borepin/Borepin/Borepin/Base/ConnectionModelBase.cs

using Borepin.Service.BFFH;
using Borepin.Service.BFFH.Exceptions;
using Prism.Navigation;
using Prism.Services;
using System.Threading.Tasks;
using Xamarin.Forms;

namespace Borepin.Base
{
    /// <summary>
    /// Base for all BFFH Based PageModels
    /// </summary>
    public abstract class ConnectionModelBase : PageModelBase
    {
        #region Private Fields
        protected readonly IPageDialogService _PageDialogService;
        protected readonly IBFFHService _BFFHService;
        #endregion

        #region Constructors
        protected ConnectionModelBase(INavigationService navigationService, IPageDialogService pageDialogService, IBFFHService bFFHService) : base(navigationService)
        {
            _PageDialogService = pageDialogService;
            _BFFHService = bFFHService;
        }
        #endregion

        #region Fields
        /// <summary>
        /// PageModel is Connected
        /// </summary>
        private bool _IsConnected = true;
        public bool IsConnected
        {
            get => _IsConnected;
            set => SetProperty(ref _IsConnected, value);
        }
        #endregion

        #region Methods
        /// <summary>
        /// Checks connection to Server.
        /// Display message if Connection is lost.
        /// </summary>
        /// <returns>True if connection is ok.</returns>
        public async Task<bool> CheckConnection()
        {
            try
            {
                if(_BFFHService.CurrentConnection != null && !_BFFHService.IsConnected)
                {
                    await _BFFHService.Reconnect().ConfigureAwait(false);
                }
                else if(_BFFHService.CurrentConnection == null)
                {
                    return false;
                }

                return true;
            }
            catch (ReconnectingFailedException)
            {
                Device.BeginInvokeOnMainThread(async () =>
                {
                    await _PageDialogService.DisplayAlertAsync("Connection failed", "Lost connection to server.", "Ok").ConfigureAwait(false);
                });

                IsConnected = false;
                return false;
            }
        }
        #endregion
    }
}