Website Rendering: Add configurable output caching for template rendered pages

src/Umbraco.Core/Cache/IWebsiteOutputCacheDurationProvider.cs

@@ -0,0 +1,23 @@
+using Umbraco.Cms.Core.Models.PublishedContent;
+
+namespace Umbraco.Cms.Core.Cache;
+
+/// <summary>
+///     Provides custom cache durations per content item for website output caching.
+/// </summary>
+/// <remarks>
+///     A single registration of this interface is expected.
+///     The default implementation can be replaced to vary duration by content type, path, or content properties.
+/// </remarks>
+public interface IWebsiteOutputCacheDurationProvider
+{
+    /// <summary>
+    ///     Returns a custom cache duration for the given content, or <c>null</c> to use the configured default.
+    /// </summary>
+    /// <param name="content">The published content being cached.</param>
+    /// <returns>
+    ///     A custom cache duration, <see cref="TimeSpan.Zero"/> to disable caching for this content,
+    ///     or <c>null</c> to use the configured default duration.
+    /// </returns>
+    TimeSpan? GetDuration(IPublishedContent content);
+}

src/Umbraco.Core/Cache/IWebsiteOutputCacheEvictionProvider.cs

@@ -0,0 +1,26 @@
+namespace Umbraco.Cms.Core.Cache;
+
+/// <summary>
+///     Provides additional cache tags to evict when content changes.
+/// </summary>
+/// <remarks>
+///     <para>
+///         Multiple implementations can be registered. The eviction handler iterates all providers
+///         to collect additional tags to evict beyond the built-in content key tag.
+///     </para>
+///     <para>
+///         Works as a pair with <see cref="IWebsiteOutputCacheTagProvider"/>: the tag provider adds
+///         custom tags when caching a response, and this provider maps content changes back to those
+///         tags at eviction time.
+///     </para>
+/// </remarks>
+public interface IWebsiteOutputCacheEvictionProvider
+{
+    /// <summary>
+    ///     Returns additional cache tags to evict when the specified content changes.
+    /// </summary>
+    /// <param name="context">Details of the content change.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    /// <returns>Additional cache tags to evict.</returns>
+    Task<IEnumerable<string>> GetAdditionalEvictionTagsAsync(OutputCacheContentChangedContext context, CancellationToken cancellationToken = default);
+}

src/Umbraco.Core/Cache/IWebsiteOutputCacheManager.cs

@@ -0,0 +1,31 @@
+namespace Umbraco.Cms.Core.Cache;
+
+/// <summary>
+///     Provides programmatic eviction of website output cache entries.
+/// </summary>
+/// <remarks>
+///     Use this to evict cached pages from custom code, for example when external data changes
+///     that affects a rendered page. All methods are no-ops when output caching is not enabled.
+/// </remarks>
+public interface IWebsiteOutputCacheManager
+{
+    /// <summary>
+    ///     Evicts the cached page for a specific content item.
+    /// </summary>
+    /// <param name="contentKey">The key of the content item to evict.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    Task EvictContentAsync(Guid contentKey, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    ///     Evicts all cached pages matching a custom tag.
+    /// </summary>
+    /// <param name="tag">The cache tag to evict.</param>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    Task EvictByTagAsync(string tag, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    ///     Evicts all cached website pages.
+    /// </summary>
+    /// <param name="cancellationToken">A cancellation token.</param>
+    Task EvictAllAsync(CancellationToken cancellationToken = default);
+}

