Added original repo

action.yml

@@ -11,7 +11,7 @@ inputs:
 
   docfx-version:
     description: ''
-    default: '2.66.1'
+    default: '2.74.1'
 
   newtonsoftjson-version:
     description: ''
@@ -26,10 +26,10 @@ runs:
         submodules: recursive
         fetch-depth: 0
 
-    - name: Setup .NET 7
+    - name: Setup .NET 8
       uses: actions/setup-dotnet@master
       with:
-        dotnet-version: 7.x.x
+        dotnet-version: 8.x.x
 
     - name: Setup BUTR GPR
       uses: actions/setup-dotnet@master
@@ -47,28 +47,28 @@ runs:
       shell: pwsh
 
     - name: Build DocFx.Plugin.LastModified
-      run: dotnet build ${{ github.action_path }}/build/DocFx.Plugin.LastModified --configuration Release --output ${{inputs.docs-directory}}/_template/last-modified/plugins;
+      run: dotnet publish ${{ github.action_path }}/build/DocFx.Plugin.LastModified --configuration Release --output ${{inputs.docs-directory}}/_template/last-modified/plugins;
       shell: pwsh
 
 # When a custom fork is needed
-    - uses: actions/checkout@v3
+#    - uses: actions/checkout@v3
-      with:
+#      with:
-        repository: BUTR/docfx
+#        repository: BUTR/docfx
-        path: _actions_docfx
+#        path: _actions_docfx
-    - uses: actions/setup-node@v3
+#    - uses: actions/setup-node@v4
-      with:
+#      with:
-        node-version: 16
+#        node-version: 16
-    - run: npm install
+#    - run: npm install
-      working-directory: _actions_docfx/templates
+#      working-directory: _actions_docfx/templates
-      shell: pwsh
+#      shell: pwsh
-    - run: npm run build
+#    - run: npm run build
-      working-directory: _actions_docfx/templates
+#      working-directory: _actions_docfx/templates
-      shell: pwsh
+#      shell: pwsh
-    - run: dotnet pack _actions_docfx/src/docfx -c Release -o _actions_docfx/drop/nuget
+#    - run: dotnet pack _actions_docfx/src/docfx -c Release -o _actions_docfx/drop/nuget
-      shell: pwsh
-    - run: dotnet tool update --global docfx
-      working-directory: _actions_docfx
-      shell: pwsh
-#    - name: Install DocFX
-#      run: dotnet tool update -g docfx
 #      shell: pwsh
+#    - run: dotnet tool update --global docfx
+#      working-directory: _actions_docfx
+#      shell: pwsh
+    - name: Install DocFX
+      run: dotnet tool update -g docfx
+      shell: pwsh

build/DocFx.Plugin.LastModified/CommitDataType.cs

@@ -1,8 +0,0 @@
-namespace DocFx.Plugin.LastModified
-{
-    public enum CommitDataType
-    {
-        Date,
-        Body
-    }
-}

build/DocFx.Plugin.LastModified/DocFx.Plugin.LastModified.csproj

@@ -1,10 +1,10 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <AssemblyName>LastModifiedPostProcessor</AssemblyName>
     <RootNamespace>DocFx.Plugin.LastModified</RootNamespace>
-    <Version>1.2.4</Version>
+    <Version>1.2.5</Version>
     <RepositoryUrl>https://github.com/Still34/DocFx.Plugin.LastModified</RepositoryUrl>
     <PackageLicenseUrl>https://github.com/Still34/DocFx.Plugin.LastModified/blob/master/LICENSE</PackageLicenseUrl>
     <RepositoryType>GitHub</RepositoryType>
@@ -15,14 +15,16 @@
     <Authors>Still Hsu</Authors>
     <Product />
     <PackageVersion>1.2.5</PackageVersion>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="htmlagilitypack" Version="1.11.46" />
+    <PackageReference Include="Docfx.Common" Version="2.74.1" />
-    <PackageReference Include="libgit2sharp" Version="0.27.2" />
+    <PackageReference Include="Docfx.Plugins" Version="2.74.1" />
+    <PackageReference Include="htmlagilitypack" Version="1.11.54" />
+    <PackageReference Include="libgit2sharp" Version="0.29.0" />
     <PackageReference Include="Microsoft.Composition" Version="1.0.31" />
-    <PackageReference Include="Microsoft.DocAsCode.Common" Version="2.66.1" />
+    <PackageReference Include="YamlDotNet" Version="13.7.1" />
-    <PackageReference Include="Microsoft.DocAsCode.Plugins" Version="2.66.1" />
   </ItemGroup>
 
