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C# API requests which return a class

Hey all (newbie here) I am developing A Xamarin forms application In which I am already making API requests (Code is Down Below), However, the response I am getting back at the moment looks like this:
{
"result": "success",
"documentation": "https://www.exchangerate-api.com/docs",
"terms_of_use": "https://www.exchangerate-api.com/terms",
"time_last_update_unix": 1673308801,
"time_last_update_utc": "Tue, 10 Jan 2023 00:00:01 +0000",
"time_next_update_unix": 1673395201,
"time_next_update_utc": "Wed, 11 Jan 2023 00:00:01 +0000",
"base_code": "EUR",
"target_code": "GBP",
"conversion_rate": 0.8803
}
I am Only using the conversion rate variable however in the next API I am hoping to use all this variables are stored in parameters (Class I guess?) called Data, so currently, the class I am using to store the variable which is grabbed from this API response looks like this:
public double conversion_rate { get; set; }
So how would I adapt this code to interpret that data, the response is below (I want the data labeled "actual" in the "intensity" section TIA):
"data": [
{
"from": "2023-01-10T19:30Z",
"to": "2023-01-10T20:00Z",
"intensity": {
"forecast": 70,
"actual": 79,
"index": "low"
}
}
]
Ive attempted to find a solution on my own for a while, looked all around and still nothing to see :)

I would create two DTO (data transfer object) classes which contain the properties you're interested in. Once you make the API request, you can map or parse the relevant fields to another object or type.
FYI - you should rename conversion_rate to ConversionRate, which is the standard for property names in C# and then add [JsonPropertyName("conversion_rate")] above the property.

First, you can write the c# class entity based on the json file. Here is the demo and you can refer to.
public class Root
{
public string result { get; set; }
public string documentation { get; set; }
public string terms_of_use { get; set; }
public int time_last_update_unix { get; set; }
public string time_last_update_utc { get; set; }
public int time_next_update_unix { get; set; }
public string time_next_update_utc { get; set; }
public string base_code { get; set; }
public string target_code { get; set; }
public double conversion_rate { get; set; }
}
Then, you can write the method to deserialize the json file.
using System.Text.Json;
var options = new JsonSerializerOptions()
{
PropertyNamingPolicy = JsonNamingPolicy.CamelCase
};
var codeRoot = JsonSerializer.Deserialize<Root>(Json, options);

Q: How to form LINQ query to access nested attributes within class to display on Blazor WASM application

My apologies for the vast amount of code, but it is necessary for the context of the problem. I am faced with an interesting dilemma that I have not been able to solve. I am trying to access information from model called Repository. Repository contains nested classes and lists, and looks like this:
{
public User User { get; set; }
}
public class User
{
public PinnedItems PinnedItems { get; set; }
}
public class PinnedItems
{
public List<Nodes> Nodes { get; set; }
}
public class Nodes
{
public string Name { get; set; }
public string Description { get; set; }
public string Url { get; set; }
public RepositoryTopics RepositoryTopics { get; set; }
}
public class RepositoryTopics
{
public List<TopicNodes> Nodes { get; set; }
}
public class TopicNodes
{
public Topic Topic { get; set; }
}
public class Topic
{
public string Name { get; set; }
}
I have the following method within a web api controller. It is responsible for grabbing my github repositories using graphql. This method looks like this:
{
var request = new GraphQLHttpRequest
{
Query = #"query($username: String!){
user(login: $username) {
pinnedItems(first: 6, types: REPOSITORY) {
nodes {
... on Repository {
name
description
url
repositoryTopics(first:6){
nodes{
topic{
name
}
}
}
}
}
}
}
}
",
Variables = new
{
username = _configuration.GetSection("GithubUserName").Value
}
};
var graphQlResponse = await CreateClient().SendQueryAsync<Repository>(request);
var repo = new Repository
{
User = graphQlResponse.Data.User
};
return Ok(repo);
}
repo is of type Repository.
This is an example piece of JSON that comes back from testing the controller in swagger.
"pinnedItems": {
"nodes": [
{
"name": "personal-website",
"description": "My personal website",
"url": "https://github.com/personal-website",
"repositoryTopics": {
"nodes": [
{
"topic": {
"name": "blazor-webassembly"
}
},
{
"topic": {
"name": "web-api"
}
},
{
"topic": {
"name": "contentful-api"
}
},
{
"topic": {
"name": "contentful"
}
}
]
}
}
I am accessing the code in my blazor component with the following:
Repository SoftwareRepos = new Repository();
protected async override Task OnInitializedAsync()
{
SoftwareRepos = await graphQLquery.GetRepositories();
}
}
And some example code such as this gets me the list of projects as a name.
#foreach(var name in SoftwareRepos.User.PinnedItems.Nodes.Select(x => x.Name).ToArray())
{
#name
}
PRINTS OUT: name, name, name, name
Ideally I would want something that looks like this:
Project One, Description, URL, html, css, react, javascript (a list of tags)
I am having trouble trying to construct LINQ queries to access this nested information (particularly repositoryTopic -> TopicNodes -> Nodes -> Topics -> Name.
I am seeking advice on how to approach this situation, or maybe some alternative solutions to what I am doing as I suspect I am a little out of my depth here. I am using graphql.client to send and retrieve information from github.

