Get multiple values on JSON with Json.NET - c#

Is there a function where you can select multiples "nodes" on JSON string?
Sample:
var myJson = #"{
'channel' : 'nine',
'segment' : 'mobile',
'food' : 'pizza'
}";
var myObjectFromJson = JObject.Parse(myJson);
var channelFoodNodes = myObjectFromJson.SelectTokens("channel, food"); //<- This call not works!
Expected result:
{
"channel" : "nine",
"food" : "pizza"
}
Reference:
Querying JSON with SelectToken

First, your code is invalid with the newlines (your string should be a verbatim string if you want to put newlines in it without concatenating, with # in front of it, and quotes replaced by double quotes).
Second, you are trying to invoke SelectTokens() on a string... you need to parse it to a JObject first:
var myJson = JObject.Parse(#"
{
""channel"" : ""nine"",
""segment"" : ""mobile"",
""food"" : ""pizza""
}");
Then myJson is a JObject (and not a string) where you can call SelectTokens() on
HOWEVER, what you want to achieve can't be achieved with JPath (which is what SelectTokens() uses), so you'd be better off parsing the object directly, something like:
var channelFoodNodes = myJson.Children()
.OfType<JProperty>()
.Where(x => new []{ "channel", "food"}.Contains(x.Name));
Then you can construct a new JObject from the resulting enumerable of JProperties:
var newObject = new JObject(channelFoodNodes);
Which will contain your resulting object.
You can see it all in action in this fiddle
If you want to select the properies this way (as you were trying to do with SelectTokens()), you can also build a simple extension method:
public static IEnumerable<JProperty> SelectRootProperties(this JObject obj, params string[] propertyNames)
{
return obj.Children().OfType<JProperty>().Where(x => propertyNames.Contains(x.Name));
}
And call it like:
myObject.SelectRootProperties("channel", "food");
See it in action in this other fiddle
(or you could also make a simple method which gets the input json string and the property names, construct the JObject, parse the properties and return the string of the resulting object, which seems to be what you are asking, but I'll leave that as an exercise)

Your existing data is a key/value of strings. You can deserialize it to a Dictionary<string, string> and access the pieces you want from the dictionary produced.
var things = JsonConvert.DeserializeObject<Dictionary<string,string>>(json);
Console.WriteLine(things["channel"]);
Console.WriteLine(things["food"]);

Related

Get Key Name from nested json object

I am new to C# and JSON and need some help in getting the Key name(s) in a list of a nested JSON object. The keys are dynamic so I won't necessarily know the keys.
sample code I've tried.
```
protected void test()
{
var mystring = #"{
""zone1"": {
""sites"": {
""site1"": {
""to"": ""email1"",
""subject"": ""subjecttxt"",
""link"": ""somesite""
},
""site2"": {
""to"": ""email1"",
""subject"": ""subject"",
""link"": ""somesite""
}
},
""zone2"": {
""to"": ""email1"",
""subject"": ""subject"",
""link"": ""somelink""
}}";
var rss = JObject.Parse(mystring);
foreach (var section in rss)
{
Console.Write(section.Key);
IList<JToken> result = rss["zone1"]["sites"].Children().ToList();
var zone = section.Key;
var site = rss[zone]["sites"];
foreach (var subsite in rss["zone1"]["sites"])
{
var subs = subsite.Parent.ToString();
// some other code
}
}
}
```
Looking for a result:
site1,
site2,
...
I can get the children as IList but looking for something similar to "section.Key" as noted above.
Thank you for your help.
I believe what you are looking for is to get the properties of the sites. Since accessing the rss["zone1"]["sites"] returns a JToken, you will need to convert that to JObject and then use Properties() method to get the data you need.
var sites = ((JObject)rss["zone1"]["sites"]).Properties();
Then you can simply iterate over the IEnumerable<Jproperty> to get the Name of the property or whatever else you need from under it.
To get the section.Key for the sites, you can use the following code.
foreach(var site in (JObject)rss["zone1"]["sites"]) {
Console.WriteLine(site.Key);
}
Output:
site1
site2
Your first call to JObject.Parse already does all the work of converting a string into a structured JSON object. The currently-accepted answer redoes some of this work by (1) turning a structured JSON object back into a string, and then (2) re-parsing it with JObject.Parse. There is a simpler way.
Instead, you can cast the value stored at rss["zone1"]["sites"] into a JObject. (The expression rss["zone1"]["sites"] has type JToken, which is a parent class of JObject, but in this case we happen to know that rss["zone1"]["sites"] is always JSON object, i.e. a collection of key-value pairs. Therefore, this cast is safe to perform.)
This is what the code might look like:
var sites = (JObject) rss["zone1"]["sites"];
foreach (var site in sites)
{
Console.WriteLine(site.Key);
}

