sharee.bike-App/TINKLib/ViewModel/FeesAndBikes/FeesAndBikesPageViewModel.cs

using System.ComponentModel;
using Xamarin.Forms;
using System.Threading.Tasks;

namespace TINK.ViewModel.Contact
{
    public class FeesAndBikesPageViewModel : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;


        /// <summary> Holds value wether site caching is on or off.</summary>
        bool IsSiteCachingOn { get; }

        private string FeesResourcePath { get; }

        private string BikesResourcePath { get; }


        /// <summary> Constructs view model.</summary>
        /// <param name="isSiteCachingOn">Set of user permissions</param>
        /// <param name="resourceProvider">Delegate to get an an embedded html ressource. Used as fallback if download from web page does not work and cache is empty.</param>
        public FeesAndBikesPageViewModel(
            string hostName,
            string feesResourcePath,
            string bikesResourcePath,
            bool isSiteCachingOn)
        {
            HostName = hostName;
            FeesResourcePath = feesResourcePath;
            BikesResourcePath = bikesResourcePath;
            IsSiteCachingOn = isSiteCachingOn;
        }

        /// <summary> Holds the name of the host.</summary>
        private string HostName { get; }

        /// <summary> Called when page is shown. </summary>
        public async void OnAppearing()
        {
            RentBikeText = new HtmlWebViewSource
            {
                Html = !string.IsNullOrEmpty(FeesResourcePath)
                    ? await ViewModelHelper.GetSource($"https://{HostName}/{FeesResourcePath}" /* "site/tariff_info_1.html" */, IsSiteCachingOn)
                    : await Task.FromResult(ViewModelHelper.FromBody("No fees resource available. Resource path is null or empty."))
            };

            TypesOfBikesText = new HtmlWebViewSource 
            {
                Html = !string.IsNullOrEmpty(BikesResourcePath)
                    ? await ViewModelHelper.GetSource($"https://{HostName}/{BikesResourcePath}" /*"site/bike_info.html"*/, IsSiteCachingOn)
                    : await Task.FromResult(ViewModelHelper.FromBody("No bikes instruction resource available. Resource path is null or empty."))
            };
        }

        private HtmlWebViewSource rentBikeText;

        private HtmlWebViewSource typesOfBikesText;

        public HtmlWebViewSource RentBikeText
        {
            get => rentBikeText;
            set
            {
                rentBikeText = value;
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(RentBikeText)));
            }
        }

        public HtmlWebViewSource TypesOfBikesText
        {
            get => typesOfBikesText;
            set
            {
                typesOfBikesText = value;
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(TypesOfBikesText)));
            }
        }
    }
}