Restructure application to show better use of .WithParentWindowOrActi… (

#112)

* Restructure application to show better use of .WithParentWindowOrActivity(func)

* Fix iOS

UserDetailsClient/UserDetailsClient.Core/Features/LogOn/B2CAuthenticationService.cs

@@ -5,34 +5,55 @@
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using Xamarin.Forms;
 
 namespace UserDetailsClient.Core.Features.LogOn
 {
-    public class B2CAuthenticationService : IAuthenticationService
+    /// <summary>
+    ///  For simplicity, we'll have this as a singleton. 
+    /// </summary>
+    public class B2CAuthenticationService
     {
-        public IPublicClientApplication PCA = null;
+        private readonly IPublicClientApplication _pca;
 
-        public object ParentActivityOrWindow { get; set; }
 
-        public B2CAuthenticationService()
+        private static readonly Lazy<B2CAuthenticationService> lazy = new Lazy<B2CAuthenticationService>
+           (() => new B2CAuthenticationService());
+
+        public static B2CAuthenticationService Instance { get { return lazy.Value; } }
+
+
+        private B2CAuthenticationService()
         {
+
             // default redirectURI; each platform specific project will have to override it with its own
-            PCA = PublicClientApplicationBuilder.Create(B2CConstants.ClientID)
+            var builder = PublicClientApplicationBuilder.Create(B2CConstants.ClientID)
                 .WithB2CAuthority(B2CConstants.AuthoritySignInSignUp)
                 .WithIosKeychainSecurityGroup(B2CConstants.IOSKeyChainGroup)
-                .WithRedirectUri($"msal{B2CConstants.ClientID}://auth")
-                .Build();
+                .WithRedirectUri($"msal{B2CConstants.ClientID}://auth");
+
+            // Android implementation is based on https://github.com/jamesmontemagno/CurrentActivityPlugin
+            // iOS implementation would require to expose the current ViewControler - not currently implemented as it is not required
+            // UWP does not require this
+            var windowLocatorService = DependencyService.Get<IParentWindowLocatorService>();
+
+            if (windowLocatorService != null)
+            {
+                builder = builder.WithParentActivityOrWindow(() => windowLocatorService?.GetCurrentParentWindow());
+            }
+
+            _pca = builder.Build();
         }
 
         public async Task<UserContext> SignInAsync()
         {
-            UserContext newContext = null;
+            UserContext newContext;
             try
             {
                 // acquire token silent
                 newContext = await AcquireToken();
             }
-            catch (MsalUiRequiredException ex)
+            catch (MsalUiRequiredException)
             {
                 // acquire token interactive
                 newContext = await SignInInteractively();
@@ -42,8 +63,8 @@ public async Task<UserContext> SignInAsync()
 
         private async Task<UserContext> AcquireToken()
         {
-            IEnumerable<IAccount> accounts = await PCA.GetAccountsAsync();
-            AuthenticationResult authResult = await PCA.AcquireTokenSilent(B2CConstants.Scopes, GetAccountByPolicy(accounts, B2CConstants.PolicySignUpSignIn))
+            IEnumerable<IAccount> accounts = await _pca.GetAccountsAsync();
+            AuthenticationResult authResult = await _pca.AcquireTokenSilent(B2CConstants.Scopes, GetAccountByPolicy(accounts, B2CConstants.PolicySignUpSignIn))
                .WithB2CAuthority(B2CConstants.AuthoritySignInSignUp)
                .ExecuteAsync();
 
@@ -53,10 +74,9 @@ private async Task<UserContext> AcquireToken()
 
         public async Task<UserContext> ResetPasswordAsync()
         {
-            AuthenticationResult authResult = await PCA.AcquireTokenInteractive(B2CConstants.Scopes)
+            AuthenticationResult authResult = await _pca.AcquireTokenInteractive(B2CConstants.Scopes)
                 .WithPrompt(Prompt.NoPrompt)
                 .WithAuthority(B2CConstants.AuthorityPasswordReset)
-                .WithParentActivityOrWindow(ParentActivityOrWindow)
                 .ExecuteAsync();
 
             var userContext = UpdateUserInfo(authResult);
@@ -66,13 +86,12 @@ public async Task<UserContext> ResetPasswordAsync()
 
         public async Task<UserContext> EditProfileAsync()
         {
-            IEnumerable<IAccount> accounts = await PCA.GetAccountsAsync();
+            IEnumerable<IAccount> accounts = await _pca.GetAccountsAsync();
 