 </Project>

build/DocFx.Plugin.LastModified/Files/YamlManagedReference.cs

@@ -0,0 +1,45 @@
+namespace DocFx.Plugin.LastModified.Files;
+
+/// <summary>
+/// A managed reference YAML document.
+/// </summary>
+public class ManagedReferenceDocument
+{
+    public required ManagedReferenceItem[]? Items { get; set; }
+
+    public class ManagedReferenceItem
+    {
+        public required string Uid { get; set; }
+
+        public required string CommentId { get; set; }
+
+        public required string Id { get; set; }
+
+        public required string Name { get; set; }
+
+        public required string FullName { get; set; }
+
+        public required string NameWithType { get; set; }
+
+        public string? Type { get; set; }
+
+        public string? Parent { get; set; }
+
+        public string[]? Children { get; set; }
+
+        public string[]? Langs { get; set; }
+
+        public ManagedReferenceItemSource? Source { get; set; }
+
+        public string[]? Assemblies { get; set; }
+    }
+
+    public class ManagedReferenceItemSource
+    {
+        public required string Id { get; set; }
+
+        public required string Path { get; set; }
+
+        public int? StartLine { get; set; }
+    }
+}

build/DocFx.Plugin.LastModified/Helpers/RepositoryHelper.cs

@@ -1,47 +1,42 @@
-using System;
+namespace DocFx.Plugin.LastModified.Helpers;
+
 using System.IO;
 using System.Linq;
 using LibGit2Sharp;
-using Microsoft.DocAsCode.Common;
 
-namespace DocFx.Plugin.LastModified.Helpers
+/// <summary>
+/// Provides methods for repository-related operations.
+/// </summary>
+public static class RepositoryHelper
 {
     /// <summary>
-    ///     Provides methods for repository-related operations.
+    /// Returns the commit information for the specified file.
     /// </summary>
-    public static class RepositoryHelper
+    /// <param name="repo">The repository to query against.</param>
+    /// <param name="srcPath">The path of the file.</param>
+    /// <returns>
+    /// A <see cref="Commit"/> object containing the information of the commit.
+    /// </returns>
+    public static Commit? GetCommitInfo(this Repository repo, string srcPath)
     {
-        /// <summary>
+        var gitDir = repo.Info.Path
-        ///     Returns the commit information for the specified file.
+            .Replace(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar);
-        /// </summary>
+        var repoRoot = Path.Join(gitDir, "..");
-        /// <param name="repo">The repository to query against.</param>
+
-        /// <param name="srcPath">The path of the file.</param>
+        if (string.IsNullOrEmpty(repoRoot))
-        /// <returns>
-        ///     A <see cref="Commit"/> object containing the information of the commit.
-        /// </returns>
-        public static Commit GetCommitInfo(this Repository repo, string srcPath)
         {
-            if (repo == null) throw new ArgumentNullException(nameof(repo));
+            throw new DirectoryNotFoundException("Cannot obtain the root directory of the repository.");
-            if (srcPath == null) throw new ArgumentNullException(nameof(srcPath));
+        }
 
-            // Hacky solution because libgit2sharp does not provide an easy way
+        var relativePath = Path
-            // to get the root dir of the repo
+            .GetRelativePath(repoRoot, Path.GetFullPath(srcPath))
-            // and for some reason does not work with forward-slash
+            .Replace(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar);
-            var repoRoot = repo.Info.Path.Replace('\\', '/').Replace(".git/", "");
-            if (string.IsNullOrEmpty(repoRoot))
-                throw new DirectoryNotFoundException("Cannot obtain the root directory of the repository.");
-            Logger.LogVerbose($"Repository root: {repoRoot}");
 
-            // Remove root dir from absolute path to transform into relative path
+        // See libgit2sharp#1520 for sort issue
-            var sourcePath = srcPath.Replace('\\', '/').Replace(repoRoot, "");
+        var logEntry = repo.Commits
-            Logger.LogVerbose($"Obtaining information from {sourcePath}, from repo {repo.Info.Path}...");
+            .QueryBy(relativePath, new CommitFilter { SortBy = CommitSortStrategies.Topological })
+            .FirstOrDefault();
 