src/Umbraco.Core/Cache/IWebsiteOutputCacheTagProvider.cs

@@ -0,0 +1,22 @@
+using Umbraco.Cms.Core.Models.PublishedContent;
+
+namespace Umbraco.Cms.Core.Cache;
+
+/// <summary>
+///     Provides additional cache tags when caching a website content page.
+/// </summary>
+/// <remarks>
+///     Multiple implementations can be registered; the output cache policy iterates all of them
+///     to collect tags at cache-write time. Works as a pair with <see cref="IWebsiteOutputCacheEvictionProvider"/>:
+///     the tag provider adds custom tags when caching, and the eviction provider maps content changes
+///     back to those tags at eviction time.
+/// </remarks>
+public interface IWebsiteOutputCacheTagProvider
+{
+    /// <summary>
+    ///     Returns additional cache tags for the given published content.
+    /// </summary>
+    /// <param name="content">The published content being cached.</param>
+    /// <returns>Additional cache tags to associate with the cached response.</returns>
+    IEnumerable<string> GetTags(IPublishedContent content);
+}

src/Umbraco.Core/Cache/OutputCacheContentChangedContext.cs

@@ -0,0 +1,42 @@
+namespace Umbraco.Cms.Core.Cache;
+
+/// <summary>
+///     Describes a content change that triggered output cache eviction.
+/// </summary>
+public class OutputCacheContentChangedContext
+{
+    /// <summary>
+    ///     Initializes a new instance of the <see cref="OutputCacheContentChangedContext"/> class.
+    /// </summary>
+    /// <param name="contentId">The integer ID of the content that changed.</param>
+    /// <param name="contentKey">The key of the content that changed.</param>
+    /// <param name="publishedCultures">The cultures that were published, if applicable.</param>
+    /// <param name="unpublishedCultures">The cultures that were unpublished, if applicable.</param>
+    public OutputCacheContentChangedContext(int contentId, Guid contentKey, IReadOnlyCollection<string> publishedCultures, IReadOnlyCollection<string> unpublishedCultures)
+    {
+        ContentId = contentId;
+        ContentKey = contentKey;
+        PublishedCultures = publishedCultures;
+        UnpublishedCultures = unpublishedCultures;
+    }
+
+    /// <summary>
+    ///     Gets the integer ID of the content that changed.
+    /// </summary>
+    public int ContentId { get; }
+
+    /// <summary>
+    ///     Gets the key of the content that changed.
+    /// </summary>
+    public Guid ContentKey { get; }
+
+    /// <summary>
+    ///     Gets the cultures that were published, if applicable. Empty for invariant content.
+    /// </summary>
+    public IReadOnlyCollection<string> PublishedCultures { get; }
+
+    /// <summary>
+    ///     Gets the cultures that were unpublished, if applicable. Empty for invariant content.
+    /// </summary>
+    public IReadOnlyCollection<string> UnpublishedCultures { get; }
+}

src/Umbraco.Core/Configuration/Models/WebsiteSettings.cs

@@ -0,0 +1,46 @@
+using System.ComponentModel;
+
+namespace Umbraco.Cms.Core.Configuration.Models;
+
+/// <summary>
+///     Typed configuration options for website rendering settings.
+/// </summary>
+[UmbracoOptions(Constants.Configuration.ConfigWebsite)]
+public class WebsiteSettings
+{
+    private const bool StaticEnabled = false;
+
+    /// <summary>
+    ///     Gets or sets the output cache settings for website rendering.
+    /// </summary>
+    public OutputCacheSettings OutputCache { get; set; } = new();
+
+    /// <summary>
+    ///     Typed configuration options for output caching of website rendering.
+    /// </summary>
+    public class OutputCacheSettings
+    {
+        private const string StaticDuration = "00:00:10"; // Ten seconds.
+
+        /// <summary>
+        ///     Gets or sets a value indicating whether website output caching is enabled.
+        /// </summary>
+        /// <value><c>true</c> if website output caching should be enabled; otherwise, <c>false</c>.</value>
+        /// <remarks>
+        ///     The default value is <c>false</c>.
+        /// </remarks>
+        [DefaultValue(StaticEnabled)]
+        public bool Enabled { get; set; } = StaticEnabled;
+
+        /// <summary>
+        ///     Gets or sets the duration for which rendered content pages are cached.
+        /// </summary>
+        /// <value>Cache lifetime.</value>
+        /// <remarks>
+        ///     The default cache duration is ten seconds, if this configuration value is not provided.
+        ///     Can be overridden per content item via <c>IWebsiteOutputCacheDurationProvider</c>.
+        /// </remarks>
+        [DefaultValue(StaticDuration)]
+        public TimeSpan ContentDuration { get; set; } = TimeSpan.Parse(StaticDuration);
+    }
+}