JContainer, JObject, JToken and Linq confusion

I am having trouble understanding when to use JContainer, JObject, and JToken. I understand from the "standards" that JObject is composed of JProperties and that JToken is the base abstract class for all of the JToken types, but I don't understand JContainer.
I am using C# and I just bought LinqPad Pro 5.
I have a JSON data source in a file, so I'm deserializing that file's contents successfully using this statement:
string json;
using (StreamReader reader = new StreamReader(#"myjsonfile.json"))
{
json = reader.ReadToEnd();
}
At that point, I take the JSON string object and deserialize it to a JObject (and this might be my mistake--perhaps I need to make jsonWork a JToken or JContainer?):
JObject jsonWork = (JObject)JsonConvert.DeserializeObject(json);
In my JSON data (the string represented by JSON), I have three objects--the top-level object look similar to this:
{
"Object1" : { ... },
"Object2" : { ... },
"Object3" : { ... }
}
Each object is composed of all sorts of tokens (arrays, strings, other objects, etc.), so it is dynamic JSON. (I used ellipses as placeholders rather than muddying up this question wit lots of JSON data.)
I want to process "Object1", "Object2", and "Object3" separately using LINQ, however. So, ideally, I would like something like this:
// these lines DO NOT work
var jsonObject1 = jsonWork.Children()["Object1"]
var jsonObject2 = jsonWork.Children()["Object2"]
var jsonObject3 = jsonWork.Children()["Object3"]
But the above lines fail.
I used var above because I have no idea what object type I should be using: JContainer, JObject, or JToken! Just so you know what I want to do, once the above jsonObject# variables are properly assigned, I would like to use LINQ to query the JSON they contain. Here is a very simple example:
var query = from p in jsonObject1
where p.Name == "Name1"
select p
Of course, my LINQ ultimately will filter for JSON arrays, objects, strings, etc., in the jsonObject variable. I think once I get going, I can use LinqPad to help me filter the JSON using LINQ.
I discovered that if I use:
// this line WORKS
var jsonObject1 = ((JObject)jsonWork).["Object1"];
Then I get an JObject type in jsonObject1. Is this the correct approach?
It is unclear to me when/why one would use JContainer when it seems that JToken and JObject objects work with LINQ quite well. What is the purpose of JContainer?
You don't really need to worry about JContainer in most cases. It is there to help organize and structure LINQ-to-JSON into well-factored code.
The JToken hierarchy looks like this:
JToken - abstract base class
JContainer - abstract base class of JTokens that can contain other JTokens
JArray - represents a JSON array (contains an ordered list of JTokens)
JObject - represents a JSON object (contains a collection of JProperties)
JProperty - represents a JSON property (a name/JToken pair inside a JObject)
JValue - represents a primitive JSON value (string, number, boolean, null)
So you see, a JObject is a JContainer, which is a JToken.
Here's the basic rule of thumb:
If you know you have an object (denoted by curly braces { and } in JSON), use JObject
If you know you have an array or list (denoted by square brackets [ and ]), use JArray
If you know you have a primitive value, use JValue
If you don't know what kind of token you have, or want to be able to handle any of the above in a general way, use JToken. You can then check its Type property to determine what kind of token it is and cast it appropriately.
JContainer is a base class for JSON elements that have child items. JObject, JArray, JProperty and JConstructor all inherit from it.
For example, the following code:
(JObject)JsonConvert.DeserializeObject("[1, 2, 3]")
Would throw an InvalidCastException, but if you cast it to a JContainer, it would be fine.
Regarding your original question, if you know you have a JSON object at the top level, you can just use:
var jsonWork = JObject.Parse(json);
var jsonObject1 = jsonWork["Object1"];
Most examples have simple json and I've googled "C# Newtonsoft parse JSON" more than once.
Here's a bit of a json file I was just asked to parse for a csv. The company name value is nested within many arrays / objects so it is semi-complicated in that regard.
{
"page": {
"page": 1,
"pageSize": 250
},
"dataRows": [
{
"columnValues": {
"companyName": [
{
"name": "My Awesome Company",
}
]
}
}
]
}
var jsonFilePath = #"C:\data.json";
var jsonStr = File.ReadAllText(jsonFilePath);
// JObject implementation for getting dataRows JArray - in this case I find it simpler and more readable to use a dynamic cast (below)
//JObject jsonObj = JsonConvert.DeserializeObject<JObject>(jsonStr);
//var dataRows = (JArray)jsonObj["dataRows"];
var dataRows = ((dynamic)JsonConvert.DeserializeObject(jsonStr)).dataRows;
var csvLines = new List<string>();
for (var i = 0; i < dataRows.Count; i++)
{
var name = dataRows[i]["columnValues"]["companyName"][0]["name"].ToString();
// dynamic casting implemntation to get name - in this case, using JObject indexing (above) seems easier
//var name2 = ((dynamic)((dynamic)((dynamic)dataRows[i]).columnValues).companyName[0]).name.ToString();
csvLines.Add(name);
}
File.WriteAllLines($#"C:\data_{DateTime.Now.Ticks}.csv", csvLines);