-            // See libgit2sharp#1520 for sort issue
+        return logEntry?.Commit;
-            var logEntry = repo.Commits
-                .QueryBy(sourcePath, new CommitFilter {SortBy = CommitSortStrategies.Topological})
-                .FirstOrDefault();
-            Logger.LogVerbose($"Finished query for {sourcePath}.");
-            return logEntry?.Commit;
-        }
     }
-}
+}

build/DocFx.Plugin.LastModified/Helpers/StringHelper.cs

@@ -1,42 +1,54 @@
-using System.Linq;
+namespace DocFx.Plugin.LastModified.Helpers;
 
-namespace DocFx.Plugin.LastModified.Helpers
+using System.Linq;
+
+/// <summary>
+/// Extensions for <see cref="string"/>.
+/// </summary>
+public static class StringHelper
 {
-    public static class StringHelper
+    /// <summary>
+    ///     Truncates the string to match the specified <paramref name="length"/>.
+    /// </summary>
+    /// <remarks>
+    ///     <para>This method is retrieved and modified from Humanizr/Humanizer.</para>
+    ///     <para>MIT License (c)</para>
+    ///     <para>Copyright (c) .NET Foundation and Contributors</para>
+    /// </remarks>
+    /// <param name="value">The string to truncate.</param>
+    /// <param name="length">The target maximum length of the string.</param>
+    /// <returns>
+    ///     A truncated string based on the <paramref name="length" /> specified.
+    /// </returns>
+    public static string Truncate(this string value, int length)
     {
-        /// <summary>
+        const string truncationString = "...";
-        ///     Truncates the string to match the specified <paramref name="length"/>.
-        /// </summary>
-        /// <remarks>
-        ///     <para>This method is retrieved and modified from Humanizr/Humanizer.</para>
-        ///     <para>MIT License (c)</para>
-        ///     <para>Copyright (c) .NET Foundation and Contributors</para>
-        /// </remarks>
-        /// <param name="value">The string to truncate.</param>
-        /// <param name="length">The target maximum length of the string.</param>
-        /// <returns>
-        ///     A truncated string based on the <paramref name="length" /> specified.
-        /// </returns>
-        public static string Truncate(this string value, int length)
-        {
-            var truncationString = "...";
 
-            if (value == null) return null;
+        if (value.Length == 0)
-            if (value.Length == 0) return value;
+        {
+            return value;
+        }
 
-            var alphaNumericalCharactersProcessed = 0;
+        var alphaNumericalCharactersProcessed = 0;
 
-            if (value.ToCharArray().Count(char.IsLetterOrDigit) <= length) return value;
+        if (value.ToCharArray().Count(char.IsLetterOrDigit) <= length)
+        {
+            return value;
+        }
 
-            for (var i = 0; i < value.Length - truncationString.Length; i++)
+        for (var i = 0; i < value.Length - truncationString.Length; i++)
+        {
+            if (char.IsLetterOrDigit(value[i]))
             {
-                if (char.IsLetterOrDigit(value[i])) alphaNumericalCharactersProcessed++;
+                alphaNumericalCharactersProcessed++;
-
-                if (alphaNumericalCharactersProcessed + truncationString.Length == length)
-                    return value.Substring(0, i + 1) + truncationString;
             }
 
-            return value;
+            if (alphaNumericalCharactersProcessed + truncationString.Length == length)
+            {
+                return value[.. (i + 1)] + truncationString;
+            }
         }
+
+        return value;
     }
-}
+}

build/DocFx.Plugin.LastModified/LastModifiedInfo.cs

@@ -0,0 +1,21 @@
+namespace DocFx.Plugin.LastModified;
+
+using System;
+
+public record LastModifiedInfo
+{
+    /// <summary>
+    /// Gets the last modified date of the file.
+    /// </summary>
+    public DateTimeOffset LastModified { get; init; }
+
+    /// <summary>
+    /// Gets the commit header, if any.
+    /// </summary>
+    public string CommitHeader { get; init; } = string.Empty;
+
+    /// <summary>
+    /// Gets the commit body, if any.
+    /// </summary>
+    public string CommitBody { get; init; } = string.Empty;
+}

