Docs: Add line highlight for markdown

modules/docs/src/Volo.Docs.Web/Markdown/Extensions/CustomCodeBlockExtension.cs

@@ -0,0 +1,34 @@
+using System;
+using Markdig;
+using Markdig.Renderers;
+using Markdig.Renderers.Html;
+using Volo.Docs.Markdown.Renderers;
+
+namespace Volo.Docs.Markdown.Extensions
+{
+    public class CustomCodeBlockExtension : IMarkdownExtension
+    {
+        public void Setup(MarkdownPipelineBuilder pipeline)
+        {
+        }
+
+        public void Setup(MarkdownPipeline pipeline, IMarkdownRenderer renderer)
+        {
+            if (renderer == null)
+            {
+                throw new ArgumentNullException(nameof(renderer));
+            }
+
+            if (renderer is TextRendererBase<HtmlRenderer> htmlRenderer)
+            {
+                var codeBlockRenderer = htmlRenderer.ObjectRenderers.FindExact<CodeBlockRenderer>();
+                if (codeBlockRenderer != null)
+                {
+                    htmlRenderer.ObjectRenderers.Remove(codeBlockRenderer);
+                }
+
+                htmlRenderer.ObjectRenderers.AddIfNotAlready(new CustomCodeBlockRenderer());
+            }
+        }
+    }
+}

modules/docs/src/Volo.Docs.Web/Markdown/Extensions/MarkdownPipelineBuilderExtensions.cs

@@ -0,0 +1,13 @@
+using Markdig;
+
+namespace Volo.Docs.Markdown.Extensions
+{
+    public static class MarkdownPipelineBuilderExtensions
+    {
+        public static MarkdownPipelineBuilder UseCustomCodeBlock(this MarkdownPipelineBuilder pipeline)
+        {
+            pipeline.Extensions.AddIfNotAlready<CustomCodeBlockExtension>();
+            return pipeline;
+        }
+    }
+}

modules/docs/src/Volo.Docs.Web/Markdown/MarkDigMarkdownConverter.cs

@@ -1,6 +1,7 @@
 using System.Text;
 using Markdig;
 using Volo.Abp.DependencyInjection;
+using Volo.Docs.Markdown.Extensions;
 
 namespace Volo.Docs.Markdown
 {
@@ -15,6 +16,7 @@ namespace Volo.Docs.Markdown
               .UseBootstrap()
               .UseGridTables()
               .UsePipeTables()
+              .UseCustomCodeBlock()
               .Build();
         }
 

modules/docs/src/Volo.Docs.Web/Markdown/Renderers/CustomCodeBlockRenderer.cs

@@ -0,0 +1,131 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Text.RegularExpressions;
+using Markdig.Parsers;
+using Markdig.Renderers;
+using Markdig.Renderers.Html;
+using Markdig.Syntax;
+
+namespace Volo.Docs.Markdown.Renderers
+{
+    public class CustomCodeBlockRenderer : HtmlObjectRenderer<CodeBlock>
+    {
+        private const string Pattern = @"\{([^}]+)\}";
+        public bool OutputAttributesOnPre { get; set; }
+
+        public HashSet<string> BlocksAsDiv { get; }
+
+        public CustomCodeBlockRenderer()
+        {
+            BlocksAsDiv = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        }
+        
+        protected override void Write(HtmlRenderer renderer, CodeBlock obj)
+        {
+            renderer.EnsureLine();
+
+            var fencedCodeBlock = obj as FencedCodeBlock;
+            if (fencedCodeBlock?.Info != null && BlocksAsDiv.Contains(fencedCodeBlock.Info))
+            {
+                var infoPrefix = (obj.Parser as FencedCodeBlockParser)?.InfoPrefix ??
+                                 FencedCodeBlockParser.DefaultInfoPrefix;
+
+                if (renderer.EnableHtmlForBlock)
+                {
+                    renderer.Write("<div")
+                        .WriteAttributes(obj.TryGetAttributes(),
+                            cls => cls.StartsWith(infoPrefix, StringComparison.Ordinal) ? cls.Substring(infoPrefix.Length) : cls)
+                        .Write('>');
+                }
+
+                renderer.WriteLeafRawLines(obj, true, true, true);
+
+                if (renderer.EnableHtmlForBlock)
+                {
+                    renderer.WriteLine("</div>");
+                }
+
+            }
+            else
+            {
+                if (renderer.EnableHtmlForBlock)
+                {
+                    renderer.Write("<pre ");
+
+                    if (OutputAttributesOnPre)
+                    {
+                        renderer.WriteAttributes(obj);
+                    }
+                    
+                    var highlightedLines = GetHighlightedLines(fencedCodeBlock);
+                    if (highlightedLines.Any())
+                    {
+                        renderer.WriteAttributes(new HtmlAttributes {Classes = new List<string> {"line-numbers"}});
+
+                        var lines = string.Join(",", highlightedLines);
+                        renderer.Write($"data-line={lines}><code");
+                    }
+                    else
+                    {
+                        renderer.Write("><code");
+                    }
+
+                    if (!OutputAttributesOnPre)
+                    {
+                        renderer.WriteAttributes(obj);
+                    }
+
+                    renderer.Write('>');
+                }
+
+                renderer.WriteLeafRawLines(obj, true, true);
+
+                if (renderer.EnableHtmlForBlock)
+                {
+                    renderer.WriteLine("</code></pre>");
+                }
+            }
+
+            renderer.EnsureLine();
+        }
+
+        private List<int> GetHighlightedLines(FencedCodeBlock fencedCodeBlock)
+        {
+            var highlightedLines = new List<int>();
+
+            if (string.IsNullOrWhiteSpace(fencedCodeBlock?.Arguments))
+            {
+                return highlightedLines;
+            }
+
+            if (Regex.IsMatch(pattern: Pattern, input: fencedCodeBlock.Arguments))
+            {
+                var match = Regex.Match(fencedCodeBlock.Arguments, Pattern);
+                var groups = match.Groups;
+
+                if (groups.Count < 2 || string.IsNullOrWhiteSpace(groups[1].Value))
+                {
+                    return highlightedLines;
+                }
+                
+                var lines = groups[1].Value.Split(",");
+                foreach (var line in lines)
+                {
+                    if (line.Contains("-"))
+                    {
+                        var numbers = line.Split("-");
+                        highlightedLines.AddRange(numbers.Select(number => Convert.ToInt32(number)));
+                    }
+                    else
+                    {
+                        highlightedLines.Add(Convert.ToInt32(line));
+                    }
+                }
+            }
+            
+            return highlightedLines;
+        }
+    }
+}