Develop Reference

class property manipulation when parsing json data in c#

I am practicing with web api. My goal is to create a Get endpoint, which receive data from an external api, then return a different result. external api link: https://www.themealdb.com/api/json/v1/1/search.php?f=a, The external api data looks like:
{
"meals": [
{
"idMeal": "52768",
"strMeal": "Apple Frangipan Tart",
"strDrinkAlternate": null,
"strCategory": "Dessert",
.....
},
{
"idMeal": "52893",
"strMeal": "Apple & Blackberry Crumble",
....
}
]
}
I want my endpoint provide a different result like the following:
[
{
"idMeal": "52768",
"strMeal": "Apple Frangipan Tart",
"ingredients": ["Apple", "sugar"...]
},
{
"idMeal": "52893",
"strMeal": "Apple & Blackberry Crumble",
"ingredients": ["Apple", "sugar"...]
}
]
The following code is what I attempted so far, It's working, but the moment I changed property ingredient1 from public to private, that ingredient in list will become null, also, there are so many ingredients, some of them are null by default, I don't want to add them if they are null, how can I fix these two issues? Thanks a lot
using System.Text.Json;
using System.Text.Json.Serialization;
using Microsoft.AspNetCore.Mvc;
using RestSharp;
namespace testAPI.Controllers;
public class Content
{
[JsonPropertyName("meals")]
public List<Meal> Meals { get; set; }
}
public class Meal
{
[JsonPropertyName("idMeal")]
public string MealId { get; set; }
[JsonPropertyName("strMeal")]
public string Name { get; set; }
[JsonPropertyName("strIngredient1")]
public string Ingredient1 { get; set; }
[JsonPropertyName("strIngredient2")]
public string Ingredient2 { get; set; }
[JsonPropertyName("strIngredient20")]
public string Ingredient20 { get; set; }
public List<string> Ingredients
{
get { return new List<string>(){Ingredient1, Ingredient2, Ingredient20};}
}
}
[ApiController]
[Route("api/[controller]")]
public class DishesController : ControllerBase
{
[HttpGet]
public async Task<IActionResult> GetAllRecipes()
{
var client = new RestClient($"https://www.themealdb.com/api/json/v1/1/search.php?s=");
var request = new RestRequest();
var response = await client.ExecuteAsync(request);
var mealList = JsonSerializer.Deserialize<Content>(response.Content);
return Ok(mealList.Meals);
}
}

To address the problems one at a time...
the moment I changed property ingredient1 from public to private, that ingredient in list will become null
Changing the access modifier affects both deserialization and serialization, so this cannot be used to only stop it from serializing the property. You should split the data models up into what you want to receive and what you want to expose/return.
there are so many ingredients, some of them are null by default, I don't want to add them if they are null
Addition to splitting up the data models you can handle this when mapping from one model to the other.
The following code should fix both issues:
namespace TheMealDb.Models
{
// These are the models you receive from TheMealDb
// JSON converted to classes with https://json2csharp.com/
public class Root
{
public List<Meal> meals { get; set; }
}
public class Meal
{
public string idMeal { get; set; }
public string strMeal { get; set; }
public string strIngredient1 { get; set; }
public string strIngredient2 { get; set; }
public string strIngredient3 { get; set; }
// Other properties removed for brevity...
}
}
namespace Internal.Models
{
// This is the model you want to return from your controller action
public class Meal
{
[JsonPropertyName("id")] // No need to use the same name as from themealdb
public string Id { get; set; }
[JsonPropertyName("name")]
public string Name { get; set; }
[JsonPropertyName("ingredients")]
public List<string> Ingredients { get; set; }
}
}
Now, to fetch, map and return the data in your controller action:
[HttpGet]
public async Task<IActionResult> GetAllRecipes()
{
var client = new RestClient($"https://www.themealdb.com/api/json/v1/1/search.php?s=");
var request = new RestRequest();
var response = await client.ExecuteAsync(request);
// Deserialize to the "TheMealDb" models
var mealList = JsonSerializer.Deserialize<TheMealDb.Models.Root>(response.Content);
// Map to your own models
var myMealList = mealDbList.meals?.Select(MapToInternal);
return Ok(myMealList);
}
// Map "TheMealDb" model to your own model
private Internal.Models.Meal MapToInternal(TheMealDb.Models.Meal externalMeal)
{
return new Internal.Models.Meal
{
Id = externalMeal.idMeal,
Name = externalMeal.strMeal,
Ingredients = new []
{
externalMeal.strIngredient1,
externalMeal.strIngredient2,
externalMeal.strIngredient3,
// ...
}
// Remove empty/null ingredients
.Where(ingr => !string.IsNullOrEmpty(ingr))
.ToList()
};
}
See the code in action.

