Develop Reference

How to generate a JSON class with dynamic name

I don't know if there is an existing name for that case, but I'm trying to retrieve data from NASA API (https://api.nasa.gov/) and I have a simple challenge to catch a list of objects near earth. Here is the JSON response I have from the GET request I do to "https://api.nasa.gov/neo/rest/v1/feed?...."
{
"links": {
"next": "http://www.neowsapp.com/rest/v1/feed?start_date=2021-07-04&end_date=2021-07-04&detailed=false&api_key=NjgpxgSbYHXyFSBI3HaOhRowtjMZgAKv2t4DMRym",
"prev": "http://www.neowsapp.com/rest/v1/feed?start_date=2021-07-02&end_date=2021-07-02&detailed=false&api_key=NjgpxgSbYHXyFSBI3HaOhRowtjMZgAKv2t4DMRym",
"self": "http://www.neowsapp.com/rest/v1/feed?start_date=2021-07-03&end_date=2021-07-03&detailed=false&api_key=NjgpxgSbYHXyFSBI3HaOhRowtjMZgAKv2t4DMRym"
},
"element_count": 6,
"near_earth_objects": {
"2021-07-03": [
{
"links": {
"self": "http://www.neowsapp.com/rest/v1/neo/3701710?api_key=NjgpxgSbYHXyFSBI3HaOhRowtjMZgAKv2t4DMRym"
},
"id": "3701710",
"neo_reference_id": "3701710",
"name": "(2014 WF497)",
"nasa_jpl_url": "http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3701710",
"absolute_magnitude_h": 20.23,
"estimated_diameter": {
"kilometers": {
}
And that's the way it is built in Visual Studio (using the Special Paste option for JSON)
public class NearEarthObject
{
public Links links { get; set; }
public int element_count { get; set; }
public Near_Earth_Objects near_earth_objects { get; set; }
}
public class Links
{
public string next { get; set; }
public string prev { get; set; }
public string self { get; set; }
}
public class Near_Earth_Objects
{
public _20210703[] _20210703 { get; set; }
}
public class _20210703
{
public Links1 links { get; set; }
public string id { get; set; }
public string neo_reference_id { get; set; }
public string name { get; set; }
public string nasa_jpl_url { get; set; }
public float absolute_magnitude_h { get; set; }
public Estimated_Diameter estimated_diameter { get; set; }
public bool is_potentially_hazardous_asteroid { get; set; }
public Close_Approach_Data[] close_approach_data { get; set; }
public bool is_sentry_object { get; set; }
}
The question is, inside of the element "near_earth_objects", there is an element called "2021-07-03" (the date of the data I requested), the problem is that I am trying to include it into a DataGridView made in .NET C# (Windows Forms, but that doesn't matters here, I think) and the user wants to get the information by date. So, "2021-07-03" is a valid member just for one day, and the user should be able to get data from multiple days.
So, is there a way in C# to get all child objects inside of near_earth_objects without knowing their names since there will be the option to search for asteroids from date X to Y in my application?

Using System.Text.Json
The API response will map to the following classes
public class Neo
{
public Links Links { get; set; }
public int ElementCount { get; set; }
public Dictionary<string, List<NearEarthObject>> NearEarthObjects { get; set; }
}
public class Links
{
public string Next { get; set; }
public string Prev { get; set; }
public string Self { get; set; }
}
public class NearEarthObject
{
public Links Links { get; set; }
public string Id { get; set; }
public string Name { get; set; }
// Other properties
}
The NearEarthObjects is simply a Dictionary, where the key is the formatted date and value is a List containing NearEarthObject
The PropertyNamingPolicy will allow us to support the API's underscore property naming convention.
public class UnderscoreNamingPolicy : JsonNamingPolicy
{
public override string ConvertName(string name)
{
return name.Underscore();
}
}
Example usage
// using using System.Text.Json;
var response = await new HttpClient().GetStringAsync(url);
var neo = JsonSerializer.Deserialize<Neo>(response, new JsonSerializerOptions
{
PropertyNamingPolicy = new UnderscoreNamingPolicy()
});
foreach(var neos in neo.NearEarthObjects)
{
Console.WriteLine(neos.Key);
}

use System.Text.Json, JsonNamingPolicy
demo code
public class DynamicNamePolicy : JsonNamingPolicy
{
public override string ConvertName(string name)
{
var today = DateTime.Today.ToString("yyyy-MM-dd");
if (name.Equals("DateData")) //model property name
return today; //convert to json string property name
return name;
}
}
//data deserialize
string data = ""; //json string
var obj = JsonSerializer.Deserialize<NearEarthObject>(data, new JsonSerializerOptions
{
PropertyNamingPolicy = new DynamicNamePolicy(),
});

