Skip to content

Flayms/Markdown2Pdf

Repository files navigation

Nuget Version NuGet Downloads Build and Release

Markdown2Pdf

Logo

.NET library for converting Markdown to PDF. Uses Markdig for converting markdown to HTML and then Puppeteer Sharp to convert that output to PDF.

For a cross-platform cli-application using this package checkout Markdown2Pdf.Console.

demo

A full demo PDF can be found here!

Usage

C#:

var converter = new Markdown2PdfConverter();
var resultPath = await converter.Convert("README.md");

VB.NET:

Dim converter As New Markdown2PdfConverter()
Dim resultPath As String = Await converter.Convert("README.md")

An enumeration of markdown files can also be passed to the converter, combining them into one PDF.

Wiki

Checkout the Wiki for more documentation.

Options

To further specify the conversion process, pass Markdown2PdfOptions to the converter:

var options = new Markdown2PdfOptions {
  HeaderHtml = "<div class=\"document-title\" style=\"background-color: #5eafed; width: 100%; padding: 5px\"></div>",
  FooterHtml = "<div style=\"background-color: #5eafed; width: 100%; padding: 5px\">Page <span class=\"pageNumber\"></span>/<span class=\"totalPages\"></span></div>",
  DocumentTitle = "Example PDF",
};
var converter = new Markdown2PdfConverter(options);

Alternatively the Markdown2PdfOptions can be loaded from a YAML Front Matter block at the start of the markdown file:

var converter = Markdown2PdfConverter.CreateWithInlineOptionsFromFile("README.md");
var resultPath = await converter.Convert("README.md");

Usage examples for this can be found here.

Option Description
ChromePath Path to chrome or chromium executable or self-downloads it if null.
CodeHighlightTheme The theme to use for highlighting code blocks.
CustomHeadContent A string containing any content valid inside a HTML <head> to apply extra scripting / styling to the document.
DocumentTitle The title of this document. Can be injected into the header / footer by adding the class document-title to the element.
EnableAutoLanguageDetection Auto detect the language for code blocks without specfied language.
FooterHtml HTML-string to use as the document footer.
Format The paper format for the PDF.
HeaderHtml HTML-string to use as the document header.
IsLandscape Paper orientation.
KeepHtml true if the created HTML should not be deleted.
MarginOptions Css-margins for the sides of the document.
ModuleOptions Options that decide from where to load additional modules. More Information.
Scale Scale of the content. Must be between 0.1 and 2.
TableOfContents Creates a TOC from the markdown headers. More Information.
Theme The styling to apply to the document.

Table of contents

To add a table of contents insert

  • [TOC] (Gitlab Syntax)
  • [[_TOC_]] (Gitlab Syntax)
  • or <!-- toc --> (Comment)

into the markdown document and use the Markdown2PdfOptions.TableOfContents option:

# My Document

[TOC]
...

Example creating a TOC:

options.TableOfContents = new TableOfContentsOptions {
  ListStyle = ListStyle.Decimal,

  // Include all heading levels from 2 to 4.
  MinDepthLevel = 2,
  MaxDepthLevel = 4
};

A header can be omitted from the toc by ending it with <!-- omit from toc -->:

## This header won't be displayed in the TOC <!-- omit from toc -->

The TOC gets generated within a <nav class="table-of-contents">. This can be used to apply extra custom styles.

Options

Option Description
HasColoredLinks If set, the titles in the TOC get default link markup.
ListStyle Decides which characters to use before the TOC titles.
MaxDepthLevel The maximum level of heading depth to include in the TOC.
MinDepthLevel The minimum level of heading depth to include in the TOC.
PageNumberOptions If set, the TOC will be generated with page numbers.

Modules

This library uses node_modules packages. By default they're loaded over the CDN they're hosted on e.g. https://cdn.jsdelivr.net.

You can also use a local installation by installing the following packages and setting Markdown2PdfOptions.ModuleOptions to ModuleOptions.FromLocalPath():

npm i mathjax@3
npm i mermaid@10
npm i font-awesome
npm i @highlightjs/cdn-assets@11
npm i github-markdown-css
npm i latex.css

Note: For this you need to have npm installed and added to PATH.

Module Description
MathJax Latex-Math rendering
Mermaid Diagrams
Font-Awesome Icons (Supported within mermaid diagrams)
Highlight.js Syntax highlighting
github-markdown-css Github-Theme
latex-css Latex-Theme

Further modification

To get more control over the HTML generation (e.g. to add your own JS-Scripts), modify the converter.ContentTemplate.

Unit-Tests

For automated tests, the project Markdown2Pdf.Tests exists. Before starting these, run setup.ps1.

Running in Docker

The bundled Chromium that gets installed by Puppeteer doesn't ship with all necessary dependencies (See Running Puppeteer in Docker).

To resolve this install them in your .dockerfile:

RUN apt-get update \
    && apt-get install -y wget gnupg \
    && wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add - \
    && sh -c 'echo "deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list' \
    && apt-get update \
    && apt-get install -y google-chrome-stable fonts-ipafont-gothic fonts-wqy-zenhei fonts-thai-tlwg fonts-kacst fonts-freefont-ttf libxss1 \
      --no-install-recommends \
    && rm -rf /var/lib/apt/lists/*

Why is Chromium needed

Markdown was initially developed so that it can be converted to HTML. Resulting from that, a lot of its tooling exists within the JavaScript world. For instance, Mermaid is only implemented in JavaScript, so we need a JS-engine to support it. This results in this package being slower but also able to support more features than other solutions that directly generate the PDF from Markdown.