build/DocFx.Plugin.LastModified/LastModifiedPostProcessor.cs

@@ -1,171 +1,56 @@
-using System;
+namespace DocFx.Plugin.LastModified;
+
+using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Composition;
-using System.IO;
 using System.Linq;
 using System.Reflection;
-using System.Text;
+using Docfx.Common;
-using DocFx.Plugin.LastModified.Helpers;
+using Docfx.Plugins;
-using HtmlAgilityPack;
+using Processors;
-using LibGit2Sharp;
+
-using Microsoft.DocAsCode.Common;
+/// <summary>
-using Microsoft.DocAsCode.Plugins;
+/// Post-processor responsible for injecting last modified date according to commit or file modified date.
-
+/// </summary>
-namespace DocFx.Plugin.LastModified
+[Export(nameof(LastModifiedPostProcessor), typeof(IPostProcessor))]
+public class LastModifiedPostProcessor : IPostProcessor
 {
-    /// <summary>
+    private int _addedFiles;
-    ///     Post-processor responsible for injecting last modified date according to commit or file modified date.
-    /// </summary>
-    [Export(nameof(LastModifiedPostProcessor), typeof(IPostProcessor))]
-    public class LastModifiedPostProcessor : IPostProcessor
-    {
-        private int _addedFiles;
-        private Repository _repo;
-
-        public ImmutableDictionary<string, object> PrepareMetadata(ImmutableDictionary<string, object> metadata)
-            => metadata;
-
-        public Manifest Process(Manifest manifest, string outputFolder)
-        {
-            var versionInfo = Assembly.GetExecutingAssembly()
-                                  .GetCustomAttribute<AssemblyInformationalVersionAttribute>()
-                                  ?.InformationalVersion ??
-                              Assembly.GetExecutingAssembly().GetName().Version?.ToString();
-            Logger.LogInfo($"Version: {versionInfo}");
-            Logger.LogInfo("Begin adding last modified date to items...");
-
-            // attempt to fetch git repo from the current project
-            var gitDirectory = Repository.Discover(manifest.SourceBasePath);
-            if (gitDirectory != null) _repo = new Repository(gitDirectory);
 
-            foreach (var manifestItem in manifest.Files.Where(x => x.DocumentType == "Conceptual"))
+    private IEnumerable<IProcessor> Processors { get; } = new List<IProcessor>
-            foreach (var manifestItemOutputFile in manifestItem.OutputFiles)
+    {
-            {
+        new ConceptualProcessor(),
-                var sourcePath = Path.Combine(manifest.SourceBasePath, manifestItem.SourceRelativePath);
+        new ManagedReferenceProcessor(),
-                var outputPath = Path.Combine(outputFolder, manifestItemOutputFile.Value.RelativePath);
+    };
-                if (_repo != null)
-                {
-                    var commitInfo = _repo.GetCommitInfo(sourcePath);
-                    if (commitInfo != null)
-                    {
-                        Logger.LogVerbose("Assigning commit date...");
-                        var lastModified = commitInfo.Author.When;
-
-                        var commitHeaderBuilder = new StringBuilder();
-                        Logger.LogVerbose("Appending commit author and email...");
-                        commitHeaderBuilder.AppendLine($"Author:    {commitInfo.Author.Name}");
-                        Logger.LogVerbose("Appending commit SHA...");
-                        commitHeaderBuilder.AppendLine($"Commit:    {commitInfo.Sha}");
-                        
-                        var commitHeader = commitHeaderBuilder.ToString();
-                        // truncate to 200 in case of huge commit body
-                        var commitBody = commitInfo.Message.Truncate(300);
-                        Logger.LogVerbose($"Writing {lastModified} with reason for {outputPath}...");
-                        WriteModifiedDate(outputPath, lastModified, commitHeader, commitBody);
-                        continue;
-                    }
-                }
 
-                var fileLastModified = File.GetLastWriteTimeUtc(sourcePath);
+    /// <inheritdoc />
-                Logger.LogVerbose($"Writing {fileLastModified} for {outputPath}...");
+    public ImmutableDictionary<string, object> PrepareMetadata(ImmutableDictionary<string, object> metadata)
-                WriteModifiedDate(outputPath, fileLastModified);
+        => metadata;
-            }
 
-            // dispose repo after usage
+    /// <inheritdoc />
-            _repo?.Dispose();
+    public Manifest Process(Manifest manifest, string outputFolder)
+    {
+        var versionInfo = Assembly.GetExecutingAssembly().GetName().Version;
 
