How to consume data from url in application - mvvm

Question

I'm trying to get some json file from url using service and show them in my application.
Here's how my code looks like now...
Model:
public class IrrigNetModel
{
public int Id { get; set; }
public string Message { get; set; }
public DateTime Date { get; set; }
public string DateText { get; set; }
public int StationId { get; set; }
public string StationName { get; set; }
public float StationLongitude { get; set; }
public float StationLatitude { get; set; }
public int ServiceId { get; set; }
public string ServiceName { get; set; }
}
View:
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class IrrigNetPage : ContentPage
{
public IrrigNetPage()
{
InitializeComponent();
BindingContext = new IrrigNetViewModel();
}
}
ViewModel
//ServicesModel irrigNetModel = new ServicesModel()
//{
// Id = 1,
// Message = "sample string 2",
// Date = DateTime.Now,
// DateText = "sample string 4",
// StationId = 5,
// StationName = "sample string 6",
// StationLongitude = 1,
// StationLatitude = 1,
// ServiceId = 7,
// ServiceName = "sample string 8"
//};
//public IrrigNetViewModel(ServicesModel services)
//{
// irrigNetModel.Id = services.Id;
// irrigNetModel.Message = services.Message;
// irrigNetModel.Date = services.Date;
// irrigNetModel.DateText = services.DateText;
// irrigNetModel.StationId = services.StationId;
// irrigNetModel.StationName = services.StationName;
// irrigNetModel.StationLongitude = services.StationLongitude;
// irrigNetModel.StationLatitude = services.StationLatitude;
// irrigNetModel.ServiceId = services.ServiceId;
// irrigNetModel.ServiceName = services.ServiceName;
//}
public ObservableCollection<IrrigNetModel> IrrigNetCollection { get; set; } = new ObservableCollection<IrrigNetModel>
{
new IrrigNetModel
{
StationId = 1,
StationName = "Krakatosia",
Message = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur scelerisque a lorem sit amet mattis.",
DateText = "21.07.2012."
}
};
public IrrigNetViewModel()
{
IrrigNetService.GetServices("TOKEN", "sr");
TabTappedCommand = new Command((tabName) => OnTapClicked(tabName.ToString()));
HideListOnTapCommand = new Command(HideListOnTap);
IrrigNetModel model = new IrrigNetModel();
//ShowIrrigNetDetailPageCommand = new Command(ShowDetailPage);
var irrigNetModel = new IrrigNetModel
{
//StationName = model.StationName,
//Message = model.Message,
//DateText = model.DateText
StationId = 1,
Message = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur scelerisque a lorem sit amet mattis.",
DateText = "03.07.2021."
};
IrrigNetCollection.Add(irrigNetModel);
}
In ViewModel you can see all what I have tried to show data but currnetly it's hardcoded for testing purpose (just to see how my page looks like with some data).
And, of course here is my service:
class IrrigNetService
{
public static async Task<IrrigNetModel> GetServices(string token, string lngCode)
{
string url = DataURL.BASE_URL + "ekonetmobile/getlistnotifications?lngCode={" + lngCode + "}";
IrrigNetModel model = new IrrigNetModel();
try
{
using(var client = new HttpClient())
{
client.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "application/json");
client.DefaultRequestHeaders.TryAddWithoutValidation("Authorization", token);
client.DefaultRequestHeaders.TryAddWithoutValidation("Culture", LocalData.Lang);
string content = Newtonsoft.Json.JsonConvert.SerializeObject(model);
HttpResponseMessage result = await client.PostAsync(url, new StringContent(content, Encoding.UTF8, "application/json"));
if (result.StatusCode == System.Net.HttpStatusCode.OK)
{
string resultContent = await result.Content.ReadAsStringAsync();
model = (IrrigNetModel)Newtonsoft.Json.JsonConvert.DeserializeObject(resultContent.ToString(), typeof(IrrigNetModel));
}
else if (result.StatusCode == System.Net.HttpStatusCode.Unauthorized)
{
}
}
}
catch (Exception)
{
model = null;
}
return model;
}
}
POST api/ekonetmobile/getlistnotifications?lngCode={lngCode}
Currently my service show:
{StatusCode: 401, ReasonPhrase: 'Unauthorized', Version: 1.1, Content: System.Net.Http.StreamContent, Headers:
{
Cache-Control: no-cache
Date: Tue, 14 May 2019 12:03:14 GMT
Pragma: no-cache
Server: Microsoft-IIS/8.5
WWW-Authenticate: Bearer
X-Android-Received-Millis: 1557835393828
X-Android-Response-Source: NETWORK 401
X-Android-Selected-Protocol: http/1.1
X-Android-Sent-Millis: 1557835393651
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
Content-Length: 61
Content-Type: application/json; charset=utf-8
Expires: -1
}}
So, the point is to set value in 'StationName', 'Message', 'DateText' etc, etc from json, instead of "Lorem ipsum dolor sit amet..." and other constant values...

Answer 1

Solution:
I created new class:
public class LocalData
{
public static string Token
{
get
{
return CrossSecureStorage.Current.GetValue("TOKEN");
}
set
{
CrossSecureStorage.Current.SetValue("TOKEN", value);
}
}
}
Then, edited LoginViewModel like this:
class LoginViewModel
{
public string Username { get; set; }
public string Password { get; set; }
public Command LoginCommand => new Command(async () =>
{
LoginModel model = new LoginModel(Username, Password);
if (model.CheckInformation())
{
AccountResponseModel response = await LoginService.Login(model);
if (!string.IsNullOrEmpty(response.Token))
{
await Application.Current.MainPage.DisplayAlert("Prijavljivanje", "Uspešno ste se prijavili", "OK.");
LocalData.Token = response.Token;
Application.Current.MainPage = new AgroNetMasterPage();
}
else
{
await Application.Current.MainPage.DisplayAlert("Prijavljivanje", "Prijava neuspešna. Netačno ime ili lozinka", "OK.");
}
}
else
{
await Application.Current.MainPage.DisplayAlert("Prijavljivanje", "Prijava neuspešna. Netačno ime ili lozinka", "OK.");
}
});
}
As zou can se I set Token in LocalData
LocalData.Token = response.Token;
Also, here is AccountResponseModel:
public class AccountResponseModel
{
public string Token { get; set; }
public string RoleId { get; set; }
public string UserId { get; set; }
}
After all my service now looks little bit diferent:
class IrrigNetService
{
public static async Task<IrrigNetModel> GetServices(string token, string lngCode)
{
IrrigNetModel model = new IrrigNetModel();
try
{
string URL = DataURL.BASE_URL + "agronetmobile/getlistnotifications?lngCode=" + lngCode;
string content = Newtonsoft.Json.JsonConvert.SerializeObject(model);
using (var client = new HttpClient())
{
client.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "application/json");
client.DefaultRequestHeaders.TryAddWithoutValidation("Authorization", token);
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
//client.DefaultRequestHeaders.TryAddWithoutValidation("Culture", LocalData.Lang);
HttpResponseMessage result = await client.PostAsync(URL, new StringContent(content, Encoding.UTF8, "application/json"));
if (result.StatusCode == System.Net.HttpStatusCode.OK)
{
string resultContent = await result.Content.ReadAsStringAsync();
model = (IrrigNetModel)Newtonsoft.Json.JsonConvert.DeserializeObject(resultContent, typeof(IrrigNetModel));
}
else if (result.StatusCode == System.Net.HttpStatusCode.Unauthorized)
{
//
}
}
}
catch (Exception ex)
{
model = null;
}
return model;
}
}