JSON with array structure [duplicate]

This question already has answers here:
How can I deserialize JSON with C#?
(19 answers)
How to auto-generate a C# class file from a JSON string [closed]
(3 answers)
Closed 2 years ago.
I just wanna ask if how to implement in c# a json data with array structure. This is the sample data below:
{
"contact":
{
"contact_type_ids": ["CUSTOMER"],
"name":"JSON Sample ResellerAVP",
"main_address":
{
"address_type_id":"ACCOUNTS",
"address_line_1":"Ayala Hills",
"city":"Muntinlupa",
"region":"NCR",
"postal_code":"1770",
"country_group_id":"ALL"
}
}
}

JSON overview:
{ } - Object
[ ] - Array
"a": something - Property
A property can have an object, array, or value type as its value. For example:
{
"a": true,
"b": "hello",
"c": 5.2,
"d": 1,
"e": { "eChildProperty": "test" },
"f": [ "a", "b", "c" ]
}
Let's start transcribing this JSON into classes!
{
"contact":
{
"contact_type_ids": ["CUSTOMER"],
"name":"JSON Sample ResellerAVP",
"main_address":
{
"address_type_id":"ACCOUNTS",
"address_line_1":"Ayala Hills",
"city":"Muntinlupa",
"region":"NCR",
"postal_code":"1770",
"country_group_id":"ALL"
}
}
}
OK, so we have a root object with a property "contact", which is also an object. Let's represent both of those:
public class RootObject
{
public Contact Contact { get; set; }
}
public class Contact
{
}
Now we need to add Contact's properties. It has 3: contact_type_ids is an array of strings, name is a string, and main address is a complex object. Let's represent those:
public class Contact
{
[JsonProperty("contact_type_ids")]
public IList<string> ContactTypeIds { get; set; } // I'm using an IList, but any collection type or interface should work
public string Name { get; set; }
[JsonProperty("main_address")]
public Address MainAddress { get; set; }
}
public class Address
{
}
Finally we need to work on the Address object:
public class Address
{
[JsonProperty("address_type_id")]
public string AddressTypeId { get; set; }
[JsonProperty("address_line_1")]
public string AddressLine1 { get; set; }
public string City { get; set; }
public string Region { get; set; }
[JsonProperty("postal_code")]
public string PostalCode { get; set; }
[JsonProperty("country_group_id")]
public string CountryGroupId { get; set; }
}
Putting this all together we get:
public class RootObject
{
public Contact Contact { get; set; }
}
public class Contact
{
[JsonProperty("contact_type_ids")]
public IList<string> ContactTypeIds { get; set; } // I'm using an IList, but any collection type or interface should work
public string Name { get; set; }
[JsonProperty("main_address")]
public Address MainAddress { get; set; }
}
public class Address
{
[JsonProperty("address_type_id")]
public string AddressTypeId { get; set; }
[JsonProperty("address_line_1")]
public string AddressLine1 { get; set; }
public string City { get; set; }
public string Region { get; set; }
[JsonProperty("postal_code")]
public string PostalCode { get; set; }
[JsonProperty("country_group_id")]
public string CountryGroupId { get; set; }
}
And we can use it like so:
RootObject deserialized = JsonConvert.DeserializeObject<RootObject>(jsonString);
Try it online
JSON isn't complicated by any stretch of the imagination. It's really simple to understand and manually convert into classes just by looking at the data you have.

How to set up class for json?

I am working with opentdb.com api and have no idea how to access data in this json:
{
"response_code":0,
"results": [
{
"category":"Animals",
"type":"multiple",
"difficulty":"easy",
"question":"What is the scientific name for modern day humans?",
"correct_answer":"Homo Sapiens",
"incorrect_answers":[
"Homo Ergaster",
"Homo Erectus",
"Homo Neanderthalensis"
]
},
{
"category":"Entertainment: Cartoon & Animations",
"type":"multiple",
"difficulty":"easy",
"question":"Who voices for Ruby in the animated series RWBY?",
"correct_answer":"Lindsay Jones",
"incorrect_answers":[
"Tara Strong",
"Jessica Nigri",
"Hayden Panettiere"
]
}
]
}
I am using Newtonsoft.Json and i tried this with only 1 Question but im geting an error that says that key value is wrong..
class Trivia
{
public Trivia(string json)
{
JObject jObject = JObject.Parse(json);
JToken jresults = jObject["results"];
category = (string)jresults["category"];
type = (string)jresults["type"];
difficulty = (string)jresults["difficulty"];
question = (string)jresults["question"];
correct_answer = (string)jresults["correct_answer"];
incorrect_answers = jresults["incorrect_answers"].ToArray();
}
public string category { get; set; }
public string type { get; set; }
public string difficulty { get; set; }
public string question { get; set; }
public string correct_answer { get; set; }
public Array incorrect_answers { get; set; }
}