Get json data from POST method in asp.net mvc

I got an error while getting json data from POST method, am I doing something wrong
C# Code:
public IActionResult signupapi(UserSignUp user)
{
var model = new Models.SignUpModelAPI(HttpContext);
if (user == null)
{
return Content(model.ResponseJsonText(false, string.Format(model.Language("empty"),
HttpContext.Request.Method, HttpContext.Request.Path.Value), Class.CodeResponse.ERROR), new Microsoft.Net.Http.Headers.MediaTypeHeaderValue("application/json"));
}
if (!model.isAllowMethod("POST"))
{
return Content(model.ResponseJsonText(false,string.Format(model.Language("notallowmethod"),
HttpContext.Request.Method,HttpContext.Request.Path.Value),Class.CodeResponse.ERROR),new Microsoft.Net.Http.Headers.MediaTypeHeaderValue("application/json"));
}
return Content(JsonConvert.SerializeObject(user));
}
public class UserSignUp
{
public string fullname { get; set; }
public string username { get; set; }
public string email { get; set; }
public string password { get; set; }
}
And this is the result when i try on reqbin every value i get is null

You need to add FromBody attribute to get your data for the POST operation:
public IActionResult signupapi([FromBody]UserSignUp user)
You can read more on parameter binding on MSDN docs.

.NET Core API REST C# List into List is null

I'm developing an api in net core.
I've done a post function in which I send an object containing multiple parameters and a list within another list.
When I'm debugging the code the function is called correctly but I find that the second list always arrives null.
The rest of the data arrives at you correctly. I have done different tests with other objects and everything works correctly.
It is this case in which the list within another the second one arrives null.
My code:
example request input
{
"Name": "TestName",
"Related1":
[{
"id1": "TestNameRelated1",
"Related2":
[{
"id2": "TestNameRelated2"
}]
}]
}
[HttpPost]
public resultExample Test([FromBody]TestClass test)
{
//do something
}
[DataContract]
public class TestClass
{
[DataMember]
public string Name { get; set; }
[DataMember]
public List<TestClassArray> Related1 { get; set; }
}
[DataContract]
public class TestClassArray
{
[DataMember]
public string id1 { get; set; }
[DataMember]
public List<TestClassArray2> Related2 { get; set; }
}
[DataContract]
public class TestClassArray2
{
[DataMember]
public string id2 { get; set; }
}
This api was previously made in .NET framework 4.8 and this case worked correctly.
Now I'm passing the api to .Net5.
Could it be that in .Net5 it is not allowed to pass lists within other lists?
Do you have to enable some kind of configuration to be able to do this now?

You need use class/DTO with constructor like shown below and you should be good to go. I have uploaded this sample API app's code working with .net5.0 on my GitHub here.
public class TestClass
{
public TestClass()
{
Related1 = new List<TestClassArray>();
}
public string Name { get; set; }
public List<TestClassArray> Related1 { get; set; }
}
public class TestClassArray
{
public TestClassArray()
{
Related2 = new List<TestClassArray2>();
}
public string id1 { get; set; }
public List<TestClassArray2> Related2 { get; set; }
}
public class TestClassArray2
{
public string id2 { get; set; }
}
public class ResultExample
{
public string StatusCode { get; set; }
public string Message { get; set; }
}
Controller Post Method
[HttpPost]
[ProducesResponseType(typeof(ResultExample), 200)]
public ResultExample Post([FromBody] TestClass test)
{
ResultExample testResult = new ResultExample();
TestClass test2 = new TestClass();
TestClassArray testClassArray = new TestClassArray();
TestClassArray2 testClassArray2 = new TestClassArray2();
test2.Name = test.Name;
foreach (var item in test.Related1)
{
foreach (var item2 in item.Related2)
{
testClassArray2.id2 = item2.id2;
}
testClassArray.Related2.Add(testClassArray2);
}
test2.Related1.Add(testClassArray);
Console.WriteLine(test2);
testResult.Message = "New Result added successfullly....";
testResult.StatusCode = "201";
return testResult;
}
Swagger Input Sample Payload
Post Controller Result
Response of Sample input payload,(You can change it to default 201 response code as well)

