Components auth: basic services and components

src/Components/Components/ref/Microsoft.AspNetCore.Components.netstandard2.0.cs

@@ -3,6 +3,34 @@
 
 namespace Microsoft.AspNetCore.Components
 {
+    public partial class AuthenticationState
+    {
+        public AuthenticationState(System.Security.Claims.ClaimsPrincipal user) { }
+        public System.Security.Claims.ClaimsPrincipal User { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
+    }
+    public delegate void AuthenticationStateChangedHandler(System.Threading.Tasks.Task<Microsoft.AspNetCore.Components.AuthenticationState> task);
+    public abstract partial class AuthenticationStateProvider
+    {
+        protected AuthenticationStateProvider() { }
+        public event Microsoft.AspNetCore.Components.AuthenticationStateChangedHandler AuthenticationStateChanged { add { } remove { } }
+        public abstract System.Threading.Tasks.Task<Microsoft.AspNetCore.Components.AuthenticationState> GetAuthenticationStateAsync();
+        protected void NotifyAuthenticationStateChanged(System.Threading.Tasks.Task<Microsoft.AspNetCore.Components.AuthenticationState> task) { }
+    }
+    public partial class AuthorizeView : Microsoft.AspNetCore.Components.ComponentBase
+    {
+        public AuthorizeView() { }
+        [Microsoft.AspNetCore.Components.ParameterAttribute]
+        public Microsoft.AspNetCore.Components.RenderFragment<Microsoft.AspNetCore.Components.AuthenticationState> Authorized { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
+        [Microsoft.AspNetCore.Components.ParameterAttribute]
+        public Microsoft.AspNetCore.Components.RenderFragment Authorizing { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
+        [Microsoft.AspNetCore.Components.ParameterAttribute]
+        public Microsoft.AspNetCore.Components.RenderFragment<Microsoft.AspNetCore.Components.AuthenticationState> ChildContent { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
+        [Microsoft.AspNetCore.Components.ParameterAttribute]
+        public Microsoft.AspNetCore.Components.RenderFragment NotAuthorized { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
+        protected override void BuildRenderTree(Microsoft.AspNetCore.Components.RenderTree.RenderTreeBuilder builder) { }
+        [System.Diagnostics.DebuggerStepThroughAttribute]
+        protected override System.Threading.Tasks.Task OnParametersSetAsync() { throw null; }
+    }
     [Microsoft.AspNetCore.Components.BindElementAttribute("select", null, "value", "onchange")]
     [Microsoft.AspNetCore.Components.BindElementAttribute("textarea", null, "value", "onchange")]
     [Microsoft.AspNetCore.Components.BindInputElementAttribute("checkbox", null, "checked", "onchange")]
@@ -57,6 +85,15 @@ public static partial class BindMethods
         public static System.Action<Microsoft.AspNetCore.Components.UIEventArgs> SetValueHandler(System.Action<string> setter, string existingValue) { throw null; }
         public static System.Action<Microsoft.AspNetCore.Components.UIEventArgs> SetValueHandler<T>(System.Action<T> setter, T existingValue) { throw null; }
     }
+    public partial class CascadingAuthenticationState : Microsoft.AspNetCore.Components.ComponentBase, System.IDisposable
+    {
+        public CascadingAuthenticationState() { }
+        [Microsoft.AspNetCore.Components.ParameterAttribute]
+        public Microsoft.AspNetCore.Components.RenderFragment ChildContent { [System.Runtime.CompilerServices.CompilerGeneratedAttribute]get { throw null; } }
+        protected override void BuildRenderTree(Microsoft.AspNetCore.Components.RenderTree.RenderTreeBuilder builder) { }
+        protected override void OnInit() { }
+        void System.IDisposable.Dispose() { }
+    }
     [System.AttributeUsageAttribute(System.AttributeTargets.Property, AllowMultiple=false, Inherited=false)]
     public sealed partial class CascadingParameterAttribute : System.Attribute
     {

src/Components/Components/src/Auth/AuthenticationState.cs

@@ -0,0 +1,28 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Security.Claims;
+
+namespace Microsoft.AspNetCore.Components
+{
+    /// <summary>
+    /// Provides information about the currently authenticated user, if any.
+    /// </summary>
+    public class AuthenticationState
+    {
+        /// <summary>
+        /// Gets a <see cref="ClaimsPrincipal"/> that describes the current user.
+        /// </summary>
+        public ClaimsPrincipal User { get; }
+
+        /// <summary>
+        /// Constructs an instance of <see cref="AuthenticationState"/>.
+        /// </summary>
+        /// <param name="user">A <see cref="ClaimsPrincipal"/> representing the user.</param>
+        public AuthenticationState(ClaimsPrincipal user)
+        {
+            User = user ?? throw new ArgumentNullException(nameof(user));
+        }
+    }
+}

