[Fork] [Fork] https://stackoverflow.com/questions/56383331/how-to-iterate-through-a-nested-json-object-in-c | C# Online Compiler

[Fork] [Fork] https://stackoverflow.com/questions/56383331/how-to-iterate-through-a-nested-json-object-in-c by dbc_MinLength

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.Serialization.Formatters;
using System.IO;
using System.Data;
using System.ComponentModel.DataAnnotations;
using System.Globalization;
using System.Reflection;
using System.ComponentModel;
using System.Collections.ObjectModel;

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json.Converters;
using Newtonsoft.Json.Serialization;	

using NUnit.Framework; // Throws NUnit.Framework.AssertionException

    // https://stackoverflow.com/questions/56383331/how-to-iterate-through-a-nested-json-object-in-c#comment99367034_56383331

    // https://stackoverflow.com/questions/56383331/how-to-iterate-through-a-nested-json-object-in-c#comment99367034_56383331

    public abstract partial class KeyItemBase : INotifyPropertyChanged
    {
		public KeyItemBase() : this(null, Enumerable.Empty<KeyItemBase>()) { }

		public KeyItemBase(string key, IEnumerable<KeyItemBase> children)
		{
			this.m_key = key;
			this.m_children = new ObservableCollection<KeyItemBase>(children);
		}

		string m_key;
        public string key 
		{ 
			get { return m_key; }
			set
			{
				m_key = value;
				RaisedOnPropertyChanged("key");
			}
		}

		ObservableCollection<KeyItemBase> m_children;
        public ObservableCollection<KeyItemBase> Children { get { return m_children; } }

    	public event PropertyChangedEventHandler PropertyChanged;

		protected void RaisedOnPropertyChanged(string _PropertyName)
		{
			var changed = PropertyChanged;
			if (changed != null)
			{
				changed(this, new PropertyChangedEventArgs(_PropertyName));
			}
		}
	}

	public abstract partial class KeyItemBase
	{
		// Generate clean JSON on re-serialization.
		public bool ShouldSerializeChildren() { return Children != null && Children.Count > 0; }
	}

	public sealed class KeyItem : KeyItemBase
	{
		// Use for a JSON object with no T_id property.
		// Bind an appropriate SfTreeView.ItemTemplate to this type.
	
		public KeyItem() : base() { }

		public KeyItem(string key, IEnumerable<KeyItemBase> children) : base(key, children) { }
	}

	public class KeyIdItem : KeyItemBase
	{
		// Use for a JSON object with a T_id property.
		// Bind an appropriate SfTreeView.ItemTemplate to this type.
	
		public KeyIdItem() : base() { }

		public KeyIdItem(string key, IEnumerable<KeyItemBase> children, long t_id) : base(key, children) { this.m_id = t_id; }

		long m_id;
        public long T_id 
		{ 
			get { return m_id; }
			set
			{
				m_id = value;
				RaisedOnPropertyChanged("T_id");
			}
		}
	}

	public static class KeyItemFactory
	{
		public static KeyItemBase ToKeyObject(string name, long? id, IEnumerable<KeyItemBase> children)
		{
			if (id == null)
				return new KeyItem(name, children);
			else
				return new KeyIdItem(name, children, id.Value);
		}
		
		public static IEnumerable<KeyItemBase> ToKeyObjects(JToken root)
		{
			return root.TopDescendantsWhere<JObject>(o => true)
				.Select(o => ToKeyObject(((JProperty)o.Parent).Name, (long?)o["T_id"], ToKeyObjects(o)));
		}
	}

    public static partial class JsonExtensions
    {
        /// <summary>
        /// Enumerates through all descendants of the given element, returning the topmost elements that match the given predicate
        /// </summary>
        /// <param name="root"></param>
        /// <param name="filter"></param>
        /// <returns></returns>
        public static IEnumerable<TJToken> TopDescendantsWhere<TJToken>(this JToken root, Func<TJToken, bool> predicate) where TJToken : JToken
        {
            if (predicate == null)
                throw new ArgumentNullException();
            return GetTopDescendantsWhere<TJToken>(root, predicate, false);
        }

