Load calendar appoinments data from JSON

Environment

Product Version	2019.3.1004.1
Product	Calendar for Xamarin

Description

This article shows how to deserialize appointment objects from JSON.

Solution

First, download NuGet packages for NewtonSoft library. More information about NewtonSoft can be found here.

Create new JSON file with name "Source.json" to our project and change its Build Action to "Embedded resource".

Here is a sample how our JSON file is stuctured.

[
  {
    "Title": "Meeting with Tom",
    "Detail": "Sea Garden",
    "StartDate": "2019-10-07T00:00:00Z",
    "EndDate": "2019-10-07T01:00:00Z",
    "Color":  "Red",
    "IsAllDay": true
  },
  {
    "Title": "Lunch with Sara",
    "Detail": "Restaurant",
    "StartDate": "2019-10-08T00:00:00Z",
    "EndDate": "2019-10-08T01:00:00Z",
    "Color": "Blue",
    "IsAllDay": true
  },
  {
    "Title": "Elle Birthday",
    "StartDate": "2019-10-09T00:00:00Z",
    "EndDate": "2019-10-09T01:00:00Z",
    "Color": "Green",
    "IsAllDay": false
  }
]

Add the RadCalendar in the Main.xaml file.

<telerikInput:RadCalendar x:Name="calendar"/>

After that lets create a class that will convert inconsistent JSON data like Colors.

public class AppointmentJsonConverter : JsonConverter<Appointment>
{
    public override Appointment ReadJson(JsonReader reader, Type objectType, Appointment existingValue, bool hasExistingValue, JsonSerializer serializer)
    {
        JObject jObject = JObject.Load(reader);
        var title = jObject["Title"].Value<string>();
        String detail = null;
        if (jObject["Detail"] != null)
        {
            detail = jObject["Detail"].Value<string>();
        }

        var startDate = jObject["StartDate"].Value<DateTime>();
        var endDate = jObject["EndDate"].Value<DateTime>();

        var colorTypeConverter = new ColorTypeConverter();
        var color = (Color)colorTypeConverter.ConvertFromInvariantString(jObject["Color"].Value<string>());

        return new Appointment()
        {
            Title = title,
            Detail = detail,
            StartDate = startDate,
            EndDate = endDate,
            Color = color
        };
    }

    public override void WriteJson(JsonWriter writer, Appointment value, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }
}

Finally, create a method named "GetJsonData()" which uses NewtonSoft library and deserializes the appointment objects in it.

public partial class MainPage : ContentPage
{
    public MainPage()
    {
        InitializeComponent();
        this.GetJsonData();
    }

    private void GetJsonData()
    {
        string jsonFileName = "Source.json";
        ObservableCollection<Appointment> objAppointmentList = new ObservableCollection<Appointment>();
        var assembly = typeof(MainPage).GetTypeInfo().Assembly;
        Stream stream = assembly.GetManifestResourceStream($"{assembly.GetName().Name}.{jsonFileName}");
        using (var reader = new System.IO.StreamReader(stream))
        {
            var jsonString = reader.ReadToEnd();
            objAppointmentList = JsonConvert.DeserializeObject<ObservableCollection<Appointment>>(jsonString, new AppointmentJsonConverter());
        }
        this.calendar.AppointmentsSource = objAppointmentList;
    }
}