-            Logger.LogInfo($"Added modification date to {_addedFiles} conceptual articles.");
+        Logger.LogInfo($"Version: {versionInfo}");
-            return manifest;
+        Logger.LogInfo("Begin adding last modified date to items...");
-        }
 
-        private void WriteModifiedDate(string outputPath, DateTimeOffset modifiedDate, string commitHeader = null,
+        foreach (var manifestItem in manifest.Files)
-            string commitBody = null)
         {
-            if (outputPath == null) throw new ArgumentNullException(nameof(outputPath));
+            var processor = Processors.FirstOrDefault(p => p.Supports(manifestItem.Type));
-
+            if (processor == null)
-            // load the document
-            var htmlDoc = new HtmlDocument();
-            htmlDoc.Load(outputPath);
-
-            // check for article container
-            var articleNode = htmlDoc.DocumentNode.SelectSingleNode("//article[contains(@class, 'content wrap')]");
-            if (articleNode == null)
             {
-                Logger.LogDiagnostic("ArticleNode not found, returning.");
+                Logger.LogDiagnostic($"No processor found for {manifestItem.Type}, skipping.");
-                return;
+                continue;
             }
 
-            var paragraphNode = htmlDoc.CreateElement("p");
+            if (processor.TryProcess(manifest, manifestItem, outputFolder))
-            paragraphNode.InnerHtml = $"This page was last modified at {modifiedDate} (UTC).";
-            var separatorNode = htmlDoc.CreateElement("hr");
-            articleNode.AppendChild(separatorNode);
-            articleNode.AppendChild(paragraphNode);
-
-            if (!string.IsNullOrEmpty(commitHeader))
             {
-                // inject collapsible container script
+                _addedFiles++;
-                InjectCollapseScript(htmlDoc);
-
-                // create collapse container
-                var collapsibleNode = htmlDoc.CreateElement("div");
-                collapsibleNode.SetAttributeValue("class", "collapse-container last-modified");
-                collapsibleNode.SetAttributeValue("id", "accordion");
-                var reasonHeaderNode = htmlDoc.CreateElement("span");
-                reasonHeaderNode.InnerHtml = "<span class=\"arrow-r\"></span>Commit Message";
-                var reasonContainerNode = htmlDoc.CreateElement("div");
-
-                // inject header
-                var preCodeBlockNode = htmlDoc.CreateElement("pre");
-                var codeBlockNode = htmlDoc.CreateElement("code");
-                codeBlockNode.InnerHtml = commitHeader;
-                preCodeBlockNode.AppendChild(codeBlockNode);
-                reasonContainerNode.AppendChild(preCodeBlockNode);
-                
-                // inject body
-                preCodeBlockNode = htmlDoc.CreateElement("pre");
-                codeBlockNode = htmlDoc.CreateElement("code");
-                codeBlockNode.SetAttributeValue("class", "xml");
-                codeBlockNode.InnerHtml = commitBody;
-                preCodeBlockNode.AppendChild(codeBlockNode);
-                reasonContainerNode.AppendChild(preCodeBlockNode);
-
-                // inject the entire block
-                collapsibleNode.AppendChild(reasonHeaderNode);
-                collapsibleNode.AppendChild(reasonContainerNode);
-                articleNode.AppendChild(collapsibleNode);
             }
-
-            htmlDoc.Save(outputPath);
-            _addedFiles++;
         }
 
-        /// <summary>
+        Logger.LogInfo($"Added modification date to {_addedFiles} articles.");
-        ///     Injects script required for collapsible dropdown menu.
+        return manifest;
-        /// </summary>
-        /// <seealso cref="!:https://github.com/jordnkr/collapsible" />
-        private static void InjectCollapseScript(HtmlDocument htmlDoc)
-        {
-            var bodyNode = htmlDoc.DocumentNode.SelectSingleNode("//body");
-
-            var accordionNode = htmlDoc.CreateElement("script");
-            accordionNode.InnerHtml = @"
-  $( function() {
-    $( ""#accordion"" ).collapsible();
-  } );";
-            bodyNode.AppendChild(accordionNode);
-
-            var collapsibleScriptNode = htmlDoc.CreateElement("script");
-            collapsibleScriptNode.SetAttributeValue("type", "text/javascript");
-            collapsibleScriptNode.SetAttributeValue("src",
-                "https://cdn.rawgit.com/jordnkr/collapsible/master/jquery.collapsible.min.js");
-            bodyNode.AppendChild(collapsibleScriptNode);
-
-            var headNode = htmlDoc.DocumentNode.SelectSingleNode("//head");
-            var collapsibleCssNode = htmlDoc.CreateElement("link");
-            collapsibleCssNode.SetAttributeValue("rel", "stylesheet");
-            collapsibleCssNode.SetAttributeValue("href",
-                "https://cdn.rawgit.com/jordnkr/collapsible/master/collapsible.css");
-            headNode.AppendChild(collapsibleCssNode);
-        }
     }
-}
+}