        static IEnumerable<TJToken> GetTopDescendantsWhere<TJToken>(JToken root, Func<TJToken, bool> predicate, bool includeSelf) where TJToken : JToken
        {
            if (root == null)
                yield break;
            if (includeSelf)
            {
                var currentOfType = root as TJToken;
                if (currentOfType != null && predicate(currentOfType))
                {
                    yield return currentOfType;
                    yield break;
                }
            }
            var rootContainer = root as JContainer;
            if (rootContainer == null)
                yield break;
            var current = root.First;
            while (current != null)
            {
                var currentOfType = current as TJToken;
                var isMatch = currentOfType != null && predicate(currentOfType);
                if (isMatch)
                    yield return currentOfType;

                // If a match, skip children, but if not, advance to the first child of the current element.
                var next = (isMatch ? null : current.FirstChild());

                if (next == null)
                    // If no first child, get the next sibling of the current element.
                    next = current.Next;

                // If no more siblings, crawl up the list of parents until hitting the root, getting the next sibling of the lowest parent that has more siblings.
                if (next == null)
                {
                    for (var parent = current.Parent; parent != null && parent != root && next == null; parent = parent.Parent)
                    {
                        next = parent.Next;
                    }
                }

                current = next;
            }
        }

        static JToken FirstChild(this JToken token)
        {
            var container = token as JContainer;
            return container == null ? null : container.First;
        }
    }

    class TestClass
    {
        public static void Test()
        {
            var json = GetJson();

            // Strip comments
            var root = JToken.Parse(json);

            var items = new ObservableCollection<KeyItemBase>(KeyItemFactory.ToKeyObjects(root));

			// Now bind items to your ItemsSource
			// https://help.syncfusion.com/cr/cref_files/xamarin/Syncfusion.SfTreeView.XForms~Syncfusion.XForms.TreeView.SfTreeView~ItemsSource.html
			
            var newJson = JsonConvert.SerializeObject(items, Formatting.Indented);

			Console.WriteLine("Output ObservableCollection<KeyObjectBase>: ");
            Console.WriteLine(newJson);
			
			Console.WriteLine("\nInput JSON: ");
			Console.WriteLine(json);
			
			// Assert we have exactly the same sequence of `T_id` integers in the mapped structure as in the original.
			//Assert.IsTrue(JArray.Parse(newJson).SelectTokens("..T_id").Select(i => (long)i).SequenceEqual(root.SelectTokens("..T_id").Select(i => (long)i)));
        }

        static string GetJson()
        {
            var json = @"{
   ""Soccer"":{
      ""T_id"":0,
      ""T_state"":""valid"",
      ""Clubs"":{
         ""ClubA"":{
            ""T_id"":""1"",
            ""T_state"":""Champs""
         },
         ""ClubB"":{
            ""T_id"":""2"",
            ""T_state"":""Runnerups""
         }
      },
      ""Subs"":{
         ""SubA"":{
            ""T_id"":""3"",
            ""T_state"":""Unfit"",
            //this is nested key
            ""SubE"":{
               ""T_id"":""3"",
               ""T_state"":""Unfit""
            }
         }
      },
      ""Subs_Used"":{
         ""SubK"":{
            ""T_id"":""3"",
            ""T_state"":""Unfit""
         }
      }
      //many more nested n-levels   
   }
}";
            return json;
        }
    }

	public class Program
	{
		public static void Main()
		{
			Console.WriteLine("Environment version: " + Environment.Version);
			Console.WriteLine("Json.NET version: " + typeof(JsonSerializer).Assembly.FullName);
			Console.WriteLine();

			try
			{
				TestClass.Test();
			}
			catch (Exception ex)
			{
				Console.WriteLine("Failed with unhandled exception: ");
				Console.WriteLine(ex);
				throw;
			}
		}
	}

