Split AuthorizeView in two, so "Core" part can be reused from routing

Author: SteveSandersonMS

src/Components/Components/src/Auth/AuthorizeView.cs

@@ -0,0 +1,40 @@
+// 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 Microsoft.AspNetCore.Authorization;
+
+namespace Microsoft.AspNetCore.Components
+{
+#pragma warning disable PUB0001 // Pubternal type in public API
+    /// <summary>
+    /// Displays differing content depending on the user's authorization status.
+    /// </summary>
+    public class AuthorizeView : Internal.AuthorizeViewCore
+#pragma warning restore PUB0001 // Pubternal type in public API
+    {
+        private readonly IAuthorizeData[] selfAsAuthorizeData;
+
+        /// <summary>
+        /// Constructs an instance of <see cref="AuthorizeView"/>.
+        /// </summary>
+        public AuthorizeView()
+        {
+            selfAsAuthorizeData = new[] { new AuthorizeDataAdapter(this) };
+        }
+
+        /// <summary>
+        /// The policy name that determines whether the content can be displayed.
+        /// </summary>
+        [Parameter] public string Policy { get; private set; }
+
+        /// <summary>
+        /// A comma delimited list of roles that are allowed to display the content.
+        /// </summary>
+        [Parameter] public string Roles { get; private set; }
+
+        /// <summary>
+        /// Gets the data used for authorization.
+        /// </summary>
+        protected override IAuthorizeData[] AuthorizeData => selfAsAuthorizeData;
+    }
+}

src/Components/Components/src/Auth/AuthorizeView.razor renamed to src/Components/Components/src/Auth/AuthorizeViewCore.razor

@@ -1,4 +1,8 @@
-@namespace Microsoft.AspNetCore.Components
+@*
+    Ideally, this would be an internal (and probably abstract) class. So temporarily
+    this is in an "internal" namespace and should become actually internal in the future.
+*@
+@namespace Microsoft.AspNetCore.Components.Internal
 @using System.Security.Claims
 @using Microsoft.AspNetCore.Authorization
 @inject IAuthorizationService AuthorizationService
@@ -18,7 +22,6 @@ else
 }
 
 @functions {
-    private IAuthorizeData[] selfAsAuthorizeData;
     private AuthenticationState currentAuthenticationState;
     private bool isAuthorized;
 
@@ -45,29 +48,11 @@ else
     /// </summary>
     [Parameter] public RenderFragment Authorizing { get; private set; }
 
-    /// <summary>
-    /// The policy name that determines whether the content can be displayed.
-    /// </summary>
-    [Parameter] public string Policy { get; private set; }
-
-    /// <summary>
-    /// A comma delimited list of roles that are allowed to display the content.
-    /// </summary>
-    [Parameter] public string Roles { get; private set; }
-
     /// <summary>
     /// The resource to which access is being controlled.
     /// </summary>
     [Parameter] public object Resource { get; private set; }
 
-    protected override void OnInit()
-    {
-        selfAsAuthorizeData = new[]
-        {
-            new AuthorizeDataAdapter((AuthorizeView)(object)this)
-        };
-    }
-
     protected override async Task OnParametersSetAsync()
     {
         // We allow 'ChildContent' for convenience in basic cases, and 'Authorized' for symmetry
@@ -89,10 +74,16 @@ else
         isAuthorized = await IsAuthorizedAsync(currentAuthenticationState.User);
     }
 
+    // TODO: Make abstract instead
+    protected virtual IAuthorizeData[] AuthorizeData
+    {
+        get => throw new NotImplementedException($"{nameof(AuthorizeData)} must be overridden and supplied by a derived class.");
+    }
+
     private async Task<bool> IsAuthorizedAsync(ClaimsPrincipal user)
     {
         var policy = await AuthorizationPolicy.CombineAsync(
-            AuthorizationPolicyProvider, selfAsAuthorizeData);
+            AuthorizationPolicyProvider, AuthorizeData);
         var result = await AuthorizationService.AuthorizeAsync(user, Resource, policy);
         return result.Succeeded;
     }