first thing to do is to deserialize that JSON into a class structure that it represents.
public class GitResponse{
public Node[] PinnedItems {get;set;}
}
public class Node{
public string Name {get;set};
public string Description {get;set;}
....
}
etc. Once this is done the rest is easy , you just walk that tree
deserialize with
System.Text.Json.Serailizer.Deserialize<GitResponse>(json);

C# - extracting values from JSON object with "System" in property names

At the beginning I want to say that 'm not a C# developer by any means, however at my work I've received a task where I have to write simple web service in .net.
The task is not very complicated however I've encountered the problem that JSON payload which is sent to our web service has "System" in property names:
"resource": {
"fields": {
"System.AreaPath": "someData",
"System.TeamProject": "someData",
"System.IterationPath": "someData"
}
}
I'm trying to get those values by using:
public class Resource
{
public Fields System.AreaPath { get; set; }
}
However I'm getting an error ("System" is a namespace but used like a type.)
Are there any best practices on how to perform such task ?
Thank you.

One easy option it to specify the JSON property in an attribute. If you're using Json.NET you can use [JsonProperty] for this. Complete example:
using System;
using System.IO;
using Newtonsoft.Json;
public class Fields
{
[JsonProperty("System.AreaPath")]
public string AreaPath { get; set; }
[JsonProperty("System.TeamProject")]
public string TeamProject { get; set; }
[JsonProperty("System.IterationPath")]
public string IterationPath { get; set; }
}
public class Resource
{
public Fields Fields { get; set; }
}
class Program
{
static void Main()
{
string json = File.ReadAllText("test.json");
var resource = JsonConvert.DeserializeObject<Resource>(json);
Console.WriteLine(resource.Fields.TeamProject);
}
}
JSON (removed the "resource" part to make it a complete JSON document; I assume you know how to handle this if necessary):
{
"fields": {
"System.AreaPath": "someData",
"System.TeamProject": "team project",
"System.IterationPath": "someData"
}
}
Output: team project