​x
 
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.Serialization.Formatters;
using System.IO;
using System.Data;
using System.ComponentModel.DataAnnotations;
using System.Globalization;
using System.Reflection;
using System.ComponentModel;
using System.Collections.ObjectModel;
​
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json.Converters;
using Newtonsoft.Json.Serialization;    
​
using NUnit.Framework; // Throws NUnit.Framework.AssertionException
​
    // https://stackoverflow.com/questions/56383331/how-to-iterate-through-a-nested-json-object-in-c#comment99367034_56383331
​
    // https://stackoverflow.com/questions/56383331/how-to-iterate-through-a-nested-json-object-in-c#comment99367034_56383331
​
    public abstract partial class KeyItemBase : INotifyPropertyChanged
    {
        public KeyItemBase() : this(null, Enumerable.Empty<KeyItemBase>()) { }
​
        public KeyItemBase(string key, IEnumerable<KeyItemBase> children)
        {
            this.m_key = key;
            this.m_children = new ObservableCollection<KeyItemBase>(children);
        }
​
        string m_key;
        public string key 
        { 
            get { return m_key; }
            set
            {
                m_key = value;
                RaisedOnPropertyChanged("key");
            }
        }
​
        ObservableCollection<KeyItemBase> m_children;
        public ObservableCollection<KeyItemBase> Children { get { return m_children; } }
​
        public event PropertyChangedEventHandler PropertyChanged;
​
        protected void RaisedOnPropertyChanged(string _PropertyName)
        {
            var changed = PropertyChanged;
            if (changed != null)
            {
                changed(this, new PropertyChangedEventArgs(_PropertyName));
            }
        }
    }
​
    public abstract partial class KeyItemBase
    {
        // Generate clean JSON on re-serialization.
        public bool ShouldSerializeChildren() { return Children != null && Children.Count > 0; }
    }
​
    public sealed class KeyItem : KeyItemBase
    {
        // Use for a JSON object with no T_id property.
        // Bind an appropriate SfTreeView.ItemTemplate to this type.
    
        public KeyItem() : base() { }
​
        public KeyItem(string key, IEnumerable<KeyItemBase> children) : base(key, children) { }
    }
​
    public class KeyIdItem : KeyItemBase
    {
        // Use for a JSON object with a T_id property.
        // Bind an appropriate SfTreeView.ItemTemplate to this type.
    
        public KeyIdItem() : base() { }
​
        public KeyIdItem(string key, IEnumerable<KeyItemBase> children, long t_id) : base(key, children) { this.m_id = t_id; }
​
        long m_id;
        public long T_id 
        { 
            get { return m_id; }
            set
            {
                m_id = value;
                RaisedOnPropertyChanged("T_id");
            }
        }
    }
​
    public static class KeyItemFactory
    {
        public static KeyItemBase ToKeyObject(string name, long? id, IEnumerable<KeyItemBase> children)
        {
            if (id == null)
                return new KeyItem(name, children);
            else
                return new KeyIdItem(name, children, id.Value);
        }
        
