I have to extract a part of json-string using .net or newtonsoft json.
JSON:
var json = "{\"method\":\"subtract\",\"parameters\":{\"minuend\":\"SOME_CUSTOM_JSON_OBJECT_DIFFERENT_FOR_EACH_METHOD\",\"subtrahend\":23}}";
C# Class:
class MyJson{
public string method { get; set; }
//public string parameters {get; set;}
public object parameters {get; set;}
}
I do not need to parse all the children of "parameters" json-object. "parameters" could be a very big object ([{obj1}...{obj1000}], objX of 1000 fields), parse which would be not performant.
I would like i.e. to pass it exactly as it is on some point, so conversion "string-C#object-string" would be redundant.
I do not want use Regexp or string transformations (string.Substring, Split and co), because of error margin, I know that all .net and newtonsoft string transformations based.
Question 1: if I define a property of type "object", how newtonsoft will handle this? (Documentation is worse than msdn, so I'm looking for the input from you, who already tried this).
static void Main(string[] args)
{
var json = "{\"method\":\"subtract\",\"parameters\":{\"minuend\":42,\"subtrahend\":23}}";
var data = JsonConvert.DeserializeObject<MyJson>(j);
// what internal representaion of data.parameters?
// How is it actually converted from json-string to an C# object (JObject/JsonObject).
}
In perfect case:
"parameters" is a string and calling
ExtractMyJson(jsonString)
gives me the json string of parameters.
Basically I need the newtonsoft version of
string ExtractMyJson(jsonString){
var p1 = jsonString.Split(",");
// .. varios string transformations
return pParams;
}
Note: please don't reference "dynamic" keyword or ask why no string transformations, it's the very specific question.
If you know that your parameters are unique you can do something like this:
class MyJson
{
public string method { get; set; }
public Dictionary<string,object> parameters { get; set; }
}
................
string json = "{\"method\":\"subtract\",\"parameters\":{\"minuend\":{\"img\": 3, \"real\": 4},\"subtrahend\":23}}";
var data = JsonConvert.DeserializeObject<MyJson>(json);
If you let it as object is going to receive the type Newtonsoft.Json.Linq.JObject.
Have you tried JTOKEN?
It is a rather simple solution to partially read basic or nested JSONs as described in this post.
For a nested JSON
{
"key1": {
"key11": "value11",
"key12": "value12"
}
"key2": "value2"
}
it would look like this
JToken token = JToken.Parse(json);
var value12 = token.SelectToken("key1.key12");
to get the element of the key "key12.
I think this could go nicely with your problem.
Well Objects are treated the same way your parent object is treated. It will start from the base of the graph. So if you have something like:
Person
{
Address Address {get;set;}
}
The Json will start Deserializing Address and then add in the Person object.
If you want to limit thesize of the graph depth you can use a setting like :
JsonConvert.DeserializeObject<List<IList<IList<string>>>>(json, new JsonSerializerSettings
{
MaxDepth = 2
});
For more configurations of the JsonSerializer check JsonSerializerSettings
If your field is an object then that object will have the KeyValuePair of every property that it holds, based on that when you cast that field you can access that type.(the behaviour is the same as assigning a type to an object in C#).
Update: So if you question using JsonObject or type, well JObject is and intermediary way to construct the json format in a generic format. But using the Type deserializatin means you can ignore properties you are not interested in. Mapping to a json with a type makes more sense because it creates a new object and dismisses the old JObject.
Related
I want to convert something like this this {\"ref\":\"/my/path\",\"action\":\"set\",\"payload\":\"\"}
into a generic object in C#. What i tried is this
object mess1 = JObject.Parse(message);
dynamic mess2 = JsonConvert.DeserializeObject<object>(message);
dynamic mess3 = JValue.Parse(message);
The expected result would be an object with the properties ref, action and set. The actual result is an object containing the JObject
ChildrenTokens
Count
First
HasValues
Last
Next
Parent
...
these are not part of my object. What is the correct way of doing this?
The payload in this message is a string OR an arbitrary object. The payload is to be written to a database and i do not care what it contains.
JObject.Parse generates a JObject instance. You can do this a couple of ways, if you already have JObject, you can do the following:
var obj = JObject.Parse(json);
var command = obj.ToObject<Command>();
Or, you can work from the string:
var command = JsonConvert.Deserialize<Command>(json);
We generally use
this method
public static JObject JsonParsed(string Json)
{
return JObject.Parse(Json);
}
You can deserialize it into a dynamic object with:
dynamic parsed = JObject.Parse("ref\":\"/my/path\",\"action\":\"set\",\"payload\":\"\");
And access your properties like any other object:
Console.WriteLine(parsed.ref); // "/my/path/"
Console.WriteLine(parsed.action); // "set"
Console.WriteLine(parsed.payload); // "\"
By "object with my properties" you mean what's often referred as POCO.
