CacheBoundary support for Blazor

src/Components/Authorization/src/AuthorizeViewCore.cs

@@ -10,6 +10,7 @@ namespace Microsoft.AspNetCore.Components.Authorization;
 /// <summary>
 /// A base class for components that display differing content depending on the user's authorization status.
 /// </summary>
+[CacheBoundaryPolicy(Excluded = true, VaryBy = CacheBoundaryVaryBy.User)]
 public abstract class AuthorizeViewCore : ComponentBase
 {
     private AuthenticationState? currentAuthenticationState;

src/Components/Components/src/CacheBoundaryPolicyAttribute.cs

@@ -0,0 +1,29 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.AspNetCore.Components;
+
+/// <summary>
+/// Specifies how a component interacts with an enclosing CacheBoundary.
+/// When <see cref="Excluded"/> is <see langword="true"/>, the component's subtree becomes
+/// a "hole" in the cached output and is re-rendered on every request.
+/// Optionally, set <see cref="VaryBy"/> to lift the exclusion when the cache boundary
+/// varies by the specified dimensions.
+/// </summary>
+[AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = true)]
+public sealed class CacheBoundaryPolicyAttribute : Attribute
+{
+    /// <summary>
+    /// Gets or sets a value indicating whether the component should be excluded
+    /// from cached output. Defaults to <see langword="false"/>.
+    /// </summary>
+    public bool Excluded { get; set; }
+
+    /// <summary>
+    /// Gets or sets the vary-by dimensions that, when active on the enclosing
+    /// CacheBoundary, lift the exclusion. The component is only excluded when
+    /// the cache boundary does <em>not</em> vary by all specified dimensions.
+    /// Defaults to <see cref="CacheBoundaryVaryBy.None"/>.
+    /// </summary>
+    public CacheBoundaryVaryBy VaryBy { get; set; }
+}

src/Components/Components/src/CacheBoundaryVaryBy.cs

@@ -0,0 +1,48 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.AspNetCore.Components;
+
+/// <summary>
+/// Describes which vary-by dimensions are active on an enclosing CacheBoundary.
+/// Used as flags in <see cref="CacheBoundaryPolicyAttribute"/> to express conditional
+/// cache exclusion, and internally to communicate the active dimensions to the renderer.
+/// </summary>
+[Flags]
+public enum CacheBoundaryVaryBy
+{
+    /// <summary>
+    /// No vary-by dimensions.
+    /// </summary>
+    None = 0,
+
+    /// <summary>
+    /// Vary by query string parameters.
+    /// </summary>
+    Query = 1 << 0,
+
+    /// <summary>
+    /// Vary by route parameters.
+    /// </summary>
+    Route = 1 << 1,
+
+    /// <summary>
+    /// Vary by HTTP header values.
+    /// </summary>
+    Header = 1 << 2,
+
+    /// <summary>
+    /// Vary by cookie values.
+    /// </summary>
+    Cookie = 1 << 3,
+
+    /// <summary>
+    /// Vary by the authenticated user.
+    /// </summary>
+    User = 1 << 4,
+
+    /// <summary>
+    /// Vary by culture.
+    /// </summary>
+    Culture = 1 << 5,
+}

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

@@ -15,6 +15,7 @@
 
   <ItemGroup>
     <Compile Include="$(ComponentsSharedSourceRoot)src\ArrayBuilder.cs" LinkBase="RenderTree" />
+    <Compile Include="$(ComponentsSharedSourceRoot)src\ComponentKeyHelper.cs" LinkBase="Shared" />
     <Compile Include="$(ComponentsSharedSourceRoot)src\JsonSerializerOptionsProvider.cs" />
     <Compile Include="$(ComponentsSharedSourceRoot)src\HotReloadManager.cs" LinkBase="HotReload" />
     <Compile Include="$(ComponentsSharedSourceRoot)src\RootTypeCache.cs" LinkBase="Shared" />

src/Components/Components/src/PersistentState/PersistentStateValueProviderKeyResolver.cs

@@ -126,17 +126,8 @@ private static string ComputeFinalKey(byte[] preKey, ComponentState componentSta
 
     private static ReadOnlySpan<char> ResolveKeySpan(object? key)
     {
-        if (key is IFormattable formattable)
-        {
-            var keyString = formattable.ToString("", CultureInfo.InvariantCulture);
-            return keyString.AsSpan();
-        }
-        else if (key is IConvertible convertible)
-        {
-            var keyString = convertible.ToString(CultureInfo.InvariantCulture);
-            return keyString.AsSpan();
-        }
-        return default;
+        var formatted = ComponentKeyHelper.FormatSerializableKey(key);
+        return formatted.AsSpan();
     }
 