        public static IEnumerable<KeyItemBase> ToKeyObjects(JToken root)
        {
            return root.TopDescendantsWhere<JObject>(o => true)
                .Select(o => ToKeyObject(((JProperty)o.Parent).Name, (long?)o["T_id"], ToKeyObjects(o)));
        }
    }
​
    public static partial class JsonExtensions
    {
        /// <summary>
        /// Enumerates through all descendants of the given element, returning the topmost elements that match the given predicate
        /// </summary>
        /// <param name="root"></param>
        /// <param name="filter"></param>
        /// <returns></returns>
        public static IEnumerable<TJToken> TopDescendantsWhere<TJToken>(this JToken root, Func<TJToken, bool> predicate) where TJToken : JToken
        {
            if (predicate == null)
                throw new ArgumentNullException();
            return GetTopDescendantsWhere<TJToken>(root, predicate, false);
        }
​
        static IEnumerable<TJToken> GetTopDescendantsWhere<TJToken>(JToken root, Func<TJToken, bool> predicate, bool includeSelf) where TJToken : JToken
        {
            if (root == null)
                yield break;
            if (includeSelf)
            {
                var currentOfType = root as TJToken;
                if (currentOfType != null && predicate(currentOfType))
                {
                    yield return currentOfType;
                    yield break;
                }
            }
            var rootContainer = root as JContainer;
            if (rootContainer == null)
                yield break;
            var current = root.First;
            while (current != null)
            {
                var currentOfType = current as TJToken;
                var isMatch = currentOfType != null && predicate(currentOfType);
                if (isMatch)
                    yield return currentOfType;
​
                // If a match, skip children, but if not, advance to the first child of the current element.
                var next = (isMatch ? null : current.FirstChild());
​
                if (next == null)
                    // If no first child, get the next sibling of the current element.
                    next = current.Next;
​
                // If no more siblings, crawl up the list of parents until hitting the root, getting the next sibling of the lowest parent that has more siblings.
                if (next == null)
                {
                    for (var parent = current.Parent; parent != null && parent != root && next == null; parent = parent.Parent)
                    {
                        next = parent.Next;
                    }
                }
​
                current = next;
            }
        }
​
        static JToken FirstChild(this JToken token)
        {
            var container = token as JContainer;
            return container == null ? null : container.First;
        }
    }
​
    class TestClass
    {
        public static void Test()
        {
            var json = GetJson();
​
            // Strip comments
            var root = JToken.Parse(json);
​
            var items = new ObservableCollection<KeyItemBase>(KeyItemFactory.ToKeyObjects(root));
​
            // Now bind items to your ItemsSource
            // https://help.syncfusion.com/cr/cref_files/xamarin/Syncfusion.SfTreeView.XForms~Syncfusion.XForms.TreeView.SfTreeView~ItemsSource.html
            
            var newJson = JsonConvert.SerializeObject(items, Formatting.Indented);
​
            Console.WriteLine("Output ObservableCollection<KeyObjectBase>: ");
            Console.WriteLine(newJson);
            
            Console.WriteLine("\nInput JSON: ");
            Console.WriteLine(json);
            
            // Assert we have exactly the same sequence of `T_id` integers in the mapped structure as in the original.
            //Assert.IsTrue(JArray.Parse(newJson).SelectTokens("..T_id").Select(i => (long)i).SequenceEqual(root.SelectTokens("..T_id").Select(i => (long)i)));
        }
​
        static string GetJson()
        {
            var json = @"{
   ""Soccer"":{
      ""T_id"":0,
      ""T_state"":""valid"",
      ""Clubs"":{
         ""ClubA"":{
            ""T_id"":""1"",
            ""T_state"":""Champs""
         },
         ""ClubB"":{
            ""T_id"":""2"",
            ""T_state"":""Runnerups""
         }
      },
      ""Subs"":{
         ""SubA"":{
            ""T_id"":""3"",
            ""T_state"":""Unfit"",
            //this is nested key
            ""SubE"":{
               ""T_id"":""3"",
               ""T_state"":""Unfit""
            }
         }
      },
      ""Subs_Used"":{
         ""SubK"":{
            ""T_id"":""3"",
            ""T_state"":""Unfit""
         }
      }
      //many more nested n-levels   
   }
}";
            return json;
        }
    }
​
    public class Program
    {
        public static void Main()
        {
            Console.WriteLine("Environment version: " + Environment.Version);
            Console.WriteLine("Json.NET version: " + typeof(JsonSerializer).Assembly.FullName);
            Console.WriteLine();
​
            try
            {
                TestClass.Test();
            }
            catch (Exception ex)
            {
                Console.WriteLine("Failed with unhandled exception: ");
                Console.WriteLine(ex);
                throw;
            }
        }
    }
​

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