How to query multiple json nodes? - c#

I have the following json:
{
"key445" : {
"text" : "cat",
"id" : 445
},
"key457" : {
"text" : "mouse",
"id" : 457
},
"key458" : {
"text" : "rodent",
"id" : 458
}
}
I am trying extract text and id into a List<TextIdentifier> (a class with string and an int), or even separately into List<string> and List<int>.
I read the text into JObject using JObject.Parse method. However, I can't figure out how to get to the text and id nodes. I've tried the following but it returns nothing.
var textTokens = o.SelectTokens("/*/text");
var idTokens = o.SelectTokens("/*/id");
How can I get to the tokens I want?

I would just convert the whole JSON into a Dictionary<string, TextIdentifier> instead of trying to use JsonPath at all:
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
public class TextIdentifier
{
public string Text { get; set; }
public int Id { get; set; }
public override string ToString() => $"Id: {Id}; Text: {Text}";
}
public class Test
{
static void Main()
{
var json = File.ReadAllText("test.json");
var dictionary = JsonConvert.DeserializeObject<Dictionary<string, TextIdentifier>>(json);
foreach (var pair in dictionary)
{
Console.WriteLine($"{pair.Key} => {pair.Value}");
}
}
}
Output:
key445 => Id: 445; Text: cat
key457 => Id: 457; Text: mouse
key458 => Id: 458; Text: rodent
If you don't care about the keys, you can use dictionary.Values.ToList() to get a List<TextIdentifier> although you shouldn't rely on the order of them.

Related

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.

Parse JSON Objects with unique strings as parents using JSON.Net

Let's say I have this example JSON:
"Test": {
"KIf42N7OJIke57Dj6dkh": {
"name": "test 1"
},
"xsQMe4WWMu19qdULspve": {
"name": "test 2"
}
}
I want to parse this into an Array of a custom class I have, which will be exampled below:
class Class1 {
public string Name { get; set; }
Class1(string name) {
Name = name;
}
}
How can I parse this using Json.NET's JObject.Parse?
You can achieve your goal with JPath query like this :
var myArray = JObject
.Parse(json)
.SelectTokens("$.Test..name")
.Values<string>()
.Select(s => new Class1(s))
.ToArray();
But probably not the best way to do it.
I personnaly prefere to create classes to represent the json structure and then apply transformations.
void Main()
{
var json = #"{""Test"": {
""KIf42N7OJIke57Dj6dkh"": {
""name"": ""test 1""
},
""xsQMe4WWMu19qdULspve"": {
""name"": ""test 2""
}
}
}";
var root = JsonConvert.DeserializeObject<Root>(json);
var array = root.Test.Select(i => i.Value).ToArray();
array.Dump();
}
public class Root
{
public Dictionary<string, Class1> Test { get; set; }
}
public class Class1
{
public string Name { get; set; }
public Class1(string name)
{
Name = name;
}
}
To begin with, your Json is missing starting/closing braces. The Json needs to have wrapping braces around the Test value.
{
'Test':
{
'KIf42N7OJIke57Dj6dkh': {'name': 'test 1'},
'xsQMe4WWMu19qdULspve': {'name': 'test 2'}
}
}
If you are missing it in the original Json, you could wrap the current input Json as following.
var correctedJson = $"{{{inputJsonString}}}";
If you want to parse the Json Objects to Array of Class1 without creating additional concrete data structures and using JPath Queries, you could use Anonymous Types for the purpose using the DeserializeAnonymousType Method proved by Json.Net. For example,
var sampleObject = new {Test = new Dictionary<string,Class1>()};
var data = JsonConvert.DeserializeAnonymousType(correctedJson,sampleObject);
var result = data.Test.Select(x=>x.Value).ToArray();
You could also achieve it using JPath Query or creating Concrete Data Structures as #Kalten as described in his answer.

How to iterate through JObject Properties via Foreach/LINQ

I have an established JObject object. Trying to loop through it to acquire a Key/value based on anothers Key/value (example of json below with code currently stuck on)
For a tad more detail - looking to loop through "value", get the "KeyID" based on "MailState"
definitely feel like I am missing the step of filtering by MailState/ColName apparently - I have searched through threads a bunch but if someone knows of one that answered this that i was unable to find i will happily pull this down/reference it
// JSON DATA
{
"odata.metadata": "https://..com/odata/$metadata#JCJMCDXes",
"value": [
{
"KeyID": "10379",
"MailCity": "Chicago",
"MailState": "IL"
},
{
"KeyID": "9846",
"MailCity": "Chicago",
"MailState": "IL"
},
{
"KeyID": "2234",
"MailCity": "Madison",
"MailState": "WI"
}]
}
// Current code example
// class in play
public class datastorage
{
public string ID { get; set; }
public string Col { get; set; }
}
public class listData
{
public string ColName {get;set;}
}
// getVPData is a string response from a call to an API
getVPData.Replace(System.Environment.NewLine, "");
JObject jobj = (JObject)Newtonsoft.Json.JsonConvert.DeserializeObject(getVPData);
List<datastorage> data = new List<datastorage>();
// Loop
foreach(var r in listData) // has distinct State abeviations so only 1 occurence
{
foreach (var j in jobj) // This the right path?
{
//add KeyID into ID
data.add(new datastorage
{
ID = ,//add KeyID into ID
Col = r.ColName
});
}
}
You can use Newtonsoft.Json library to parse and loop to the items of value
here is a sample code:
dynamic json = JsonConvert.DeserializeObject(getVPData);
foreach (dynamic item in json["value"])
{
//you can access the fields inside value.
var KeyID = item["KeyID"];
var MailCity = item["MailCity"];
var MailState = item["MailState"];
//just for showing...
Console.WriteLine("KeyID:{0}, MailCity:{1}, MailState:{2}", KeyID, MailCity, MailState);
}
Let me know if the snippet works.
Straightforward ways are:
using System;
using System.Linq;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
namespace ConsoleApp7
{
internal class Program
{
private static void Main(string[] args)
{
var mailStates = new[] {"IL", "WI"};
var jObject = (JObject) JsonConvert.DeserializeObject(json);
var values = (JArray) jObject["value"];
// 1st way
foreach (var mailState in mailStates)
{
var key = values
.Where(v => mailState == v.SelectToken("MailState").Value<string>())
.Select(v => v.Value<string>("KeyID"))
.FirstOrDefault();
Console.WriteLine($"1st case: {mailState} - {key}");
}
/* 2nd way based on JSONPath
* api: https://www.newtonsoft.com/json/help/html/QueryJsonSelectTokenJsonPath.htm
* dox: https://support.smartbear.com/alertsite/docs/monitors/api/endpoint/jsonpath.html
* tester: https://jsonpath.curiousconcept.com/
*/
foreach (var mailState in mailStates)
{
var key = values.SelectTokens($"$[?(#.MailState == '{mailState}')].KeyID")
.Select(v => v.ToString())
.FirstOrDefault();
Console.WriteLine($"2nd case: {mailState} - {key}");
}
Console.ReadKey();
}
private static string json = #"
{
""odata.metadata"": ""https://cdxapiclient.palmercg.com/odata/$metadata#JCJMCDXes"",
""value"": [
{
""KeyID"": ""10379"",
""MailCity"": ""Chicago"",
""MailState"": ""IL""
},
{
""KeyID"": ""9846"",
""MailCity"": ""Chicago"",
""MailState"": ""IL""
},
{
""KeyID"": ""2234"",
""MailCity"": ""Madison"",
""MailState"": ""WI""
}]
}";
}
}

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