     private static void GrowBuffer(ref byte[]? pool, ref Span<byte> keyBuffer, int? size = null)
@@ -154,7 +145,7 @@ private static void GrowBuffer(ref byte[]? pool, ref Span<byte> keyBuffer, int?
     private static object? GetSerializableKey(ComponentState componentState)
     {
         var componentKey = componentState.GetComponentKey();
-        if (componentKey != null && IsSerializableKey(componentKey))
+        if (componentKey != null && ComponentKeyHelper.IsSerializableKey(componentKey))
         {
             return componentKey;
         }
@@ -195,20 +186,4 @@ private static string GetParentComponentType(ComponentState componentState)
 
     private static byte[] KeyFactory((string parentComponentType, string componentType, string propertyName) parts) =>
         SHA256.HashData(Encoding.UTF8.GetBytes(string.Join(".", parts.parentComponentType, parts.componentType, parts.propertyName)));
-
-    private static bool IsSerializableKey(object key)
-    {
-        if (key == null)
-        {
-            return false;
-        }
-        var keyType = key.GetType();
-        var result = Type.GetTypeCode(keyType) != TypeCode.Object
-            || keyType == typeof(Guid)
-            || keyType == typeof(DateTimeOffset)
-            || keyType == typeof(DateOnly)
-            || keyType == typeof(TimeOnly);
-
-        return result;
-    }
 }

src/Components/Components/src/PublicAPI.Unshipped.txt

@@ -1,4 +1,18 @@
 #nullable enable
+Microsoft.AspNetCore.Components.CacheBoundaryPolicyAttribute
+Microsoft.AspNetCore.Components.CacheBoundaryPolicyAttribute.CacheBoundaryPolicyAttribute() -> void
+Microsoft.AspNetCore.Components.CacheBoundaryPolicyAttribute.Excluded.get -> bool
+Microsoft.AspNetCore.Components.CacheBoundaryPolicyAttribute.Excluded.set -> void
+Microsoft.AspNetCore.Components.CacheBoundaryPolicyAttribute.VaryBy.get -> Microsoft.AspNetCore.Components.CacheBoundaryVaryBy
+Microsoft.AspNetCore.Components.CacheBoundaryPolicyAttribute.VaryBy.set -> void
+Microsoft.AspNetCore.Components.CacheBoundaryVaryBy
+Microsoft.AspNetCore.Components.CacheBoundaryVaryBy.Cookie = 8 -> Microsoft.AspNetCore.Components.CacheBoundaryVaryBy
+Microsoft.AspNetCore.Components.CacheBoundaryVaryBy.Culture = 32 -> Microsoft.AspNetCore.Components.CacheBoundaryVaryBy
+Microsoft.AspNetCore.Components.CacheBoundaryVaryBy.Header = 4 -> Microsoft.AspNetCore.Components.CacheBoundaryVaryBy
+Microsoft.AspNetCore.Components.CacheBoundaryVaryBy.None = 0 -> Microsoft.AspNetCore.Components.CacheBoundaryVaryBy
+Microsoft.AspNetCore.Components.CacheBoundaryVaryBy.Query = 1 -> Microsoft.AspNetCore.Components.CacheBoundaryVaryBy
+Microsoft.AspNetCore.Components.CacheBoundaryVaryBy.Route = 2 -> Microsoft.AspNetCore.Components.CacheBoundaryVaryBy
+Microsoft.AspNetCore.Components.CacheBoundaryVaryBy.User = 16 -> Microsoft.AspNetCore.Components.CacheBoundaryVaryBy
 abstract Microsoft.AspNetCore.Components.CascadingParameterSubscription.Dispose() -> void
 abstract Microsoft.AspNetCore.Components.CascadingParameterSubscription.GetCurrentValue() -> object?
 Microsoft.AspNetCore.Components.CascadingParameterSubscription

src/Components/Components/src/Sections/SectionContent.cs

@@ -6,6 +6,7 @@ namespace Microsoft.AspNetCore.Components.Sections;
 /// <summary>
 /// Provides content to <see cref="SectionOutlet"/> components with matching <see cref="SectionId"/>s.
 /// </summary>
+[CacheBoundaryPolicy(Excluded = true)]
 public sealed class SectionContent : IComponent, IDisposable
 {
     private object? _registeredIdentifier;

src/Components/Components/src/Sections/SectionOutlet.cs

@@ -8,6 +8,7 @@ namespace Microsoft.AspNetCore.Components.Sections;
 /// <summary>
 /// Renders content provided by <see cref="SectionContent"/> components with matching <see cref="SectionId"/>s.
 /// </summary>
+[CacheBoundaryPolicy(Excluded = true)]
 public sealed class SectionOutlet : IComponent, IDisposable
 {
     private static readonly RenderFragment _emptyRenderFragment = _ => { };