build/DocFx.Plugin.LastModified/Processors/AbstractProcessor.cs

@@ -0,0 +1,116 @@
+namespace DocFx.Plugin.LastModified.Processors;
+
+using Docfx.Common;
+using Docfx.Plugins;
+using HtmlAgilityPack;
+
+/// <summary>
+/// An abstract processor for adding last modified date to articles, contains common methods.
+/// </summary>
+public abstract class AbstractProcessor : IProcessor
+{
+    /// <summary>
+    /// Determines whether this processor supports the given type.
+    /// </summary>
+    /// <param name="type">The type of manifest item.</param>
+    /// <returns>True if this processor supports the given type, false otherwise.</returns>
+    public abstract bool Supports(string type);
+
+    /// <summary>
+    /// Processes the given manifest item.
+    /// </summary>
+    /// <param name="manifest">The <see cref="Manifest"/> that contains the manifest item.</param>
+    /// <param name="manifestItem">The <see cref="ManifestItem"/> to process.</param>
+    /// <param name="outputFolder">The output folder.</param>
+    public abstract void Process(Manifest manifest, ManifestItem manifestItem, string outputFolder);
+
+    /// <summary>
+    /// Attempts to process the given manifest item.
+    /// </summary>
+    /// <param name="manifest">The <see cref="Manifest"/> that contains the manifest item.</param>
+    /// <param name="manifestItem">The <see cref="ManifestItem"/> to process.</param>
+    /// <param name="outputFolder">The output folder.</param>
+    /// <returns>True if the manifest item was processed, false otherwise.</returns>
+    public bool TryProcess(Manifest manifest, ManifestItem manifestItem, string outputFolder)
+    {
+        if (!Supports(manifestItem.Type))
+        {
+            Logger.LogVerbose($"Skipping {manifestItem.Type}...");
+            return false;
+        }
+
+        Logger.LogDiagnostic($"Processing {manifestItem.Type}...");
+        Process(manifest, manifestItem, outputFolder);
+        return true;
+    }
+
+    /// <summary>
+    /// Builds the last modified info for the given file path.
+    /// </summary>
+    /// <param name="filePath">The file path.</param>
+    /// <returns>The <see cref="LastModifiedInfo"/> for the given file path.</returns>
+    protected abstract LastModifiedInfo GetLastModifiedInfo(string filePath);
+
+    /// <summary>
+    /// Modifies the given document with the given last modified info.
+    /// </summary>
+    /// <param name="filePath">The file path to the document.</param>
+    /// <param name="lastModifiedInfo">The <see cref="LastModifiedInfo"/> to use.</param>
+    protected virtual void ModifyDocument(string filePath, LastModifiedInfo lastModifiedInfo)
+    {
+        var htmlDocument = new HtmlDocument();
+        htmlDocument.Load(filePath);
+
+        var articleNode = htmlDocument.DocumentNode.SelectSingleNode("//article");
+        if (articleNode == null)
+        {
+            Logger.LogWarning($"No article node found in {filePath}.");
+            return;
+        }
+
+        var separatorNode = htmlDocument.CreateElement("hr");
+        articleNode.AppendChild(separatorNode);
+
+        var lastModifiedNode = htmlDocument.CreateElement("div");
+        lastModifiedNode.SetAttributeValue("class", "last-modified");
+        articleNode.AppendChild(lastModifiedNode);
+
+        var paragraphNode = htmlDocument.CreateElement("p");
+        paragraphNode.InnerHtml = $"This page was last modified at {lastModifiedInfo.LastModified} (UTC).";
+        lastModifiedNode.AppendChild(paragraphNode);
+
+        if (string.IsNullOrEmpty(lastModifiedInfo.CommitHeader))
+        {
+            htmlDocument.Save(filePath);
+            return;
+        }
+
+        var collapsibleNode = htmlDocument.CreateElement("details");
+        lastModifiedNode.AppendChild(collapsibleNode);
+
+        var reasonHeaderNode = htmlDocument.CreateElement("summary");
+        reasonHeaderNode.SetAttributeValue("style", "display: list-item;");
+        reasonHeaderNode.InnerHtml = "Commit Message";
+        collapsibleNode.AppendChild(reasonHeaderNode);
+
+        var reasonContainerNode = htmlDocument.CreateElement("div");
+        collapsibleNode.AppendChild(reasonContainerNode);
+
+        var preCodeBlockNode = htmlDocument.CreateElement("pre");
+        var codeBlockNode = htmlDocument.CreateElement("code");
+        codeBlockNode.InnerHtml = lastModifiedInfo.CommitHeader;
+        preCodeBlockNode.AppendChild(codeBlockNode);
+        reasonContainerNode.AppendChild(preCodeBlockNode);
+
+        if (!string.IsNullOrEmpty(lastModifiedInfo.CommitBody))
+        {
+            preCodeBlockNode = htmlDocument.CreateElement("pre");
+            codeBlockNode = htmlDocument.CreateElement("code");
+            codeBlockNode.InnerHtml = lastModifiedInfo.CommitBody;
+            preCodeBlockNode.AppendChild(codeBlockNode);
+            reasonContainerNode.AppendChild(preCodeBlockNode);
+        }
+
+        htmlDocument.Save(filePath);
+    }
+}