Copy from json text and in new class in visual studio Edit-->Paste Special-->Paste JSON As Classes
public class Rootobject
{
public int response_code { get; set; }
public Result[] results { get; set; }
}
public class Result
{
public string category { get; set; }
public string type { get; set; }
public string difficulty { get; set; }
public string question { get; set; }
public string correct_answer { get; set; }
public string[] incorrect_answers { get; set; }
}
using namespace
using Newtonsoft.Json;
response is value get from your service
var outdeserialized = JsonConvert.DeserializeObject<Rootobject>(response);

JSon.NET deserialising subitems

For deserialisation I usually use an object with the same property names as found in the JSon and JsonConvert.DeserializeObject<Des>(jsonstring).
But now I came across this:
{
"id": 0815,
"name": "whatever"
"addedInfo": {
"thisisinteresting": 4711,
"id_str": "2336"
}
}
How can I tell JSon.Net to pull the 'thisisinteresting' part of the sub category into a class like:
class Des
{
int id;
string name;
int thisisinteresting;
}

The trivial way would be to actually model your class to the JSON structure:
public class AddedInfo
{
public int thisisinteresting { get; set; }
public string id_str { get; set; }
}
public class RootObject
{
public int id { get; set; }
public string name { get; set; }
public AddedInfo addedInfo { get; set; }
}
Then add a property to the RootObject to emit the property:
public class RootObject
{
public int id { get; set; }
public string name { get; set; }
public AddedInfo addedInfo { get; set; }
[JsonIgnore]
public int thisisinteresting { get { return addedInfo.thisisinteresting; } }
}
There are alternatives like creating a custom serializer or using JObject and deserialize the structure yourself, but I won't go into that. If you need to parse the JSON anyway, the price to deserialize it entirely is small.

WCF writing Nested Json Webservice

I have to write a WCF webservice in dot net in nested Json structured below. I know how to write simple json but not sure to make it nested for `results
{
"version": 2,
"results": [{
"company": "ABC Company Inc.",
"city": "Sacramento",
"state": "CA"
}
]
}
What I am doing is :
file1.cs
namespace Test
{
public class file1
{
public class child
{
[DataMember]
public string version { get; set; }
}
public class parent
{
[DataMember]
public string company { get; set; }
[DataMember]
public string city { get; set; }
}
}
}
In file2.svc.cs
public List<file1> method()
{
List<file1.child> result = new List<file1.child>();
List<file1.parent> result1 = new List<file1.parent>();
List<file1> final = new List<file1>();
foreach (DataRow catt1 in dtcategory.Rows)
{
result.Add(new file1.child()
{
version= catt1["version"].ToString(),
});
result1.Add(new file1.parent() {
company= catt1["company"].ToString(),
city= catt1["city"].ToString(),
});
final.Add(new file1()
{
});
}
return Add;
}
Please let me where I am going wrong

Class Structure:
public class class1
{
[DataMember]
public string version {get;set;}
[DataMember]
public List<class2> results {get;set;}
}
public class class2
{
[DataMember]
public string company {get;set;}
[DataMember]
public string city{get;set;}
[DataMember]
public string state {get;set;}
}

Your question is sort of unclear. However, if you are asking "how can I design my classes file1.child and file1.parent so that, when serialized by DataContractJsonSerializer or Json.NET, they produce the JSON shown", then you can do:
public class file1
{
[DataContract]
public class child
{
[DataMember(Name="version")]
public string Version { get; set; }
[DataMember(Name="results")]
public List<parent> Results { get; set; }
}
[DataContract]
public class parent
{
[DataMember(Name="company")]
public string Company { get; set; }
[DataMember(Name="city")]
public string City { get; set; }
[DataMember(Name="state")]
public string State { get; set; }
}
}
Note that, given your class names, parent is contained inside child, which is counterintuitive. You might want to change those names.