-            AuthenticationResult authResult = await PCA.AcquireTokenInteractive(B2CConstants.Scopes)
+            AuthenticationResult authResult = await _pca.AcquireTokenInteractive(B2CConstants.Scopes)
                 .WithAccount(GetAccountByPolicy(accounts, B2CConstants.PolicyEditProfile))
                 .WithPrompt(Prompt.NoPrompt)
                 .WithAuthority(B2CConstants.AuthorityEditProfile)
-                .WithParentActivityOrWindow(ParentActivityOrWindow)
                 .ExecuteAsync();
 
             var userContext = UpdateUserInfo(authResult);
@@ -82,11 +101,10 @@ public async Task<UserContext> EditProfileAsync()
 
         private async Task<UserContext> SignInInteractively()
         {
-            IEnumerable<IAccount> accounts = await PCA.GetAccountsAsync();
+            IEnumerable<IAccount> accounts = await _pca.GetAccountsAsync();
 
-            AuthenticationResult authResult = await PCA.AcquireTokenInteractive(B2CConstants.Scopes)
+            AuthenticationResult authResult = await _pca.AcquireTokenInteractive(B2CConstants.Scopes)
                 .WithAccount(GetAccountByPolicy(accounts, B2CConstants.PolicySignUpSignIn))
-                .WithParentActivityOrWindow(ParentActivityOrWindow)
                 .ExecuteAsync();
 
             var newContext = UpdateUserInfo(authResult);
@@ -96,11 +114,11 @@ private async Task<UserContext> SignInInteractively()
         public async Task<UserContext> SignOutAsync()
         {
 
-            IEnumerable<IAccount> accounts = await PCA.GetAccountsAsync();
+            IEnumerable<IAccount> accounts = await _pca.GetAccountsAsync();
             while (accounts.Any())
             {
-                await PCA.RemoveAsync(accounts.FirstOrDefault());
-                accounts = await PCA.GetAccountsAsync();
+                await _pca.RemoveAsync(accounts.FirstOrDefault());
+                accounts = await _pca.GetAccountsAsync();
             }
             var signedOutContext = new UserContext();
             signedOutContext.IsLoggedOn = false;
@@ -165,10 +183,5 @@ JObject ParseIdToken(string idToken)
             idToken = Base64UrlDecode(idToken);
             return JObject.Parse(idToken);
         }
-
-        public void SetParent(object parent)
-        {
-            ParentActivityOrWindow = parent;
-        }
     }
 }

UserDetailsClient/UserDetailsClient.Core/Features/LogOn/IParentWindowLocatorService.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace UserDetailsClient.Core.Features.LogOn
+{
+    /// <summary>
+    /// Simple platform specific service that is responsible for locating a 
+    /// </summary>
+    public interface IParentWindowLocatorService
+    {
+       object GetCurrentParentWindow();
+    }
+}

UserDetailsClient/UserDetailsClient.Core/MainPage.xaml.cs

@@ -8,19 +8,9 @@ namespace UserDetailsClient.Core
 {
     public partial class MainPage : ContentPage
     {
-        protected readonly IAuthenticationService authenticationService;
-
         public MainPage()
         {
             InitializeComponent();
-
-            /* Grab an instance of the IAuthenticationService using DependencyService.
-             * 
-             * NOTE: this will give us an instance of B2CAuthenticationService 
-             * because we registered that class in App.xaml.cs
-             * 
-             * */
-            authenticationService = DependencyService.Get<IAuthenticationService>();
         }
 
         async void OnSignInSignOut(object sender, EventArgs e)
@@ -29,13 +19,13 @@ async void OnSignInSignOut(object sender, EventArgs e)
             {
                 if (btnSignInSignOut.Text == "Sign in")
                 {
-                    var userContext = await authenticationService.SignInAsync();
+                    var userContext = await B2CAuthenticationService.Instance.SignInAsync();
                     UpdateSignInState(userContext);
                     UpdateUserInfo(userContext);
                 }
                 else
                 {
-                    var userContext = await authenticationService.SignOutAsync();
+                    var userContext = await B2CAuthenticationService.Instance.SignOutAsync();
                     UpdateSignInState(userContext);
                     UpdateUserInfo(userContext);
                 }
@@ -47,7 +37,7 @@ async void OnSignInSignOut(object sender, EventArgs e)
                 // reset and not any other error.
                 if (ex.Message.Contains("AADB2C90118"))
                     OnPasswordReset();
-                // Alert if any exception excluding user cancelling sign-in dialog
+                // Alert if any exception excluding user canceling sign-in dialog
                 else if (((ex as MsalException)?.ErrorCode != "authentication_canceled"))
                     await DisplayAlert($"Exception:", ex.ToString(), "Dismiss");
             }
@@ -57,7 +47,7 @@ async void OnCallApi(object sender, EventArgs e)
             try
             {
                 lblApi.Text = $"Calling API {App.ApiEndpoint}";
-                var userContext = await authenticationService.SignInAsync();
+                var userContext = await B2CAuthenticationService.Instance.SignInAsync();
                 var token = userContext.AccessToken;
 
