GroupDocs.Markdown for .NET 26.3 Release Notes

This is a major release with a redesigned public API, custom DOM-based Markdown renderer, full Markdown flavor control, async API, and numerous bug fixes. The release also adds .NET 8 and .NET 10 support with per-TFM NuGet runtime packages.

Full list of changes in this release

Major Features

Custom DOM-Based Markdown Renderer

The library no longer delegates Markdown generation to a third-party export. A custom renderer walks the document object model node by node and produces Markdown directly, providing full control over every aspect of the output.

Word/PDF/Ebook/Text/CHM documents are rendered with support for paragraphs, headings (H1-H6), bold, italic, strikethrough, inline code, ordered and unordered lists with nesting, tables (GFM pipe syntax or CommonMark code block fallback), hyperlinks, and images.

Spreadsheets are rendered with cell-by-cell grid traversal, typed value formatting, worksheet sections, column/row truncation with ellipsis indicators, hidden sheet filtering, and custom sheet separators.

Static Convenience Methods

One-liner conversion methods that handle resource management automatically:

string md = MarkdownConverter.ToMarkdown("report.docx");
MarkdownConverter.ToFile("report.docx", "report.md");
IReadOnlyList<FileFormat> formats = MarkdownConverter.GetSupportedFormats();

Async API

Async counterparts for all static and instance methods with CancellationToken support:

string md = await MarkdownConverter.ToMarkdownAsync("report.docx");
await MarkdownConverter.ToFileAsync("large.pdf", "output.md");
DocumentInfo info = await MarkdownConverter.GetInfoAsync("report.docx");

Document Inspection Without Conversion

Retrieve document metadata without performing a full conversion:

DocumentInfo info = MarkdownConverter.GetInfo("report.docx");
Console.WriteLine($"{info.FileFormat}, {info.PageCount} pages, by {info.Author}");

Markdown Flavor Control

Target a specific Markdown dialect:

var options = new ConvertOptions { Flavor = MarkdownFlavor.GitHub };     // pipe tables, strikethrough
var options = new ConvertOptions { Flavor = MarkdownFlavor.CommonMark }; // tables as code blocks

Spreadsheet Rendering Options

Full control over how spreadsheets are rendered to Markdown:

var options = new ConvertOptions
{
    MaxColumns = 8,
    MaxRows = 50,
    SheetSeparator = "\n---\n",
    IncludeHiddenSheets = false
};

Heading Level Offset and YAML Front Matter

var options = new ConvertOptions
{
    HeadingLevelOffset = 2,       // # Title  ->  ### Title
    IncludeFrontMatter = true     // prepend YAML metadata
};

Conversion Warnings and Unified Error Model

All Convert() methods now throw on failure. ConvertResult carries non-fatal warnings:

ConvertResult result = converter.Convert();
foreach (string w in result.Warnings)
    Console.WriteLine(w);  // e.g. "Worksheet 'Data' truncated at 50 rows."

Image Replacement and Relative Paths

Replace images during conversion and control path references:

var strategy = new ExportImagesToFileSystemStrategy("c:/output/images")
{
    ImagesRelativePath = "images"  // ![](images/img-001.png)
};

Table of Contents Rendering

Documents with Table of Contents are rendered as clean lists instead of raw field codes:

- Introduction
- 1.  Executive Summary
- 2.  Company Overview

Bug Fixes

• Table of Contents field codes no longer leak as raw text (PAGEREF, HYPERLINK \l, TOC \o instructions). TOC entries are rendered as a plain list.
• Bold whitespace artifacts (** **) reduced through whitespace-aware formatting and post-processing cleanup.
• Control characters stripped from output — no more invisible characters in the Markdown.
• Table cell field codes no longer leak — cells are rendered through the inline content renderer instead of raw GetText().
• Uppercase file extensions (.PDF, .XLSX) are now recognized via case-insensitive matching.
• Hyperlink field codes no longer leak as HYPERLINK "http://..." in the output.
• Internal bookmarks rendered as plain text instead of broken \l references.
• Stack overflow via reflection fixed by removing the IoC container.
• FileStream leak in the file-path constructor fixed with proper using block.
• Generic error messages replaced with actual exception messages from the underlying library.
• Out-of-range page numbers skipped gracefully instead of causing failure.
• Custom exceptions (DocumentProtectedException, InvalidFormatException) now properly thrown.

Breaking Changes

Renamed Types

FileFormat Enum

Family-level values (FileFormat.WordProcessing, FileFormat.Spreadsheet) replaced with specific formats (FileFormat.Docx, FileFormat.Xlsx, etc.). New entries: FileFormat.Txt, FileFormat.Chm.

ConvertOptions and LoadOptions Separated

ConvertOptions no longer inherits LoadOptions. Password and format hints go on LoadOptions:

var loadOptions = new LoadOptions(FileFormat.Docx) { Password = "secret" };
var convertOptions = new ConvertOptions { HeadingLevelOffset = 1 };
using var converter = new MarkdownConverter("file.docx", loadOptions);
var result = converter.Convert(convertOptions);

Image and URI Strategies Split

Single ExportStrategy property replaced with two typed properties:

var options = new ConvertOptions
{
    ImageExportStrategy = new ExportImagesToFileSystemStrategy("images"),
    UriExportStrategy = new CustomUriExportStrategy(handler)
};

Delegates Replaced with Interfaces

CustomImagesStrategy and CustomUriExportStrategy now accept IImageSavingHandler and IUriSavingHandler interfaces instead of delegate callbacks.

LoadOptions.Extension and LoadOptions.MimeType Are Internal

Use new LoadOptions(FileFormat.Docx) instead of setting Extension or MimeType directly.

Public API changes

New public types

• DocumentInfo — document metadata (format, page count, title, author, encryption status)
• MarkdownFlavor — enum for target Markdown dialect (GitHub, CommonMark)
• IImageSavingHandler — interface for custom image saving callbacks
• IUriSavingHandler — interface for custom URI saving callbacks
• GroupDocsMarkdownException — general conversion exception
• InvalidFormatException — corrupt or unrecognized file format
• DocumentProtectedException — wrong or missing password

New static methods on MarkdownConverter

• ToMarkdown(string sourcePath) and overloads with LoadOptions/ConvertOptions
• ToFile(string sourcePath, string outputPath) and overloads
• GetInfo(string sourcePath) and overloads
• GetSupportedFormats()
• Async variants: ToMarkdownAsync, ToFileAsync, GetInfoAsync

New instance methods on MarkdownConverter

• GetDocumentInfo()
• ConvertAsync() and overloads

New properties on ConvertOptions

• ImageExportStrategy (replaces ExportStrategy)
• UriExportStrategy
• HeadingLevelOffset
• IncludeFrontMatter
• Flavor
• MaxColumns, MaxRows, SheetSeparator, IncludeHiddenSheets

New properties on ConvertResult

• Warnings — non-fatal conversion warnings

New properties on ExportImagesToFileSystemStrategy and CustomImagesStrategy

• ImagesRelativePath — controls the path written in Markdown image references

New methods on CustomImageSavingArgs

• SetReplacementImage(Stream imageStream) — substitute image content

Removed types

• IExportStrategy — replaced by IImageExportStrategy and IUriExportStrategy
• DocumentConverterOptions — renamed to ConvertOptions
• DocumentConverterResult — renamed to ConvertResult

Requirements

• .NET 6.0+, .NET 8.0+, .NET 10.0+ (Windows or Linux)
• .NET Framework 4.6.2+ (Windows)

License

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