Deserialize JSON array of values in C#

I've got some difficulties with this json script:
{
"insured_agent_flag": "a",
"id": "1",
"agent": {
"fullName": "John Travolta",
"mobileNumberPdf": "+987654321",
"mobileNumber": "",
"identityCard": {
"identityCardExpirationDate": null
},
"secondIdentityCard": {
"identityCardExpirationDate": null
},
"notes": {},
"sign": "ADVANCED"
},
"basicData": {
"personType": "PERSON",
"agreeWithCompleteAnalysis": false,
"investmentInterest": false
},
"nonOfferedProducts": [
"PROD_A",
"PROD_B",
"PROD_C"
]
}
I would like to get some parameters from this script and put it into sql server table.
In order to do that, I used and transformed a C# script shared by https://mycontraption.com:
using System;
using System.Data;
using System.Collections.Generic;
using System.Linq;
using Microsoft.SqlServer.Dts.Pipeline.Wrapper;
using Microsoft.SqlServer.Dts.Runtime.Wrapper;
using System.Web.Script.Serialization;
using Microsoft.SqlServer.Dts.Pipeline;
namespace SC_c7e2d8c3918d46a5a07a1b438ddc7642
{
public class BasicData
{
public string agreeWithCompleteAnalysis { get; set; }
public string inOtherSystem { get; set; }
public string investmentInterest { get; set; }
}
public class ParentObject
{
public BasicData BasicData { get; set; }
public int id { get; set; }
public string insured_agent_flag { get; set; }
public IEnumerable<string> NonOfferedProducts { get; set; }
}
[Microsoft.SqlServer.Dts.Pipeline.SSISScriptComponentEntryPointAttribute]
public class ScriptMain : UserComponent
{
public override void Input0_ProcessInputRow(Input0Buffer Row)
{
JavaScriptSerializer js = new JavaScriptSerializer();
// Give the input column a variable to make it easier to reference.
BlobColumn combinedColumn = Row.parameterscon;
// Convert from blob to string
string reviewConverted = System.Text.Encoding.ASCII.GetString(combinedColumn.GetBlobData(0, Convert.ToInt32(combinedColumn.Length)));
// Deserialize the string
ParentObject obj = js.Deserialize<ParentObject>(reviewConverted);
var rows = obj.NonOfferedProducts.ToList();
Row.agreeWithCompleteAnalysis = obj.BasicData.agreeWithCompleteAnalysis;
Row.inOtherSystem = obj.BasicData.inOtherSystem;
Row.investmentInterest = obj.BasicData.investmentInterest;
Row.projectionid = obj.id;
Row.insuredagentflag = obj.insured_agent_flag;
//Row.nonOfferedProducts =
}
}
}
For 'standard' objects it works fine, but there is a problem with array "nonOfferedProducts". After compiling I get an error:
„object reference not set to an instance of an object”.
Here are my questions:
1. How should I handle 'nonOfferedProducts' array in C# script?
2. Why do I get foregoing error?
3. Unfortunately there exists a possibility, that json scripts would have some errors, like missing braces. How should I handle that?
Thank you!
Thanks a lot for your answers. According to your comments I'll try to give you more explanations:
1. The json script I have added in this post - it's only small part of whole script. In complete script there is a lot of different parameters. What is more, my C# code should scan about 40.000 json scripts (stored in sql server table in one column). These scripts has got similiar structure - but not the same.
So I thought about C# resolution, that will be searching for the parameters that I need. For json scripts without these parameters the c# code will put nulls to the right output columns.
Here are my output columns:
-agreeWithCompleteAnalysis
-inOtherSystem
-investmentInterest
-projectionId
-insuredAgentFflag
-nonOfferedProducts
I understood, that structure of my classes were wrong - I'll improve that.
But I've got one doubt - is it possible to prepare c# code structure, that will handle only these parameters I need?
And finally, I would like to put the results into my database.
For example if nonOfferedProducts property will have 3 values (not always!), I'd like to send to my database table 3 records (3 different values for nonOfferedProducts column and 3 the same values for the rest columns -agreeWithCompleteAnalysis, inOtherSystem etc).
I hope that will be clear now.
Thanks a lot for your help!
J

Use https://quicktype.io and paste json, it will generate c# model and serializer code.

As I said in my comment, your c# model doesn't match the JSON object.
If the model was made up of various nested objects to better reflect the actual JSON then you'll have more luck:
public class IdentityCard
{
public DateTime? IdentityCardExpirationDate { get; set; }
}
public class Notes
{
//No idea what should be in here...
}
public class BasicData
{
public string PersonType { get; set; }
public bool AgreeWithCompleteAnalysis { get; set; }
public bool InvestmentInterest { get; set; }
}
public class Agent
{
public string FullName { get; set; }
public string MobileNumberPdf { get; set; }
public string MobileNumber { get; set; }
public IdentityCard IdentityCard { get; set; }
public IdentityCard SecondIdentityCard { get; set; }
public Notes Notes { get; set; }
public string Sign { get; set; }
}
//Note: THIS is the actual class that matches the JSON sample given.
public class ParentObject
{
public string insured_agent_flag { get; set; }
public int Id { get; set; }
public Agent Agent { get; set; }
public BasicData BasicData { get; set; }
public IEnumerable<string> NonOfferedProducts { get; set; }
}
Once the model is correct, then Deserialization works fine for me with the given example (I did this in a unit test, but assuming your string matches your example this should be fine)
//get json
string json = #"
{
""insured_agent_flag"": ""a"",
""id"": ""1"",
""agent"": {
""fullName"": ""John Travolta"",
""mobileNumberPdf"": ""+987654321"",
""mobileNumber"": """",
""identityCard"": {
""identityCardExpirationDate"": null
},
""secondIdentityCard"": {
""identityCardExpirationDate"": null
},
""notes"": {},
""sign"": ""ADVANCED""
},
""basicData"": {
""personType"": ""PERSON"",
""agreeWithCompleteAnalysis"": false,
""investmentInterest"": false
},
""nonOfferedProducts"": [
""PROD_A"",
""PROD_B"",
""PROD_C""
]
}";
var js = new JavaScriptSerializer();
ParentObject obj = js.Deserialize<ParentObject>(json);
//do things...
var rows = obj.NonOfferedProducts.ToList();
Assert.AreEqual(3, rows.Count);
Assert.AreEqual("PROD_A", rows.First());
The asserts pass - This code happily gets the list of strings in the NonOfferedProducts property with the given example.
Obviously if you cannot rely on the consistency of the JSON (either structure or how well-formed it is) then you'll have problems, but that's a different issue.

