Develop Reference

Query nested JSON with LINQ

I have the following JSON:
{
"rooms": [
{
"roomId": 1,
"lightsPreset": [
{
"lightsPresetId": 1,
"loadValues": [ 1, 2, 3 ]
},
{
"lightsPresetId": 2,
"loadValues": [ 11, 12, 13 ]
}]
},
{
"roomId": 2,
"lightsPreset": [
{
"lightsPresetId": 1,
"loadValues": [ 21, 22, 23 ]
},
{
"lightsPresetId": 2,
"loadValues": [ 211, 212, 213 ]
}]
}
]
}
and I need to get loadValues out of it (say roomId = 1 and lightsPresetId = 1)
I managed to do it using JSONPath
IEnumerable<JToken> loadValues = o.SelectTokens("$.rooms[?(#.roomId == 1)].lightsPreset[?(#.lightsPresetId == 1)].loadValues[*]");
but my goal is to make it work in .Net Framework 3.5 where JSONPath didn't work.
Trying this with LINQ gives me everything for roomId = 1, but I can't figure out how to query nested arrays.
JObject o = JObject.Parse(rawJson);
var itemList = from values in o["rooms"].Children()
where (decimal)values["roomId"] == 1
select values;
Thank you.

On a PC now, so I can post it up as an answer rather than comment from the phone
If you visit https://quicktype.io you can use it to generate classes from your JSON:
// <auto-generated />
//
// To parse this JSON data, add NuGet 'Newtonsoft.Json' then do:
//
// using SomeNamespace;
//
// var someRootClassName = SomeRootClassName.FromJson(jsonString);
namespace SomeNamespace
{
using System;
using System.Collections.Generic;
using System.Globalization;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
public partial class SomeRootClassName
{
[JsonProperty("rooms")]
public List<Room> Rooms { get; set; }
}
public partial class Room
{
[JsonProperty("roomId")]
public long RoomId { get; set; }
[JsonProperty("lightsPreset")]
public List<LightsPreset> LightsPresets { get; set; }
}
public partial class LightsPreset
{
[JsonProperty("lightsPresetId")]
public long LightsPresetId { get; set; }
[JsonProperty("loadValues")]
public List<long> LoadValues { get; set; }
}
public partial class SomeRootClassName
{
public static SomeRootClassName FromJson(string json) => JsonConvert.DeserializeObject<SomeRootClassName>(json, SomeNamespace.Converter.Settings);
}
public static class Serialize
{
public static string ToJson(this SomeRootClassName self) => JsonConvert.SerializeObject(self, SomeNamespace.Converter.Settings);
}
internal static class Converter
{
public static readonly JsonSerializerSettings Settings = new JsonSerializerSettings
{
MetadataPropertyHandling = MetadataPropertyHandling.Ignore,
DateParseHandling = DateParseHandling.None,
Converters =
{
new IsoDateTimeConverter { DateTimeStyles = DateTimeStyles.AssumeUniversal }
},
};
}
}
Then you can convert your JSON to objects like this:
var root = SomeRootClassName.FromJson(rawJson);
And you can query it like:
var array = root.Rooms.First(r => r.RoomId == 1).LightsPresets.First(lp => lp.LightsPresetId == 1).LoadValues;
Or if those IDs might not exist:
var array = root.Rooms.FirstOrDefault(r => r.RoomId == 1)?.LightsPresets.First(lp => lp.LightsPresetId == 1)?.LoadValues;
if(array != null) ....
When working with LINQ, it helps to make sure that anything that is a collection/array has a plural name. Then you can easily know whether you can just access a property of it (if it's singular) or have to use some method like First, Last, Single, Any, Where etc, if it has a plural name:
root.Rooms //plural, collection
.First(r => r.RoomId == 1) //.First on a plural results in a singular, a room object
.LightsPresets //access a plural property of the single room above
.First(lp => lp.LightsPresetId == 1) //first lightpresent in many LightPresets in the room
.LoadValues //plural again; it's an array. The LINQ query resolves to an array output
Give your lambda arguments sensible names too - don't use x for everything; i used r for "a room in the collection of rooms", and lp for "a lightpreset in the collection of lightpresets"

try this
var rooms = (JArray) JObject.Parse(json)["rooms"];
var roomId=1;
var lightsPresetId =1;
int[] values = rooms.Where(r => (int)r["roomId"] == roomId)
.Select(r=> r["lightsPreset"]).FirstOrDefault()
.FirstOrDefault(x => (int)x["lightsPresetId"] == lightsPresetId)["loadValues"]
.ToObject<int[]>().ToArray();

Get the value of the Key from a Json Array

I have the below Json Array and I need to get the value of the key inside my "relation" object. How do I do that? The relation object has different set of key-value pair for each object in the array.
[
{
"data": {
"_hash": null,
"kind": "ENTITY",
"id": "test122",
"payload": {
"attributes": {
"bbl:27": false
},
"relations": {
"bbl:45": "P18",
"bbl:P18": "P562"
},
"type": [
"P185"
]
}
}
}
]
In above inside relations the keys are "bbl:45" and "bbl:P18". I need these values, in specific I need to extract 45 and P18, considering bbl remain constant inside relation object. how do i do it. There are multiple objects in the Jarray, I have shown only one.

