') + 1);
    var endIndex = incoming_data.LastIndexOf('}') - 1;
    var json = incoming_data.Substring(startIndex, endIndex - startIndex);

    // then remove leading or trailing whitespace
    json = json.Trim();
    
    Debug.Log($"json:/n{json}");
   
    var data = JsonUtility.FromJson<Data>(json);

    return data;
}

Update

You now updated your question content so now the data comes as a Dictionary of data objects.

In this case you could use Newtonsoft Json.NET which directly supports (de)serialization of Dictionary like e.g.

[Serializable]
public class Data
{
    public string assetName;
    public string id;
    public string imageName;
    public string name;
    public string objName;
    public string point;
    public string versionNumber;
}

and then do something like

public static Dictionary<string, Data> RESTToJsonConverter(string incoming_data)
{
    Debug.Log($"incoming_data:/n{incoming_data}");
   
    var data = JsonConvert.DeserializeObject<Dictionary<string, Data>(json);

    return data;
}

then you can do e.g.

var datas = RESTToJsonConverter(receivedRawData);
foreach(var data in data.Values)
{
    Debug.Log(data.id);
}

score 0 · Answer 2 · answered Sep 07 '20 at 11:46

I suppose, your question is about the deserialization of the JSON with non-unique keys. If it is, take to look over here: How to deserialize JSON with duplicate property names in the same object

In your case, the solution should contain the following:

declaring your contract:

public class Data
{
        public string assetName{get;set;}
        public string id{get;set;}
        public string imageName{get;set;}
        public string name{get;set;}
        public string objName{get;set;}
        public string point{get;set;}
        public string versionNumber{get;set;}
}

your "custom deserializer" :)

public static JToken DeserializeAndCombineDuplicates(JsonTextReader reader)
{
    if (reader.TokenType == JsonToken.None)
    {
        reader.Read();
    }

    if (reader.TokenType == JsonToken.StartObject)
    {
        reader.Read();
        JObject obj = new JObject();
        while (reader.TokenType != JsonToken.EndObject)
        {
            string propName = (string)reader.Value;
            reader.Read();
            JToken newValue = DeserializeAndCombineDuplicates(reader);

            JToken existingValue = obj[propName];
            if (existingValue == null)
            {
                obj.Add(new JProperty(propName, newValue));
            }
            else if (existingValue.Type == JTokenType.Array)
            {
                CombineWithArray((JArray)existingValue, newValue);
            }
            else // Convert existing non-array property value to an array
            {
                JProperty prop = (JProperty)existingValue.Parent;
                JArray array = new JArray();
                prop.Value = array;
                array.Add(existingValue);
                CombineWithArray(array, newValue);
            }

            reader.Read();
        }
        return obj;
    }

    if (reader.TokenType == JsonToken.StartArray)
    {
        reader.Read();
        JArray array = new JArray();
        while (reader.TokenType != JsonToken.EndArray)
        {
            array.Add(DeserializeAndCombineDuplicates(reader));
            reader.Read();
        }
        return array;
    }

    return new JValue(reader.Value);
}   
private static void CombineWithArray(JArray array, JToken value)
{
    if (value.Type == JTokenType.Array)
    {
        foreach (JToken child in value.Children())
            array.Add(child);
    }
    else
    {
        array.Add(value);
    }
}

some code to get a Dictionary<string, Data[]> as a result type

using (StringReader sr = new StringReader(json))
using (JsonTextReader reader = new JsonTextReader(sr))
{
    var parsed = DeserializeAndCombineDuplicates(reader).ToObject<Dictionary<string, Data[]>>();
    
    if(parsed!=null)
    {
        parsed
            .ToList()
            .ForEach(x=>Console.WriteLine("\r\nkey={0}\r\nvalues:\r\n{1}"
                                , x.Key
                                , string.Join("\r\n", x.Value
                                              .Select(z=>string.Join("\t\t", z.name, z.id, z.objName))
                                              .ToArray())));
    } else Console.WriteLine("No way, dude!");
}

The full solution is placed here: https://dotnetfiddle.net/lYBytk

How to access Json data without unknown key?

2 Answers2

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