You have to define a POCO object like so:
public class Poco
{
public string Ref { get; set; }
public string Action { get; set; }
public string Payload { get; set; }
}
Then deserialize your JSON like so:
string json = "{'ref':'/my/path','action':'set','payload':''}";
Poco myPoco = JsonConvert.DeserializeObject<Poco>(json);
Now you will have myPoco.Ref, myPoco.Action, myPoco.Payload properties populated from your JSON.
Currently I am using the YouTube API to get some data. The data is in json and I am trying to get a single part of it.
The problem that I am facing right now is that I want to use the following method:
WebClient client = new WebClient();
string jsonData = client.DownloadString("https://www.googleapis.com/youtube/v3/videos?id=" + videoId + "&part=contentDetails&key=");
var results = JsonConvert.DeserializeObject(jsonData);
string duration = results["items"]["contentDetails"]["duration"];
Currently this results in an error:
Cannot apply indexing with [] to an expression of type 'object'
The problem I am facing right now is that I don't know how to deserialize the object properly so I can use text indexes to get to the data. I used to do it like this before but I can't recall it and can't find anything about my method.
What you should do is define a class with all your properties that matches your JSON, and then pass that class as a type argument to the deserialization:
Results results = JsonConvert.DeserializeObject<Results>(jsonData);
I don't have more info about your JSON, but a quick definition would look like this:
public class Results
{
public Items items { get; set; }
}
public class Items
{
public ContentDetails contentDetails { get; set; }
}
public class ContentDetails
{
public string duration { get; set; }
}
If you need help converting a JSON response to C# classes, you can use converters such as http://json2csharp.com/
You can also deserialize to a dynamic type, like so:
var results = JsonConvert.DeserializeObject<dynamic>(jsonData);
Then, you just access your properties:
string duration = results.items.contentDetails.duration;
However, using dynamic is not recommended most of the time, because it effectively removes static typing, so you must be sure that duration will be a string, or it will throw a runtime exception when you try to access it.
Normally if I'm dealing with a JSON payload that I don't feel like mapping to a strong type I use JObjects which allow for LINQ to JSON.
var jObject = JObject.Parse(jsonString);
This will allow the properties of the object to be indexed using [] syntax.
More information on using LINQ to JSON in the API docs.
Get your Deserialized data into dynamic type:
dynamic results = JsonConvert.DeserializeObject(jsonData);
and then access it using .:
string duration = results.items.contentDetails.duration;
The syntax you're using is used in javascript.
Try this way:
dynamic results = JsonConvert.DeserializeObject(jsonData);
then you can do
string duration = results["items"]["contentDetails"]["duration"];
or
string duration = results.items.contentDetails.duration;
Reference to dynamic keyword on MSDN: https://msdn.microsoft.com/en-us/library/dd264736.aspx
While trying to de-serialize a complex JSON object (JIRA issue) into an object containing a dictionary of type string-Field I've hit a bit of a bump.
While I can de-serialize various pre-determined object types (standard), I'm having a bit of a harder time with the custom fields, which could be of various types (they all begin with customfield_ followed by a set of numbers).
The custom fields can be floats, strings, booleans, objects and arrays of objects. The latter of these is causing me issues since I can't seem to determine what the object is before I de-serialize it.
I've searched for a way to perhaps "peek" at the data in the object before de-serializing as one of the fields contains information specific to it's type. This is all so I can determine the type of the object and tell Json.Net what to de-serialize it as.
I've considered parsing the JSON string before serialization to get the information, or maybe just when hitting this particular case, but maybe there is a better way?
Thanks in advance for any advice on this.
You can deserialize to an object with Json.Net. Here's a quick and dirty example:
using System;
using Newtonsoft.Json;
namespace Sandbox
{
class Program
{
private static void Main(string[] args)
{
var nestDto = new Dto
{
customfield_1 = 20,
customfield_2 = "Test2"
};
var dto = new Dto
{
customfield_1 = 10,
customfield_3 = new[] { nestDto },
customfield_2 = "Test"
};
var jsonString = JsonConvert.SerializeObject(dto);
Console.WriteLine(jsonString);
var fromJsonString = JsonConvert.DeserializeObject<Dto>(jsonString);
Console.WriteLine(fromJsonString.customfield_3[0].customfield_2); //Outputs Test2
Console.ReadKey();
}
}
class Dto
{
public int customfield_1 { get; set; }
public string customfield_2 { get; set; }
public Dto[] customfield_3 { get; set; }
}
}
Instead of peaking, you can deserialize as the same type as JSON.net uses for ExtensionData explicitly. For example:
if (reader.TokenType == JsonToken.StartArray)
{
var values = serializer.Deserialize<List<Dictionary<string, JToken>>>(reader);
objectContainer = ClassifyAndReturn(values);
}
private ObjectType ClassifyAndReturn(List<Dictionary<string, JToken>> values)
{
if (values.First().ContainsKey("self"))
{
string self = values.First()["self"].Value<string>();
if (self.Contains("customFieldOption"))
//... Then go into a series of if else cases to determine the object.