I would mention, if you can change data format, consider doing so, having payload as part as a member proper name is highly unusual but you could do like this:
[Fact]
public void DynamicJsonHandlingTest()
{
var serialized = "[{\"data\":{\"_hash\":null,\"kind\":\"ENTITY\",\"id\":\"test122\",\"payload\":{\"attributes\":{\"bbl:27\":false},\"relations\":{\"bbl:45\":\"P18\",\"bbl:P18\":\"P562\"},\"type\":[\"P185\"]}}}]";
using var jDoc = JsonDocument.Parse(serialized);
var enumerator = jDoc.RootElement.EnumerateArray();
foreach(var JsonElement in enumerator)
{
var relationsElement = JsonElement.GetProperty("data").GetProperty("payload").GetProperty("relations");
foreach (var ele in relationsElement.EnumerateObject())
{
var sought = ele.Name.Split(":")[1];
//sought now cointains first 45 then P18
}
}
}

The following Code solves your problem.
using Newtonsoft.Json.Linq;
using System;
using System.Linq;
using Json.Net;
namespace ConsoleApp1
{
class Program
{
static void Main(string[] args)
{
string json = "{\"data\":{\"_hash\":null,\"kind\":\"ENTITY\",\"id\":\"test122\",\"payload\":{\"attributes\":{\"bbl:27\":false},\"relations\":{\"bbl:45\":\"P18\",\"bbl:P18\":\"P562\"},\"type\":[\"P185\"]}}}";
JObject jsonObject = JObject.Parse(json);
var results = jsonObject["data"]["payload"]["relations"];
foreach (var item in results)
{
string propName = ((JProperty)item).Name;
string requiredValue = propName.Split(':')[1];
Console.WriteLine($"Required: {requiredValue} !");
}
}
}
}
You should add some error handling when the property name does not contains :

For dynamic keys you can use dictionary:
public class Root
{
public Data data { get; set; }
}
public class Data
{
public Payload payload { get; set; }
}
public class Payload
{
public Dictionary<string, string> relations { get; set; }
}
var result = JsonConvert.DeserializeObject<List<Root>>(sourcejson);
And then next will contain all keys:
var keys = result
.Select(r => r.data)
.Select(r => r.payload)
.SelectMany(r => r.relations.Keys)
Or use the LINQ to JSON API:
var result = JsonConvert.DeserializeObject<JArray>(sourcejson);
var list = result
.Children()
.SelectMany(c => c["data"]["payload"]["relations"].Children<JProperty>())
.Select(p => p.Name)
.ToList(); // list is {"bbl:45", "bbl:P18"}
And then you can process the keys as you need - for example using Split(':') to turn "bbl:45" into array of "bbl" and `"45".

Deserializing JSON with numbers as field using JsonSerializer

I need to deserialize this weird JSON (image below). I've seen some deserialization hints using Dictionary<>, etc. but the problem is that "parameters" contains different data, then previous keys.
Can I somehow get it to work using JsonSerializer deserializator without doing foreach loops and other suspicious implementations? I do need data from "data" in my application.
Here's some of my code:
using var client = new WebClient();
var json = client.DownloadString(GetJsonString());
var invoicesData = JsonSerializer.Deserialize<JsonMyData>(json, options);
If using Newtonsoft is necessary I might start using it.

With Newtonsoft you can parse and access arbitrary JSON documents, even ones that can't reasonably be deserialized into a .NET object. So something like:
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
namespace ConsoleApp35
{
class Program
{
static void Main(string[] args)
{
var json = #"
{
""myData"" :
{
""0"" : { ""data"": { ""A"":1,""B"":2} },
""1"" : { ""data"": { ""A"":1,""B"":2} },
""2"" : { ""data"": { ""A"":1,""B"":2} },
""3"" : { ""data"": { ""A"":1,""B"":2} },
""parameters"" : { ""p"":""a""}
},
""status"":{ }
}";
var foo = JObject.Parse(json);
var a = foo["myData"]["1"]["data"];
Console.WriteLine(a);
Console.WriteLine("Hit any key to continue");
Console.ReadKey();
}
}
}

I think you should really consider using Newtonsoft.Json instead of default JsonDeserializer, it is much easier to use in such situations.

If you are interested in processing this without foreach loops and wanting to access the data in a list format, I would suggest using Dictionary for this. When you use dictionary, you can use Objects as values that would compensate for differences in numbers (0, 1, 2, ..) and words (parameters).
// Classes to Deserialize data we need.
public class MyObject
{
[JsonProperty("data")]
public Data Data { get; set; }
}
public class Data
{
public int A { get; set; }
public int B { get; set; }
}
Usage in Main
// Read in the JSON
var myData = JsonConvert.DeserializeObject<dynamic>(jsonString)["myData"];
// Convert To Dictionary
Dictionary<string, dynamic> dataAsObjects = myData.ToObject<Dictionary<string, dynamic>>();
string searchFor = "3";
dataAsObjects.TryGetValue(searchFor, out dynamic obj);
if (obj != null)
{
// Conversion to int and matching against searchFor is to ensure its a number.
int.TryParse(searchFor, out int result);
if (result == 0 && result.ToString().Equals(searchFor))
{
MyObject myObject = obj.ToObject<MyObject>();
Console.WriteLine($"A:{myObject.Data.A} - B:{myObject.Data.B}");
}
else if (result == 8 && result.ToString().Equals(searchFor))
{
// I am not clear on whats your parameters class look like.
MyParameters myParams = obj.ToObject<MyParameters>();
}
}
Output
A:1 - B:2
With this method you can either access the numbers or the parameters element.