Easily working on a json object

I'm deserializing (or parsing) a json string to a c# object (using Json.NET) and getting a JObject. I want to iterate all the properties with the key "bla", in the same way iterating all xml elements that named "bla" with XElement.Elements("bla").
If it's not possible, I would like to deserialize my json string into a c# object, and work dynamically and recursively on my deserialized json object (my json string can have lists / arrays that can have objects of 2 types.
In the end after editing my object (changing values and removing or adding properties) I need to serialize my object back to a json string.
Which is the best and easiest way to use json serializing and deserializing?
my Json looks like this:
{"Families":{"Family":[{"propA":"dhsj", "propB":"dhdisb"}, {"propA":"krbsbs", "propC":"ksndbd", "propD":"odndns", "Families":{"Family":[....]}}, {"propA":"dhsj", "propB":[{"propA":"dhsj", "propB":"dhdisb"}, {"propA":"krbsbs", "propC":"ksndbd", "propD":"odndns", "Families":{"Family":[....]}}, {"propA":"dhsj", "propB":"fghfgh"}]}]}
in conclusion, the json value is a json object that it's value is a list/array, the list/array can contain 2 "types" of objects, and one of these types also has a property which it's value is a json object that it's value is a list/array, and it goes like this recursively. sometimes the value of one of the props of the type that doesn't have a property which it's value is a json object that it's value is a list/array, can be a list/array itself, that can contain only 1 type of the two mentioned.
If you don't need a strongly-typed object, you can deserialize to a dictionary:
Dictionary<string, object> myObject = JsonConvert.DeserializeObject<Dictionary<string, object>>(jsonString);
And then just use it as a dictionary:
myObject["Property"] = value;
Or
foreach(var propertyKey in myObject.Keys)
{
// do something with each property
Console.WriteLine($"{propertyKey} = {myObject[propertyKey]}");
}
Here's a fiddle
You can serialize it back after you are done
My json looks more like this:
{"Familys":{"Family":[{"propA":"dhsj", "propB":"dhdisb"}, {"propA":"krbsbs", "propC":"ksndbd", "propD":"odndns", "Families":{"Family":[....]}}]}
For JSON like this:
var json = #"{
""Families"":{
""Family"":[
{
""propA"":""Top""
},
{
""propA"":""Top.Lower"",
""Families"":{
""Family"":[
{
""propB"":""propB value""
},
{
""propA"":""Top.Lower.EvenLower"",
""Families"":{
""Family"":[
{
""propA"":""Top.Lower.EvenLower.EvenLower""
}
]
}
}
]
}
}
]
}
}";
Do something like this:
//calling code makes use of "dynamic" to make things clean and readable.
dynamic parsedJson = JsonConvert.DeserializeObject(json);
var allPropAValues = GetPropAValues(parsedJson);
//**** NOTE: this has our extra property ****
var jsonWithExtraStuffProperty = JsonConvert.SerializeObject(parsedJson);
//recursive function that reads AND writes properties
public static List<string> GetPropAValues(dynamic obj)
{
var propAValues = new List<string>();
//**** NOTE: the use of an added property ****
obj.ExtraStuff = new Random().Next();
//if we have a propA value, get it.
if (obj.propA != null)
propAValues.Add(obj.propA.Value);
//iterate through families if there are any. your JSON had Families.Family.
if (obj.Families != null)
foreach (dynamic family in obj.Families.Family)
propAValues.AddRange(GetPropAValues(family));
return propAValues;
}

How to create a json string where a property contains a dot (period)?