                 // Get data from API
@@ -89,13 +79,13 @@ async void OnEditProfile(object sender, EventArgs e)
         {
             try
             {
-                var userContext = await authenticationService.EditProfileAsync();
+                var userContext = await B2CAuthenticationService.Instance.EditProfileAsync();
                 UpdateSignInState(userContext);
                 UpdateUserInfo(userContext);
             }
             catch (Exception ex)
             {
-                // Alert if any exception excludig user cancelling sign-in dialog
+                // Alert if any exception excluding user canceling sign-in dialog
                 if (((ex as MsalException)?.ErrorCode != "authentication_canceled"))
                     await DisplayAlert($"Exception:", ex.ToString(), "Dismiss");
             }
@@ -104,13 +94,13 @@ async void OnResetPassword(object sender, EventArgs e)
         {
             try
             {
-                var userContext = await authenticationService.ResetPasswordAsync();
+                var userContext = await B2CAuthenticationService.Instance.ResetPasswordAsync();
                 UpdateSignInState(userContext);
                 UpdateUserInfo(userContext);
             }
             catch (Exception ex)
             {
-                // Alert if any exception excludig user cancelling sign-in dialog
+                // Alert if any exception excluding user canceling sign-in dialog
                 if (((ex as MsalException)?.ErrorCode != "authentication_canceled"))
                     await DisplayAlert($"Exception:", ex.ToString(), "Dismiss");
             }
@@ -119,13 +109,13 @@ async void OnPasswordReset()
         {
             try
             {
-                var userContext = await authenticationService.ResetPasswordAsync();
+                var userContext = await B2CAuthenticationService.Instance.ResetPasswordAsync();
                 UpdateSignInState(userContext);
                 UpdateUserInfo(userContext);
             }
             catch (Exception ex)
             {
-                // Alert if any exception excludig user cancelling sign-in dialog
+                // Alert if any exception excluding user canceling sign-in dialog
                 if (((ex as MsalException)?.ErrorCode != "authentication_canceled"))
                     await DisplayAlert($"Exception:", ex.ToString(), "Dismiss");
             }

UserDetailsClient/UserDetailsClient.Core/UserDetailsClient.Core.csproj

@@ -4,14 +4,16 @@
     <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
 
+  <ItemGroup>
+    <Compile Remove="Framework\**" />
+    <EmbeddedResource Remove="Framework\**" />
+    <None Remove="Framework\**" />
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="Newtonsoft.Json" Version="11.0.2" />
     <PackageReference Include="System.Net.Http" Version="4.3.3" />
     <PackageReference Include="Xamarin.Forms" Version="3.0.0.530893" />
     <PackageReference Include="Microsoft.Identity.Client" Version="4.6.0" />
   </ItemGroup>
-
-  <ItemGroup>
-    <Folder Include="Framework\" />
-  </ItemGroup>
 </Project>

UserDetailsClient/UserDetailsClient.Droid/AndroidParentWindowLocatorService.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+using Android.App;
+using Android.Content;
+using Android.OS;
+using Android.Runtime;
+using Android.Views;
+using Android.Widget;
+using Microsoft.Identity.Client;
+using Plugin.CurrentActivity;
+using UserDetailsClient.Core.Features.LogOn;
+
+namespace UserDetailsClient.Droid
+{
+    class AndroidParentWindowLocatorService : IParentWindowLocatorService
+    {
+        public object GetCurrentParentWindow()
+        {
+            return CrossCurrentActivity.Current.Activity;
+        }
+    }
+}

UserDetailsClient/UserDetailsClient.Droid/MainActivity.cs

@@ -7,6 +7,7 @@
 using UserDetailsClient.Core;
 using Xamarin.Forms;
 using UserDetailsClient.Core.Features.LogOn;
+using Plugin.CurrentActivity;
 
 namespace UserDetailsClient.Droid
 {
@@ -15,18 +16,17 @@ public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompa
     {
         protected override void OnCreate(Bundle bundle)
         {
+            CrossCurrentActivity.Current.Init(this, bundle);
+            DependencyService.Register<IParentWindowLocatorService, AndroidParentWindowLocatorService>();
+
             TabLayoutResource = Resource.Layout.Tabbar;
             ToolbarResource = Resource.Layout.Toolbar;
 
             base.OnCreate(bundle);
 
-            global::Xamarin.Forms.Forms.Init(this, bundle);
+            Forms.Init(this, bundle);
 
             LoadApplication(new App());
-
-            var authenticationService = DependencyService.Get<IAuthenticationService>();
-            // Default system browser
-            authenticationService.SetParent(this);
         }
 
         protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)