The representation of the objects are given as a Dictionary of string to JToken, which can then easily be checked and assigned manually or in some cases automatically deserialized (in the case one of the fields is another object).
Here is what an object constructor could look like:
internal myobject(Dictionary<string, JToken> source)
{
Self = source["self"].Value<string>();
Id = source["id"].Value<string>();
Value = source["value"].Value<string>();
}
I'm really bad with C# and would like your help doing the following; I am currently passing a Json Array to my WCF webservice. I need to take the json array and insert it into a list. I have no idea to deserialize in C#. Please suggest to me what is the best way of achieving this. My code looks as follows:
public String UpdateOrderAddress(Stream userInfo)
{
try
{
StreamReader reader = new StreamReader(userInfo);
string JSONdata = reader.ReadToEnd();
if (JSONdata == null)
{
return "null";
}
return JSONdata; // Success !
}
catch (Exception e)
{
return e.ToString();
}
}
This is the data in the string that I get from the reader
[{"date":"2013-02-22 15:30:374:021","id":"1","description":"test","name":"test"},
"date":"2013-02-25 11:56:926:020","id":"2","description":"ghy","name":"fhh"},
"date":"2013-02-25 11:56:248:026","id":"3","description":"ghfm","name":"run"}]
The code you posted doesn't show how are you trying to deserialize your json string so I don't really follow what's the relevance here but in any case, this is how to deserialize JSON into a concrete C# class.
Create a class that matches the structure of your Javascript objects as so:
public class Data
{
public string Date {get;set;}
public int ID {get;set;}
public string Description {get;set;}
public string Name {get;set;}
}
Deserialize it using the JavascriptSerializer as so:
var deserializedData = new JavaScriptSerializer().Deserialize<List<Data>>(jsonString);
Note that your original JSON string is incorrectly formatted. It's missing the opening { on each element of the array. It should really be:
[{"date":"2013-02-22
15:30:374:021","id":"1","description":"test","name":"test"},
{"date":"2013-02-25
11:56:926:020","id":"2","description":"ghy","name":"fhh"},
{"date":"2013-02-25
11:56:248:026","id":"3","description":"ghfm","name":"run"}]
Now, if you attempt to deserialize the above, as so:
string json = #"[{""date"":""2013-02-22 15:30:374:021"",""id"":""1"",""description"":""test"",""name"":""test""},
{""date"":""2013-02-25 11:56:926:020"",""id"":""2"",""description"":""ghy"",""name"":""fhh""},
{""date"":""2013-02-25 11:56:248:026"",""id"":""3"",""description"":""ghfm"",""name"":""run""}]";
var deserializedData = new JavaScriptSerializer().Deserialize<List<Data>>(json);
You'll get a nice List<Data> back.
Also note that I didn't use a DateTime field for the corresponding date field in your Javascript object, the reason being that your sample dates are not valid DateTimes or at least a DateTime object cannot be created from that string representation. For instance, "15:30:374:021" makes no sense - I would imagine that 374 is the seconds field...
You need to add a reference to System.Web.Extensions to be able to use the JavascriptSerializer.
You can create a representative class with your required properties to hold the values and use the JavascriptSerializer class. Call the Deserialize<T> method specifying your type to deserialize the JSON into your code.
Links in class names for reference.
You can use Newtonsoft.Json Library. All you will need to do is:
List<YourClass> yourClassList = JsonConvert.DeserializeObject<List<YourClass>>(JSONdata);
You find more information, even samples here
I'm recieving a JSON object that looks like the example below.
{
"name1":{"name1a":"value1a","name1b":"value1b"},
"name2":{"name2a":"value2a","name2b":"value2b"}
}
I've set up a data contract for it (since I only need to access a single data field at the moment) like this.
[DataContract]
public class MyThingy
{
[DataMember(Name="name1b")]
public string Name1b { get; set; }
public MyThingy() { }
public MyThingy(String name1b)
{
Name1b = name1b;
}
}
When I've serialized the object, I try to print it out (which works, since I'm getting a string description of the class) and them the field Name1b. The last part doesn't work and I'm getting null there. My guess is that I must have mapped the data contract wrongly but I can't see how to correct it.
How should the MyThingy class be declared?
My JSON object is fetched as described in this post.
I would use JavaScriptSerializer here,
string json = #"{
""name1"":{""name1a"":""value1a"",""name1b"":""value1b""},
""name2"":{""name2a"":""value2a"",""name2b"":""value2b""}
}";
var obj = new JavaScriptSerializer()
.Deserialize<Dictionary<string, Dictionary<string, string>>>(json);
Console.WriteLine(obj["name1"]["name1b"]);
You can also use Json.Net and dynamic together
dynamic obj = JsonConvert.DeserializeObject(json);
Console.WriteLine(obj.name1.name1b);