repository·master·Indexed 18 days ago
https://github.com/mysticmind/reversemarkdown-netA high-performance HTML to Markdown converter library for C# using AngleSharp for HTML5 parsing. It supports multiple Markdown flavors including GitHub, CommonMark, Slack, Telegram, MultiMarkdown, and Pandoc. Version 6 introduces a Markdown DOM architecture that decouples parsing from rendering, allowing for structured document manipulation. The library targets netstandard2.0, net8.0, net9.0, and net10.0, and is compatible with .NET Framework 4.6.1+, .NET Core 2.0+, Mono, and Unity.
ReverseMarkdown is a high-performance HTML to Markdown converter for C# that uses AngleSharp for HTML5 parsing. Key capabilities include:
Default, GitHub, CommonMark, Slack, Telegram, MultiMarkdown, and Pandoc via the MarkdownFlavor enum.IMdReader and the [MarkdownReader] attribute, as well as a Parse/Render Markdown DOM for transformations.netstandard2.0, net8.0, net9.0, and net10.0. It is compatible with .NET Framework 4.6.1+, .NET Core 2.0+, Mono, and Unity.RegisterReader to add custom readers.ReverseMarkdown targets netstandard2.0, net8.0, net9.0, and net10.0.
Because it targets netstandard2.0, it is compatible with the following runtimes:
It also supports modern .NET (8, 9, and 10).
Starting with v6, ReverseMarkdown uses an intermediate Markdown DOM (an mdast-equivalent typed document tree) to decouple HTML parsing from Markdown rendering. This architecture splits the conversion process into two distinct phases:
Parse): Readers convert HtmlNode objects into a rich, flavor-agnostic Markdown DOM. This phase builds a superset tree containing all possible structural information.Render): Writers take the Markdown DOM and convert it into a specific Markdown flavor string. Writers own all flavor-specific logic and decisions regarding how to represent (or degrade) nodes that a specific flavor cannot support.This design allows you to perform structured operations on the document—such as querying, pruning, or reshaping the tree—before finally rendering it to a string. This is particularly useful if you need to filter specific parts of the document based on its Markdown structure rather than just its HTML attributes.
The MarkdownFlavor enum is now the single, canonical way to select a flavor. Several previous flavor types are now obsolete aliases of Flavor.
SlackFlavored (now Flavor)TelegramMarkdownV2 (now Flavor)CommonMark (now Flavor)GithubFlavored remains distinct. It produces clean GFM markdown using the default writer. Do not confuse it with Flavor = MarkdownFlavor.GitHub, which is a CommonMark-based writer that preserves raw HTML.
SlackFlavored = true switch is a legacy option and is now considered an obsolete alias. For future compatibility, replace it with the explicit Flavor = MarkdownFlavor.Slack setting in your ConversionOptions.ReverseMarkdown allows you to select the output format using a single Flavor enum. The supported flavors are:
cmark-gfm)cmark-gfm)pandoc)pandoc)The CommonMark flavor is designed for round-trip-faithful conversion. It preserves soft line breaks, escapes markup-significant characters, and escapes line-start markers to ensure literal text is not reinterpreted during conversion.
Note: The legacy CommonMark = true switch is an obsolete alias for Flavor = MarkdownFlavor.CommonMark and should be avoided in favor of the explicit flavor setting.
// Use the explicit flavor instead of the obsolete CommonMark = true switch
var converter = new ReverseMarkdownConverter(new ConversionOptions
{
Flavor = MarkdownFlavor.CommonMark
});In version 6 of ReverseMarkdown, the HTML parsing engine has transitioned from HtmlAgilityPack to AngleSharp. This change introduces a breaking change to the public API surface for readers:
IConverter interface exposed HtmlNode (from HtmlAgilityPack).IMdReader.Read method now exposes IElement (from AngleSharp).When implementing or using custom readers in v6, you must work with AngleSharp.IElement instead of HtmlAgilityPack.HtmlNode. This transition provides spec-compliant tree construction, native CSS selector support via QuerySelector, and automatic entity decoding through IText.Data and GetAttribute.
You can reuse the conversion logic of an existing tag for a different tag using Tags.Aliases. The key in the dictionary is the tag you want to remap, and the value is the tag it should be converted as.
// Example mapping: treat 'span' as 'em' (italics)
var converter = new ReverseMarkdown.Converter(new ConversionOptions {
Tags = new Tags {
Aliases = new Dictionary<string, string> { { "span", "em" } }
}
});When using MarkdownFlavor.Telegram, the following conversion behaviors are applied to ensure compatibility with Telegram's strict escaping rules:
1\.) and unordered (\-) lists are also escaped.<img> tags are converted to link labels using the format [Image: alt](url).<table> tags fall back to a preformatted code block representation.<sup> tags fall back to caret notation (e.g., x^2).