build/DocFx.Plugin.LastModified/Processors/ConceptualProcessor.cs

@@ -0,0 +1,74 @@
+namespace DocFx.Plugin.LastModified.Processors;
+
+using System;
+using System.IO;
+using System.Text;
+using Docfx.Common;
+using Docfx.Plugins;
+using Helpers;
+using LibGit2Sharp;
+
+/// <summary>
+/// Processor for adding last modified date to conceptual articles.
+/// </summary>
+public class ConceptualProcessor : AbstractProcessor
+{
+    private Repository? _repo;
+
+    /// <inheritdoc />
+    public override bool Supports(string type)
+    {
+        return type == "Conceptual";
+    }
+
+    /// <inheritdoc />
+    public override void Process(Manifest manifest, ManifestItem manifestItem, string outputFolder)
+    {
+        var repository = Repository.Discover(manifest.SourceBasePath);
+        if (repository != null)
+        {
+            _repo = new Repository(repository);
+        }
+
+        var sourcePath = Path.Combine(manifest.SourceBasePath, manifestItem.SourceRelativePath);
+        var outputPath = Path.Combine(outputFolder, manifestItem.Output[".html"].RelativePath);
+
+        var lastModifiedInfo = GetLastModifiedInfo(sourcePath);
+
+        ModifyDocument(outputPath, lastModifiedInfo);
+    }
+
+    /// <inheritdoc />
+    protected override LastModifiedInfo GetLastModifiedInfo(string filePath)
+    {
+        var lastModified = DateTimeOffset.MinValue;
+        var commitHeader = string.Empty;
+        var commitBody = string.Empty;
+
+        if (_repo?.GetCommitInfo(filePath) is { } commitInfo)
+        {
+            lastModified = commitInfo.Author.When;
+            Logger.LogDiagnostic($"Last modified date: {lastModified} (UTC)");
+
+            var commitHeaderBuilder = new StringBuilder();
+            commitHeaderBuilder.AppendLine($"Author:    {commitInfo.Author.Name}");
+            commitHeaderBuilder.AppendLine($"Commit:    {commitInfo.Sha}");
+
+            commitHeader = commitHeaderBuilder.ToString();
+            commitBody = commitInfo.Message.Truncate(300);
+        }
+
+        if (lastModified == DateTimeOffset.MinValue)
+        {
+            lastModified = File.GetLastWriteTimeUtc(filePath);
+            Logger.LogVerbose($"Last modified date: {lastModified} (UTC)");
+        }
+
+        return new LastModifiedInfo
+        {
+            LastModified = lastModified,
+            CommitHeader = commitHeader,
+            CommitBody = commitBody,
+        };
+    }
+}