NewtonSoft json parsing

Can somebody help me to parse the json and get the details.
Lets say i have Top2 input parameter as Police and i want to know the respective Top3 and in that Top3 array i need to check whether Test1Child value is there or not.
I am using newtonsoft json + c# and so far i can get till DeviceTypes using below code
var json = File.ReadAllText(jsonFile); // below json is stored in file jsonFile
var jObject = JObject.Parse(json);
JArray MappingArray =(JArray)jObject["Top1"];
string strTop1 = ObjZone.Top1.ToString();
string strTop2 = ObjZone.Top2.ToString();
var JToken = MappingArray.Where(obj => obj["Top2"].Value<string>() == strTop2).ToList();
//Json
{
"Top1": [
{
"Top2": "Test1",
"Top3": [
"Test1Child"
]
},
{
"Top2": "Test2",
"Top3": [
"Test2Child"
]
}
]
}

I'd use http://json2csharp.com/ (or any other json to c# parser) and then use C# objects (it's just easier for me)
This would look like that for this case:
namespace jsonTests
{
public class DeviceTypeWithResponseTypeMapper
{
public string DeviceType { get; set; }
public List<string> ResponseTypes { get; set; }
}
public class RootObject
{
public List<DeviceTypeWithResponseTypeMapper> DeviceTypeWithResponseTypeMapper { get; set; }
}
}
and the use it like that in code:
var rootob = Newtonsoft.Json.JsonConvert.DeserializeObject<RootObject>(str);
var thoseThatHaveNotUsed = rootob.DeviceTypeWithResponseTypeMapper.Where(dtwrtm =>
dtwrtm.ResponseTypes.Any(rt => rt == "NotUsed"));
foreach (var one in thoseThatHaveNotUsed)
{
Console.WriteLine(one.DeviceType);
}
this code lists all the Device types that have "NotUsed" among the responses.
version 2 (extending your code) would look like that, i believe:
static void Main(string[] args)
{
var json = str; // below json is stored in file jsonFile
var jObject = JObject.Parse(json);
JArray ZoneMappingArray = (JArray)jObject["DeviceTypeWithResponseTypeMapper"];
string strDeviceType = "Police";
string strResponseType = "NotUsed";
var JToken = ZoneMappingArray.Where(obj => obj["DeviceType"].Value<string>() == strDeviceType).ToList();
var isrespTypeThere = JToken[0].Last().Values().Any(x => x.Value<string>() == strResponseType);
Console.WriteLine($"Does {strDeviceType} have response type with value {strResponseType}? {yesorno(isrespTypeThere)}");
}
private static object yesorno(bool isrespTypeThere)
{
if (isrespTypeThere)
{
return "yes!";
}
else
{
return "no :(";
}
}
result:
and if you'd like to list all devices that have response type equal to wanted you can use this code:
var allWithResponseType = ZoneMappingArray.Where(jt => jt.Last().Values().Any(x => x.Value<string>() == strResponseType));
foreach (var item in allWithResponseType)
{
Console.WriteLine(item["DeviceType"].Value<string>());
}

Howto C# DeserializeObject, where variable name is number?

How do I Deserialize the following. The problem is that the variable name is a number. So how should MyClass be defined?
json_str:
{"23521952": {"b": [], "o": []}, "23521953": {"b": [], "o": []}}
class MyClass { //? };
var var = JsonConvert.DeserializeObject<MyClass>(json_str);

This sounds like the outer object is actually a dictionary:
using System.Collections.Generic;
using Newtonsoft.Json;
class Foo
{
// no clue what b+o look like from the question; modify to suit
public int[] b { get; set; }
public string[] o { get; set; }
}
static class P
{
static void Main()
{
var json = #"{""23521952"": {""b"": [], ""o"": []}, ""23521953"": {""b"": [], ""o"": []}}";
var obj = JsonConvert.DeserializeObject<Dictionary<string, Foo>>(json);
foreach(var pair in obj)
{
System.Console.WriteLine($"{pair.Key}, {pair.Value}");
}
}
}

You can use anonymous type deserialization for your data like this, without creating classes for properties of JSON. Hope it works.
var finalResult=JsonConvert.DeserializeAnonymousType(
json_str, // input
new
{
Id=
{
new
{
b=new[], o=new[]
}
}
}
);
foreach(var id in finalResult.Id)
{
console.write(id); // gives ids like 23521952
console.write(id.b[0]) // gives first elemnt in 'b' array
}