MathMarkdown

Approaches

• Use RegEx to preprocess Markdown text, and substitute math latex code that swift-markdown and cmark-gfm cannot handle by UUIDs.
• Apply swift-markdown parsing on the substituted text.
• Use MarkupWalker to extract the finalized list of network images, local images and math images that need to be generated.
• Use Async/Await to handle SwiftMathImage and Image download
• Embed Remote NSTextAttachment(iOS) and NSTextAttachmentCell(macOS) into NSAttributedString
• Build using a Formatter on NSAttributedString for PDF generation.
• Prepare for async notification to refresh NSTextAttachment or NSTextAttachmentCell.

Some Limitations

• objcio.attributed-string-builder (supports cocoa only, uses TextBlock), adopt its MarkupWalker approach,
• NSAttributedString, paragraphStyle implementation is different across cocoa and uikit. The former has TextBlock for Table.
• struct based MarkupVisitor and MarkupWalkers cannot be subclassed.
• NSImage, drawn using CoreGraphics preserves Glphy Infos while UIImage does not, end upwith awkward multi-line math equations across PDF pages.

References

• This does not depend on apple/swift-markdown https://github.com/objecthub/swift-markdownkit.git
• Renderer is publishing to SwiftUI only https://github.com/LiYanan2004/MarkdownView.git/Sources/MardownView/Renderer/Renderer.swift
• Other library to configure view on Markdown visitor, https://github.com/johnxnguyen/Down.git
• Unfortunately, this only supports MacOS but not iOS. https://github.com/objcio/attributed-string-builder.git
• apple/swift-docc/Sources/SwiftDocC/Model/Rendering/RenderContentCompiler use MarkupVisitor
• read StyleKit/StyleKit/Font.swift on Bundle handling https://github.com/nathantannar4/StyleKit.git .
• This is mainly cgContext based rendering, not even covering pdf, https://github.com/shaps80/GraphicsRenderer/tree/master
• Mainly for drawing stuff, use with GraphicsRenderer, https://github.com/shaps80/InkKit.git