Best way to deserialize a nested list in a json - C#

Question

I got this Json:

{
    "CountriesAndCities": [
        {
            "CountryId": 2,
            "CountryName": "Chile",
            "CountryISOA3": "CHL",
            "Cities": [
                {
                    "CityId": 26,
                    "CityName": "Gran Santiago",
                    "Country": null
                },
                {
                    "CityId": 27,
                    "CityName": "Gran Concepción",
                    "Country": null
                }
            ]
        }
    ]
}

As you can see, it's a lists of objects, and those objects have another list nested.

I've got these models:

public class City
    {
        public int CityId { get; set; }
        public string CityName { get; set; }
        public Country Country { get; set; }
    }

    public class Country
    {
        public int CountryId { get; set; }
        public string CountryName { get; set; }
        public string CountryISOA3 { get; set; }
        public ICollection<City> Cities { get; set; }
    }

Right now, this does the trick:

public ICollection<Country> Countries { get; set; }

        public RegionViewModel()
        {
            // Pidiendo las ciudades al backend.
            S3EWebApi webApi = new S3EWebApi();
            HttpResponseMessage response = webApi.Get("/api/Benefits/GetCountriesAndCities");
            string jsonResponseString = response.Content.ReadAsStringAsync().Result;
            JObject jsonResponse = JsonConvert.DeserializeObject<JObject>(jsonResponseString);

            string countriesAndCitiesJSon = jsonResponse["CountriesAndCities"].ToString();
            Countries = JsonConvert.DeserializeObject<List<Country>>(countriesAndCitiesJSon);
        }

But I don't know, I think that's way too far from elegant. Is there a better approach to it? Thanks. :)

Answer 1

Make a wrapper class for the response.

public class CountriesAndCitiesResponse
{
    public List<Country> CountriesAndCities { get; set; }
}

Then use it like so:

public RegionViewModel()
{
    // Pidiendo las ciudades al backend.
    S3EWebApi webApi = new S3EWebApi();
    HttpResponseMessage response = webApi.Get("/api/Benefits/GetCountriesAndCities");
    string jsonResponseString = response.Content.ReadAsStringAsync().Result;
    CountriesAndCitiesResponse response = JsonConvert.DeserializeObject<CountriesAndCitiesResponse>(jsonResponseString);

    Countries = response.CountriesAndCities;
}

Also you should re-think calling an async method in a constructor (it could lead to deadlocks). You might consider having the call in an async Task Load() method instead and calling that after calling the constructor.

Answer 2

Generally speaking you should never need to deserialize twice. The simplest solution is to make a class to represent the outermost part of the JSON and then deserialize into that as shown in @Alex Wiese's answer .

If you want to deserialize without a root class then you can use the ToObject<T>() method after you have deserialized into the JObject .

JObject jsonResponse = JsonConvert.DeserializeObject<JObject>(jsonResponseString);
Countries = jsonResponse["CountriesAndCities"].ToObject<List<Country>>();