Enable generic attribute support for wiki markdown containers

osu.Game/Graphics/Containers/Markdown/Extensions/BlockAttributeExtension.cs

@@ -0,0 +1,34 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using Markdig;
+using Markdig.Extensions.GenericAttributes;
+using Markdig.Renderers;
+using Markdig.Syntax;
+
+namespace osu.Game.Graphics.Containers.Markdown.Extensions
+{
+    /// <summary>
+    /// A variant of <see cref="Markdig.Extensions.GenericAttributes.GenericAttributesExtension"/>
+    /// which only handles generic attributes in the current markdown <see cref="Block"/> and ignores inline generic attributes.
+    /// </summary>
+    /// <remarks>
+    /// For rationale, see implementation of <see cref="Setup(Markdig.MarkdownPipelineBuilder)"/>.
+    /// </remarks>
+    public class BlockAttributeExtension : IMarkdownExtension
+    {
+        private readonly GenericAttributesExtension genericAttributesExtension = new GenericAttributesExtension();
+
+        public void Setup(MarkdownPipelineBuilder pipeline)
+        {
+            genericAttributesExtension.Setup(pipeline);
+
+            // GenericAttributesExtension registers a GenericAttributesParser in pipeline.InlineParsers.
+            // this conflicts with the CustomContainerExtension, leading to some custom containers (e.g. flags) not displaying.
+            // as a workaround, remove the inline parser here before it can do damage.
+            pipeline.InlineParsers.RemoveAll(parser => parser is GenericAttributesParser);
+        }
+
+        public void Setup(MarkdownPipeline pipeline, IMarkdownRenderer renderer) => genericAttributesExtension.Setup(pipeline, renderer);
+    }
+}

osu.Game/Graphics/Containers/Markdown/Extensions/OsuMarkdownExtensions.cs

@@ -0,0 +1,21 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using Markdig;
+
+namespace osu.Game.Graphics.Containers.Markdown.Extensions
+{
+    public static class OsuMarkdownExtensions
+    {
+        /// <summary>
+        /// Uses the block attributes extension.
+        /// </summary>
+        /// <param name="pipeline">The pipeline.</param>
+        /// <returns>The modified pipeline.</returns>
+        public static MarkdownPipelineBuilder UseBlockAttributes(this MarkdownPipelineBuilder pipeline)
+        {
+            pipeline.Extensions.AddIfNotAlready<BlockAttributeExtension>();
+            return pipeline;
+        }
+    }
+}

osu.Game/Graphics/Containers/Markdown/OsuMarkdownContainerOptions.cs

@@ -6,6 +6,7 @@ using Markdig.Extensions.AutoLinks;
 using Markdig.Extensions.CustomContainers;
 using Markdig.Extensions.EmphasisExtras;
 using Markdig.Extensions.Footnotes;
+using osu.Game.Graphics.Containers.Markdown.Extensions;
 
 namespace osu.Game.Graphics.Containers.Markdown
 {
@@ -32,6 +33,12 @@ namespace osu.Game.Graphics.Containers.Markdown
         /// <seealso cref="CustomContainerExtension"/>
         public bool CustomContainers { get; init; }
 
+        /// <summary>
+        /// Allows the <see cref="OsuMarkdownContainer"/> to parse custom attributes in block elements (used e.g. for custom anchor names in the wiki).
+        /// </summary>
+        /// <seealso cref="BlockAttributeExtension"/>
+        public bool BlockAttributes { get; init; }
+
         /// <summary>
         /// Returns a prepared <see cref="MarkdownPipeline"/> according to the options specified by the current <see cref="OsuMarkdownContainerOptions"/> instance.
         /// </summary>
@@ -53,7 +60,10 @@ namespace osu.Game.Graphics.Containers.Markdown
                 pipeline = pipeline.UseAutoLinks();
 
             if (CustomContainers)
-                pipeline.UseCustomContainers();
+                pipeline = pipeline.UseCustomContainers();
+
+            if (BlockAttributes)
+                pipeline = pipeline.UseBlockAttributes();
 
             return pipeline.Build();
         }

osu.Game/Overlays/Wiki/Markdown/WikiMarkdownContainer.cs

@@ -19,7 +19,8 @@ namespace osu.Game.Overlays.Wiki.Markdown
         protected override OsuMarkdownContainerOptions Options => new OsuMarkdownContainerOptions
         {
             Footnotes = true,
-            CustomContainers = true
+            CustomContainers = true,
+            BlockAttributes = true
         };
 
         public string CurrentPath