src/Umbraco.Core/Constants-Configuration.cs

@@ -297,6 +297,11 @@ public static class Configuration
         public const string ConfigBackOfficeTokenCookie = ConfigSecurity + ":BackOfficeTokenCookie";
         public const string ConfigDictionary = ConfigPrefix + "Dictionary";
 
+        /// <summary>
+        ///     The configuration key for website settings.
+        /// </summary>
+        public const string ConfigWebsite = ConfigPrefix + "Website";
+
         /// <summary>
         ///     Contains constants for named options used in configuration.
         /// </summary>

src/Umbraco.Core/Constants-Website.cs

@@ -0,0 +1,41 @@
+namespace Umbraco.Cms.Core;
+
+public static partial class Constants
+{
+    /// <summary>
+    ///     Constants related to the website rendering pipeline.
+    /// </summary>
+    public static class Website
+    {
+        /// <summary>
+        ///     Constants related to website output caching.
+        /// </summary>
+        public static class OutputCache
+        {
+            /// <summary>
+            ///     The named output cache policy for Umbraco website content.
+            /// </summary>
+            public const string ContentCachePolicy = "UmbracoWebsiteContent";
+
+            /// <summary>
+            ///     Tag prefix for a specific content item (followed by the content key).
+            /// </summary>
+            public const string ContentTagPrefix = "umb-content-";
+
+            /// <summary>
+            ///     Tag prefix for ancestor-based eviction (followed by the ancestor content key).
+            /// </summary>
+            public const string AncestorTagPrefix = "umb-content-ancestor-";
+
+            /// <summary>
+            ///     Tag prefix for content type-based eviction (followed by the content type alias).
+            /// </summary>
+            public const string ContentTypeTagPrefix = "umb-content-type-";
+
+            /// <summary>
+            ///     Tag that matches all cached website content pages.
+            /// </summary>
+            public const string AllContentTag = "umb-content-all";
+        }
+    }
+}

src/Umbraco.Core/DependencyInjection/UmbracoBuilder.Configuration.cs

@@ -102,7 +102,8 @@
             .AddUmbracoOptions<CacheSettings>()
             .AddUmbracoOptions<SystemDateMigrationSettings>()
             .AddUmbracoOptions<DistributedJobSettings>()
-            .AddUmbracoOptions<BackOfficeTokenCookieSettings>();
+            .AddUmbracoOptions<BackOfficeTokenCookieSettings>()
+            .AddUmbracoOptions<WebsiteSettings>();
 
         // Configure connection string and ensure it's updated when the configuration changes
         builder.Services.AddSingleton<IConfigureOptions<ConnectionStrings>, ConfigureConnectionStrings>();

src/Umbraco.Web.Common/Controllers/RenderController.cs

@@ -1,6 +1,7 @@
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.Filters;
 using Microsoft.AspNetCore.Mvc.ViewEngines;
+using Microsoft.AspNetCore.OutputCaching;
 using Microsoft.Extensions.Logging;
 using Umbraco.Cms.Core.Models;
 using Umbraco.Cms.Core.Routing;
@@ -47,6 +48,7 @@ protected IUmbracoContext UmbracoContext
     /// <summary>
     ///     The default action to render the front-end view.
     /// </summary>
+    [OutputCache(PolicyName = Cms.Core.Constants.Website.OutputCache.ContentCachePolicy)]
     public virtual IActionResult Index() => CurrentTemplate(new ContentModel(CurrentPage));
 