src/Components/Components/src/Auth/AuthenticationStateProvider.cs

@@ -0,0 +1,49 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Threading.Tasks;
+
+namespace Microsoft.AspNetCore.Components
+{
+    /// <summary>
+    /// Provides information about the authentication state of the current user.
+    /// </summary>
+    public abstract class AuthenticationStateProvider
+    {
+        /// <summary>
+        /// Gets an <see cref="AuthenticationState"/> instance that describes
+        /// the current user.
+        /// </summary>
+        /// <returns>An <see cref="AuthenticationState"/> instance that describes the current user.</returns>
+        public abstract Task<AuthenticationState> GetAuthenticationStateAsync();
+
+        /// <summary>
+        /// An event that provides notification when the <see cref="AuthenticationState"/>
+        /// has changed. For example, this event may be raised if a user logs in or out.
+        /// </summary>
+#pragma warning disable 0067 // "Never used" (it's only raised by subclasses)
+        public event AuthenticationStateChangedHandler AuthenticationStateChanged;
+#pragma warning restore 0067
+
+        /// <summary>
+        /// Raises the <see cref="AuthenticationStateChanged"/> event.
+        /// </summary>
+        /// <param name="task">A <see cref="Task"/> that supplies the updated <see cref="AuthenticationState"/>.</param>
+        protected void NotifyAuthenticationStateChanged(Task<AuthenticationState> task)
+        {
+            if (task == null)
+            {
+                throw new ArgumentNullException(nameof(task));
+            }
+
+            AuthenticationStateChanged?.Invoke(task);
+        }
+    }
+
+    /// <summary>
+    /// A handler for the <see cref="AuthenticationStateProvider.AuthenticationStateChanged"/> event.
+    /// </summary>
+    /// <param name="task">A <see cref="Task"/> that supplies the updated <see cref="AuthenticationState"/>.</param>
+    public delegate void AuthenticationStateChangedHandler(Task<AuthenticationState> task);
+}

src/Components/Components/src/Auth/AuthorizeView.razor

@@ -0,0 +1,68 @@
+@namespace Microsoft.AspNetCore.Components
+
+@if (currentAuthenticationState == null)
+{
+    @Authorizing
+}
+else if (IsAuthorized())
+{
+    @((Authorized ?? ChildContent)?.Invoke(currentAuthenticationState))
+}
+else
+{
+    @NotAuthorized
+}
+
+@functions {
+    private AuthenticationState currentAuthenticationState;
+
+    [CascadingParameter] private Task<AuthenticationState> AuthenticationState { get; set; }
+
+    /// <summary>
+    /// The content that will be displayed if the user is authorized.
+    /// </summary>
+    [Parameter] public RenderFragment<AuthenticationState> ChildContent { get; private set; }
+
+    /// <summary>
+    /// The content that will be displayed if the user is not authorized.
+    /// </summary>
+    [Parameter] public RenderFragment NotAuthorized { get; private set; }
+
+    /// <summary>
+    /// The content that will be displayed if the user is authorized.
+    /// If you specify a value for this parameter, do not also specify a value for <see cref="ChildContent"/>.
+    /// </summary>
+    [Parameter] public RenderFragment<AuthenticationState> Authorized { get; private set; }
+
+    /// <summary>
+    /// The content that will be displayed while asynchronous authorization is in progress.
+    /// </summary>
+    [Parameter] public RenderFragment Authorizing { get; private set; }
+
+    protected override async Task OnParametersSetAsync()
+    {
+        // We allow 'ChildContent' for convenience in basic cases, and 'Authorized' for symmetry
+        // with 'NotAuthorized' in other cases. Besides naming, they are equivalent. To avoid
+        // confusion, explicitly prevent the case where both are supplied.
+        if (ChildContent != null && Authorized != null)
+        {
+            throw new InvalidOperationException($"When using {nameof(AuthorizeView)}, do not specify both '{nameof(Authorized)}' and '{nameof(ChildContent)}'.");
+        }
+
+        // First render in pending state
+        // If the task has already completed, this render will be skipped
+        currentAuthenticationState = null;
+
+        // Then render in completed state
+        currentAuthenticationState = await AuthenticationState;
+    }
+
+    private bool IsAuthorized()
+    {
+        // TODO: Support various authorization condition parameters, equivalent to those offered
+        // by the [Authorize] attribute, e.g., "Roles" and "Policy". This is on hold until we're
+        // able to reference the policy evaluator APIs from this package.
+
+        return currentAuthenticationState.User?.Identity?.IsAuthenticated == true;
+    }
+}

src/Components/Components/src/Auth/CascadingAuthenticationState.razor

@@ -0,0 +1,36 @@
+@namespace Microsoft.AspNetCore.Components
+@implements IDisposable
+@inject AuthenticationStateProvider AuthenticationStateProvider
+
+<CascadingValue T="Task<AuthenticationState>" Value="@_currentAuthenticationStateTask" ChildContent="@ChildContent" />
+
+@functions {
+    private Task<AuthenticationState> _currentAuthenticationStateTask;
+
+    /// <summary>
+    /// The content to which the authentication state should be provided.
+    /// </summary>
+    [Parameter] public RenderFragment ChildContent { get; private set; }
+
+    protected override void OnInit()
+    {
+        AuthenticationStateProvider.AuthenticationStateChanged += OnAuthenticationStateChanged;
+
+        _currentAuthenticationStateTask = AuthenticationStateProvider
+            .GetAuthenticationStateAsync();
+    }
+
+    private void OnAuthenticationStateChanged(Task<AuthenticationState> newAuthStateTask)
+    {
+        Invoke(() =>
+        {
+            _currentAuthenticationStateTask = newAuthStateTask;
+            StateHasChanged();
+        });
+    }
+
+    void IDisposable.Dispose()
+    {
+        AuthenticationStateProvider.AuthenticationStateChanged -= OnAuthenticationStateChanged;
+    }
+}

src/Components/Components/src/ChangeDetection.cs

@@ -40,6 +40,7 @@ private static bool IsKnownImmutableType(Type type)
             => type.IsPrimitive
             || type == typeof(string)
             || type == typeof(DateTime)
+            || type == typeof(Type)
             || type == typeof(decimal);
     }
 }

src/Components/Components/src/Microsoft.AspNetCore.Components.csproj

@@ -1,11 +1,12 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk.Razor">
 
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
     <Description>Components feature for ASP.NET Core.</Description>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <IsShippingPackage>true</IsShippingPackage>
     <IsAspNetCoreApp>true</IsAspNetCoreApp>
+    <RazorLangVersion>3.0</RazorLangVersion>
   </PropertyGroup>
 
   <ItemGroup>