build/DocFx.Plugin.LastModified/Processors/IProcessor.cs

@@ -0,0 +1,12 @@
+namespace DocFx.Plugin.LastModified.Processors;
+
+using Docfx.Plugins;
+
+public interface IProcessor
+{
+    bool Supports(string type);
+    
+    void Process(Manifest manifest, ManifestItem manifestItem, string outputFolder);
+    
+    bool TryProcess(Manifest manifest, ManifestItem manifestItem, string outputFolder);
+}

build/DocFx.Plugin.LastModified/Processors/ManagedReferenceProcessor.cs

@@ -0,0 +1,93 @@
+namespace DocFx.Plugin.LastModified.Processors;
+
+using System;
+using System.IO;
+using System.Linq;
+using Docfx.Common;
+using Docfx.Plugins;
+using Files;
+using Helpers;
+using LibGit2Sharp;
+using YamlDotNet.Serialization;
+using YamlDotNet.Serialization.NamingConventions;
+
+/// <summary>
+/// Processor for adding last modified date to managed reference articles.
+/// </summary>
+public class ManagedReferenceProcessor : AbstractProcessor
+{
+    private readonly Deserializer _deserializer = Deserializer.FromValueDeserializer(
+        new DeserializerBuilder()
+            .WithNamingConvention(CamelCaseNamingConvention.Instance)
+            .IgnoreUnmatchedProperties()
+            .BuildValueDeserializer());
+
+    private Repository? _repo;
+    private Manifest? _manifest;
+
+    /// <inheritdoc />
+    public override bool Supports(string type)
+    {
+        return type == "ManagedReference";
+    }
+
+    /// <inheritdoc />
+    public override void Process(Manifest manifest, ManifestItem manifestItem, string outputFolder)
+    {
+        var repository = Repository.Discover(manifest.SourceBasePath);
+        if (repository != null)
+        {
+            _repo = new Repository(repository);
+        }
+
+        _manifest = manifest;
+
+        var sourcePath = Path.Combine(manifest.SourceBasePath, manifestItem.SourceRelativePath);
+        var outputPath = Path.Combine(outputFolder, manifestItem.Output[".html"].RelativePath);
+
+        var lastModifiedInfo = GetLastModifiedInfo(sourcePath);
+
+        ModifyDocument(outputPath, lastModifiedInfo);
+    }
+
+    /// <inheritdoc />
+    protected override LastModifiedInfo GetLastModifiedInfo(string filePath)
+    {
+        var yml = File.ReadAllText(filePath);
+        var managedReferenceDocument = _deserializer.Deserialize<ManagedReferenceDocument?>(yml);
+        var itemSource = managedReferenceDocument?.Items?.FirstOrDefault(i => !string.IsNullOrEmpty(i.Source?.Path));
+        var itemSourcePath = itemSource?.Source?.Path ?? string.Empty;
+
+        var lastModified = DateTimeOffset.MinValue;
+        var commitHeader = string.Empty;
+        var commitBody = string.Empty;
+
+        var sourcePath = Path.Combine(_manifest?.SourceBasePath ?? string.Empty, itemSourcePath);
+
+        if (!string.IsNullOrEmpty(itemSourcePath) && _repo?.GetCommitInfo(sourcePath) is { } commitInfo)
+        {
+            lastModified = commitInfo.Author.When;
+            Logger.LogDiagnostic($"Last modified date: {lastModified} (UTC)");
+
+            var commitHeaderBuilder = new System.Text.StringBuilder();
+            commitHeaderBuilder.AppendLine($"Author:    {commitInfo.Author.Name}");
+            commitHeaderBuilder.AppendLine($"Commit:    {commitInfo.Sha}");
+
+            commitHeader = commitHeaderBuilder.ToString();
+            commitBody = commitInfo.Message.Truncate(300);
+        }
+
+        if (lastModified == DateTimeOffset.MinValue)
+        {
+            lastModified = File.GetLastWriteTimeUtc(sourcePath);
+            Logger.LogVerbose($"Last modified date: {lastModified} (UTC)");
+        }
+
+        return new LastModifiedInfo
+        {
+            LastModified = lastModified,
+            CommitHeader = commitHeader,
+            CommitBody = commitBody,
+        };
+    }
+}

build/DocFx.Plugin.LastModified/README.md

@@ -0,0 +1 @@
+Based on https://github.com/dhkatz/DocFx.Plugin.LastModified