Customizing document styles with FSharp.Markdown.Pdf

Yan Cui

I help clients go faster for less using serverless technologies.

Following on from my last post on formatting a Markdown document into PDF using FSharp.Markdown.Pdf, if you don’t like the default styling (which I tried to mimic style Github formats Markdown documents with) you can set your own styling for the different types of Markdown elements by going down a level of abstraction.

The FSharp.Markdown.Pdf.MarkdownStyleNames module defines all the names of styles used to format the different Markdown elements (e.g. heading 1-6, code block, listing 1-3, etc.) into PDF. To override the default styles, you need to:

1. Instantiate an instance of the Document type from the MigraDoc.DocumentObjectModel namespace.
2. Add the predefined style names from the aforementioned MarkdownStyleNames module to the document’s collection of styles.
3. Tweak the style to your liking.
4. Call the FSharp.Markdown.Pdf.PdfFormatting.formatMarkdown function with the Document value.
5. Voila! You now have an instance of PdfDocument which has been formatted with your custom styling.

to see these simple steps in action:

	open FSharp.Markdown
	open FSharp.Markdown.Pdf
	open MigraDoc.DocumentObjectModel
	let text = """Some text in Markdown format..."
	// you still have to parse the markdown document using the Markdown parser in the
	// FSharp.Markdown namespace
	let parsed = Markdown.Parse(markdownDoc)
	// but instead of using Markdown.WritePdf or Markdown.TransformPdf, you can set
	// override styles by instantiating an instance of the Document type from MigraDoc
	let doc = new Document()
	// you can set overrides for any styles used for formatting markdown elements, as defined in
	// the MarkdownStyleNames module, e.g. Quoted, Code, Heading1-6, etc.
	let quotedBlockStyle = doc.Styles.AddStyle(MarkdownStyleNames.Quoted, StyleNames.Normal)
	quotedBlockStyle.ParagraphFormat.Shading.Visible <- true
	quotedBlockStyle.ParagraphFormat.Shading.Color <- Colors.Black
	quotedBlockStyle.Font.Color <- Colors.White
	// the formatMarkdown function in the FSharp.Markdown.Pdf namespace takes the Document
	// value and returns an instance of PdfDocument which you can then save to local filesystem
	let pdfDoc = formatMarkdown doc parsed.DefinedLinks parsed.Paragraphs
	pdfDoc.Save @"C:\temp\markdown-customized.pdf"

view raw gistfile1.fs hosted with by GitHub

You can compare the original and customized PDF outputs here and here.