To answer your question no 2) you are getting the object reference error because the BasicDataClass.nonOfferedProducts is null and you are trying iterate over it , this may be a reason that you are sending the wrong json which JavaScriptSerializer is not able to deserilize.
your 3rd question you can always validate your json with json validators which are there online like https://jsonformatter.org/

How to Deserialize JSON data? C#

Im getting a Json Data from an API and i have been trying to deserialize.
Json data:
{
   "items": [
      {
         "id": "1",
         "name": "samplename",
         "AddressList1": {
            "City": "Hyd",
            "State": "TN",
            "Country": "IN"
         },
         "Age": "10"
      },
      {
         "id": "2",
         "name": "samplename2",
         "AddressList1": {
            "City": "Hydd",
            "State": "TN",
            "Country": "IN"
         },
         "Age": "10"
      }
   ],
   "paging": {
      "cursors": {}
   }
}
Entities:
public class AddressList1
{
public string City { get; set; }
public string State { get; set; }
public string Country { get; set; }
}
public class Item
{
public string id { get; set; }
public string name { get; set; }
public AddressList1 addressList1 { get; set; }
public string Age { get; set; }
}
public class Cursors
{
}
public class Paging
{
public Cursors cursors { get; set; }
}
public class Users
{
public List<Item> items { get; set; }
public Paging paging { get; set; }
}
C# code:
JsonConvert.DeserializeObject<List<Users>>(content);
Error Message:
Cannot deserialize the current JSON object (e.g. {"name":"value"})
into type 'System.Collections.Generic.List`1[Entities.Users]'
because the type requires a JSON array (e.g. [1,2,3]) to deserialize
correctly.
where am i doing wrong?

The following is a JSON-object; in your case a User
{ ... }
The following is a JSON-array; in your case an array of User
[ { ... }, { ... } ]
Thus if you want to deserialize the JSON you got into an array of Users this is not possible because you have no array in JSON.
Therefore the right code to deserialize is:
JsonConvert.DeserializeObject<Users>(content);
Furthermore your mapping is erroneous because in JSON there is a property AddressList1 and in the class it is called addressList1

Given your JSON, you would need a POCO object that contains a items member and a paging member.
JsonConvert.DeserializeObject<Users>(content);
should work.

Your Json string is good formatted and the entities are according to Json2Csharp good too.
but your problem is with the instruction JsonConvert.DeserializeObject<List<Users>>(content);
all that json that you have is only ONE User, and you are trying to get a list of them, there is the issue,
you can try instead with:
JsonConvert.DeserializeObject<Users>(content);

Try Below Code
JsonConvert.DeserializeObject<Users>(content);

Your entities(models) look just fine. If you are using, or were to use ASP.NET Web API 2, and your client is using the http verb post for example, this setup would work as Web API takes care of the object deserialization:
public HttpStatusCode Post(Item item)
{
Debug.Write(item.toString());
return HttpStatusCode.OK;
}
If you insist in deserializing manually then use the JavaScriptSerializer library which allows you to do things like:
Item item = new JavaScriptSerializer().Deserialize<Item>(content);
Notice that .Deserialize<T>() takes a generic which in your case it Item.
Hope that helps.