I had a similar issue.
API method shows List was null
In my case a date field was not well formatted
So I use SimpleDateFormat on Android Studio with a correct datetime format
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss",Locale.US);
item.setDate(dateFormat.format(calendar.getTime()));
and works fine

How to use json data in MVC view .cshtml

I hope someone can help me:
My challenge is, that I have a web service returning a json.
The format is
{"stations":[{"name":"aname","free":false},{"name":"anothername","free":true}]}
so I have one object which is an array that hold n objects with n attributes....
Now for each object in that array of the stations object I would like to render the attributes, like
<p>stations[0].name</p>
I need to use this in mvc.
So I created a model
public station(){}
public string name {get; set;}
public boolean free {get; set;}
in my contorller I use a WebClient and now I need to handle the response.
I was thinking of IEnumerable but I don't know how to put this in the view?!
my goal is to understand how i can do something like
public Actionresult Stations(){
var stations = JObject.Load(reponse);
return View(Stations);
}
but I have no idea how to the handle each object of the array and get their values in the Stations.cshtml view using for each or similar....
Any idea?

There are many ways to do that, this is my way.
Model
Create a class in which your JSON will be deserialized to:
public class RootJson
{
public IEnumerable<station> Stations { get; set; }
}
The RootJson class has a property which will contain a list of station's instances (your class):
public class station
{
public string name { get; set; }
public bool free { get; set; }
}
Controller
Then, deserialize your JSON using:
var deserialized = JsonConvert.DeserializeObject<RootJson>(json);
And pass the stations to the view:
return View(deserialized.Stations);
View
In your view you have to specify the type of the data passed, in this case IEnumerable<station>. So, at the top of your Stations.cshtml add:
#model IEnumerable<station>
You can use a foreach to iterate over the model:
#foreach(var station in Model)
{
<p>#station.name</p>
}
Edit: Full code for clarification
Model
RootJson.cs
public class RootJson
{
public IEnumerable<station> Stations { get; set; }
}
station.cs
public class station
{
public string name { get; set; }
public bool free { get; set; }
}
Controller
Inside YourController.cs
public ActionResult Stations() {
string json = YourMethodToGetJsonAsString();
var deserialized = JsonConvert.DeserializeObject<RootJson>(json);
return View(deserialized.Stations);
}
View
Stations.cshtml
#model IEnumerable<station>
#foreach(var station in Model)
{
<p>#station.name</p>
}

One of simplest way is to use ViewBag like this:
public ActionResult Stations()
{
string jsonString = "{ \"stations\":[{\"name\":\"aname\",\"free\":false},{\"name\":\"anothername\",\"free\":true}]}";
ViewBag.stations = ((dynamic)Newtonsoft.Json.JsonConvert.DeserializeObject(jsonString)).stations;
return View();
}
and inside cshtml for ex.
<p>#ViewBag.stations[0].name</p>

Model
public class Stations
{
public List<Station> Station { get; set; }
}
public class Station
{
public string Name { get; set; }
public bool Free { get; set; }
}
Controller
// Deserialising JSON
var station = JsonConvert.DeserializeObject<Stations>(response);
// Pass result to view
return View(station.Station);
View
At the top of your Stations.cshtml add:
#model IEnumerable<Station>
You can use a foreach to iterate over the model:
#foreach(var station in Model)
{
<p>#station.Name</p>
}

RESTSharp: Access values from deserialized class

I am using RESTSharp to receive and deserialize result from an API call. Response is JSON. I've created a class for the repsonse that looks like this:
public class JsonResponseClass
{
public class Selector
{
public static string verb { get; set; }
}
public class Points
{
public int definition { get; set; }
}
}
I do following to get the response:
var response = client.Execute<JsonResponseClass>(request);
var resData = response.Data;
How do I read/print values received from above? For example how do I print values verb and definition from the above deserialized response?

You're not supposed to nest the classes. Instead, add a property of each type to the root object's class.
public class JsonResponseClass
{
public Selector selector { get; set; }
public Points points { get; set; }
}
public class Selector
{
public static string verb { get; set; }
}
public class Points
{
public int definition { get; set; }
}
With that in place, the code works as expected:
var response = client.Execute<JsonResponseClass>(request);
var resData = response.Data;
var verb = resData.selector.verb;
var definition = resData.points.definition;

It's not clear what are you asking.
resData variable contains data from request stored in JsonResponseClass so you need to access it's fields like:
string verb = resData.verb;
Console.WriteLine(verb);