     /// <summary>

src/Umbraco.Web.Website/Caching/ContentTypeOutputCacheTagProvider.cs

@@ -0,0 +1,17 @@
+using Umbraco.Cms.Core;
+using Umbraco.Cms.Core.Cache;
+using Umbraco.Cms.Core.Models.PublishedContent;
+
+namespace Umbraco.Cms.Web.Website.Caching;
+
+/// <summary>
+///     Tags cached pages with their content type alias, enabling eviction by content type.
+/// </summary>
+internal sealed class ContentTypeOutputCacheTagProvider : IWebsiteOutputCacheTagProvider
+{
+    /// <inheritdoc />
+    public IEnumerable<string> GetTags(IPublishedContent content)
+    {
+        yield return Constants.Website.OutputCache.ContentTypeTagPrefix + content.ContentType.Alias;
+    }
+}

src/Umbraco.Web.Website/Caching/DefaultWebsiteOutputCacheDurationProvider.cs

@@ -0,0 +1,14 @@
+using Umbraco.Cms.Core.Cache;
+using Umbraco.Cms.Core.Models.PublishedContent;
+
+namespace Umbraco.Cms.Web.Website.Caching;
+
+/// <summary>
+///     Default implementation of <see cref="IWebsiteOutputCacheDurationProvider"/> that always returns <c>null</c>,
+///     deferring to the configured <c>ContentDuration</c> for all content.
+/// </summary>
+internal sealed class DefaultWebsiteOutputCacheDurationProvider : IWebsiteOutputCacheDurationProvider
+{
+    /// <inheritdoc />
+    public TimeSpan? GetDuration(IPublishedContent content) => null;
+}

src/Umbraco.Web.Website/Caching/DefaultWebsiteOutputCacheRequestFilter.cs

@@ -0,0 +1,40 @@
+using Microsoft.AspNetCore.Http;
+using Umbraco.Cms.Core.Models.PublishedContent;
+using Umbraco.Cms.Core.Web;
+
+namespace Umbraco.Cms.Web.Website.Caching;
+
+/// <summary>
+///     Default implementation of <see cref="IWebsiteOutputCacheRequestFilter"/> that prevents caching
+///     for preview mode and authenticated member requests.
+/// </summary>
+public class DefaultWebsiteOutputCacheRequestFilter : IWebsiteOutputCacheRequestFilter
+{
+    private readonly IUmbracoContextAccessor _umbracoContextAccessor;
+
+    /// <summary>
+    ///     Initializes a new instance of the <see cref="DefaultWebsiteOutputCacheRequestFilter"/> class.
+    /// </summary>
+    /// <param name="umbracoContextAccessor">The Umbraco context accessor.</param>
+    public DefaultWebsiteOutputCacheRequestFilter(IUmbracoContextAccessor umbracoContextAccessor)
+        => _umbracoContextAccessor = umbracoContextAccessor;
+
+    /// <inheritdoc />
+    public virtual bool IsCacheable(HttpContext context, IPublishedContent content)
+        => ShouldExcludePreview() is false && ShouldExcludeAuthenticated(context) is false;
+
+    /// <summary>
+    ///     Gets a value indicating whether preview mode requests should be excluded from caching.
+    ///     By default returns <c>true</c> when the current request is in Umbraco preview mode.
+    /// </summary>
+    protected virtual bool ShouldExcludePreview()
+        => _umbracoContextAccessor.TryGetUmbracoContext(out IUmbracoContext? umbracoContext)
+           && umbracoContext.InPreviewMode;
+
+    /// <summary>
+    ///     Gets a value indicating whether authenticated requests should be excluded from caching.
+    ///     By default returns <c>true</c> when the current request is from an authenticated user.
+    /// </summary>
+    protected virtual bool ShouldExcludeAuthenticated(HttpContext context)
+        => context.User.Identity?.IsAuthenticated == true;
+}