MINIJson Unity get nested json objects

Question

{ "check":"success", "stats":{ "2":{ "rank":1, "score":"2000", "name":"Muhammad" }, "3":{ "rank":1, "score":"2000", "name":"Ramsay" }}}

this is my json string. I want to use "stats" as a list to check how many entries it has. Then I need to get the rank, name, score etc from each entry. My code is,

var result = Json.Deserialize(jsontest) as Dictionary<string,object>;
    object st;
    var rankholders = new List<object>();
    if (result.TryGetValue("stats", out st))
    {
        rankholders = (List<object>)(((Dictionary<string, object>)st)["stats"]);
        foreach (object obj in rankholders)
        {
            var tempDict = ((Dictionary<string,object>)(rankholders[0]));
            WeeklyStatsItem tempRow = new WeeklyStatsItem ();
            tempRow.rank = (string)tempDict["rank"];
            tempRow.name = (string)tempDict["name"];
            tempRow.score = (string)tempDict["score"];
            weeklyScoreList.Add (tempRow);
        }
    }

But I get keynotfound exception. Any idea how to parse such a json loop?

Answer 1

To me it looks like you have an object which contains a property "check" and a dictionary called "stats". If you will make your own class having this structure, you will be able to deserialize json to this type of object Something like:

class Stats
{
public int rank;
public int score;
public string name;
}

class ResultContainer
{
public string checked;
public Dictionary<int,Stats>stats;
}

And you should deserialize as ResultContainer.

Answer 2

Your Json is NOT valid because it was throwing error when stats is made to be a List or array. I was able to re-create a valid Json with the code below:

I want to use "stats" as a list to check how many entries it has

WeeklyStatsItem recreation = new WeeklyStatsItem();
recreation.check = "success";

recreation.stats = new List<Stats>();

Stats st1 = new Stats();
st1.rank = 1;
st1.score = "2000";
st1.name = "Muhammad";
recreation.stats.Add(st1);

Stats st2 = new Stats();
st2.rank = 1;
st2.score = "2000";
st2.name = "Ramsay";
recreation.stats.Add(st2);

Debug.Log(JsonUtility.ToJson(recreation));

The new generated valid Json is:

{"check":"success","stats":[{"rank":1,"score":"2000","name":"Muhammad"},{"rank":1,"score":"2000","name":"Ramsay"}]}

Now to answer your question:

I want to use "stats" as a list to check how many entries it has.

string jsonTest = "{\"check\":\"success\",\"stats\":[{\"rank\":1,\"score\":\"2000\",\"name\":\"Muhammad\"},{\"rank\":1,\"score\":\"2000\",\"name\":\"Ramsay\"}]}";
WeeklyStatsItem weeklyIt = JsonUtility.FromJson<WeeklyStatsItem>(jsonTest);
Debug.Log(weeklyIt.stats.Count);

Then I need to get the rank, name, score etc from each entry

string jsonTest = "{\"check\":\"success\",\"stats\":[{\"rank\":1,\"score\":\"2000\",\"name\":\"Muhammad\"},{\"rank\":1,\"score\":\"2000\",\"name\":\"Ramsay\"}]}";
WeeklyStatsItem weeklyIt = JsonUtility.FromJson<WeeklyStatsItem>(jsonTest);

Debug.Log("CHECK: " + weeklyIt.check);
for (int i = 0; i < weeklyIt.stats.Count; i++)
{
    Debug.Log("STATS INDEX: " + i);
    Debug.Log("RANK: " + weeklyIt.stats[i].rank);
    Debug.Log("NAME: " + weeklyIt.stats[i].name);
    Debug.Log("SCORE: " + weeklyIt.stats[i].score);
}

Your Json Classes:

[Serializable]
public class Stats
{
    public int rank;
    public string score;
    public string name;
}

[Serializable]
public class WeeklyStatsItem
{
    public string check;
    public List<Stats> stats;
}

Answer 3

Since you're keys have semantic meaning and don't map to variable names you'll have to go a bit further than the basic examples that assume your json objects map neatly to a c# object, i.e. that they have a fixed schema.

Basically you'll have to look at each entry in the stats dict and pass both the key and the underlying values to your domain object constructor.

I'm not super familiar with MiniJSON, but I've banged together a working example. I suspect there is a more idiomatic way of doing this, e.g. using generics.

Assets/Editor/ParserTest.cs

using NUnit.Framework;

public class ParserTest {

    [Test]
    public void TestThatTwoPlayersAreInTestResponse()
    {
        string testResponse = "{ \"check\":\"success\", \"stats\":{ \"2\":{ \"rank\":1, \"score\":\"2000\", \"name\":\"Muhammad\" }, \"3\":{ \"rank\":1, \"score\":\"2000\", \"name\":\"Ramsay\" } } }";
        Assert.AreEqual(MiniJsonParsingExample.parseResponse(testResponse).Count, 2);
    }
}

Assets/Scripts/MiniJsonParsingExample.cs

using System.Collections.Generic;
using Facebook.MiniJSON;

public class MiniJsonParsingExample
{

    public static List parseResponse(string responseText)
    {
        var resultDict = Json.Deserialize(responseText) as Dictionary;
        var players = new List();
        if (resultDict.ContainsKey("stats"))
        {
            var playerDict = resultDict["stats"] as Dictionary;
            foreach (string playerId in playerDict.Keys)
            {
                var psuedoPlayer = playerDict[playerId] as Dictionary;
                string playerName = psuedoPlayer["name"] as string;
                long playerRank = (long) psuedoPlayer["rank"];
                string playerScore = psuedoPlayer["score"] as string;
                players.Add(new Player(playerId, playerName, playerRank, playerScore));
            }
        }
        return players;
    }

    public class Player
    {
        string id;
        string name;
        long rank;
        string score;

        public Player(string id, string name, long rank, string score)
        {
            this.id = id;
            this.name = name;
            this.rank = rank;
            this.score = score;
        }
    }
}