I'm trying to send an HttpRequest that takes a JSON object like this:
{
"some.setting.withperiods":"myvalue"
}
I've been creating anonymous objects for my other requests, but I can't do that with this one since the name contains a dot.
I know I can create a class and specify the [DataMember(Name="some.setting.withperiods")] attribute, but there must be a more lightweight solution.
There is no "easy" way to achieve this because the . in C# is reserved.
However, you could achieve something pretty close by using a dictionary and collection initializer. It's still somewhat isolated, and doesn't require you to create a custom class.
var obj = new Dictionary<string, object>
{
{ "some.setting.withperiods", "myvalue" }
};
var json = JsonConvert.SerializeObject(obj);
//{"some.setting.withperiods":"myvalue"}
You can use "JsonProperty" attribute for the same For example
[JsonProperty(".Name")]
public string Name { get; set; }
On top of this I want to add how to retrieve the data from the json where it has name property starting with special character as in Web API 2.0 token has ".issued".
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
var jsonRespons="json response from the web api";
var issue= JObject.Parse(jsonResponse).GetValue(".issued");
if you do it from in javascript, you can easily go back and forth, as shown with:
var obj = {
"some.setting.withdots":"myvalue"
};
var json = JSON.stringify(obj);
console.log(json);
var str = JSON.parse(json);
console.log(str);
have you tried putting it into a serialized string and sending that, then deserializing on the client-side?
you could do something like
var myAnnon = new
{
WithPeriod = "value"
};
var j = JsonConvert.SerializeObject(myAnnon);
j = j.Replace("WithPeriod", "some.setting.withdots");
You can use a JObject (part of Json.Net's LINQ-to-JSON API) to create the JSON in question:
string json = new JObject(new JProperty("some.setting.withperiods", "myvalue")).ToString();
Fiddle: https://dotnetfiddle.net/bhgTta
You could try prefixing your member names with a # to allow use of literals, but the way to do it is using [DataMember] as you have already mentioned in your question.

how to serialize a json string to a form post data

I need to POST a JSON string to a page.
The page is external and out of my control, and it expects the post data to be in the web-form post format (key1=value1&key2=value2)
How can I convert the JSON string to this format?
This can be done by first deserializing your JSON to a Dictionary<string, string>, then iterating through the key-value pairs in the dictionary and building up a querystring from that.
However, keep in mind that querystring format (application/x-www-form-urlencoded) is not a hierarchical format, while JSON is. So your JSON object can only be a simple object with key-value pairs (no arrays or nested objects). If your JSON is more complicated than that, you will have to do some more work to flatten it before you can convert it to a querystring.
Demo:
class Program
{
static void Main(string[] args)
{
string json = #"
{
""key1"" : ""value1"",
""key2"" : ""value2"",
""int"" : 5,
""bool"" : true,
""decimal"" : 3.14,
""punct"" : ""x+y=z""
}";
var dict = JsonConvert.DeserializeObject<Dictionary<string, string>>(json);
StringBuilder sb = new StringBuilder();
foreach (KeyValuePair<string, string> kvp in dict)
{
if (!string.IsNullOrEmpty(kvp.Key) && !string.IsNullOrEmpty(kvp.Value))
{
if (sb.Length > 0) sb.Append('&');
sb.Append(HttpUtility.UrlEncode(kvp.Key));
sb.Append('=');
sb.Append(HttpUtility.UrlEncode(kvp.Value));
}
}
var postDataString = sb.ToString();
Console.WriteLine(postDataString);
}
}
Output:
key1=value1&key2=value2&int=5&bool=True&decimal=3.14&punct=x%2by%3dz
As was mentioned in the comments, you can use the FormUrlEncodedContent class to do the same thing. Replace the StringBuilder and foreach loop in the code above with the following (but note this approach requires async/await):
var formUrlEncodedContent = new FormUrlEncodedContent(dict);
var postDataString = await formUrlEncodedContent.ReadAsStringAsync();
You don't post JSON like that. You set the Content-Type header to "application/json" and then you simply fill the content body with the JSON as-is.
There is no built in support in C# or JSON.NET to serialize JSON into form post data, but you can probably use LINQ to JSON to write a translater yourself relatively easy, assuming the JSON format is simple enough.
Is the Json being passed in always the same? Your best bet is to deserialize the Json to a C# class then create your post data from that.

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