Overview

I created a simple document management tool to meet the demand for converting Markdown files to PDF.

I used existing libraries without much thought, so the structure doesn't feel very sustainable.

Motivation

If you just want to convert Markdown files to PDF, you can simply use a library called md-to-pdf.

This library is also helpful for managing resumes. cf. Managing Resumes on Github

I wanted to create something that supports mermaid notation and emojis not registered in unicode.

Using the vscode-markdown-pdf extension for VSCode can easily solve this, but it requires VSCode, which some people may need to install.

I thought using VSCode just for conversion was nonsensical, so I implemented it.

Design

The library md-to-pdf is easy to use and great, but it currently doesn't support the following features by default:

Mermaid notation
Emojis (other than those registered in unicode)
TOC generation

Since md-to-pdf allows configuration extensions with markedjs/marked, it seems possible to achieve these by customizing md-to-pdf.

There seems to be a plan to support TOC. Generate TOC (table of contents) #74

Although using md-to-pdf was an option, it seemed a bit cumbersome, so I wanted to implement it quickly like a hackathon and decided to use a library called md-to-pdf-ng.

This library extends md-to-pdf to support mermaid notation. It doesn't seem to be well-maintained, but it works without issues.

Based on md-to-pdf-ng, emoji support is achieved using node-emojify, and TOC generation is achieved using a library called doctoc.

Implementation

Install the following via npm:

Note: textlint is also included as a bonus, but that part is omitted.

Emoji support is handled by extending marked, so prepare a configuration file like this:

const marked = require('marked');
const { emojify } = require('node-emoji');

const renderer = new marked.Renderer();

renderer.text = emojify;

module.exports = {
	marked_options: { renderer },
};

Define the following command in the scripts section of package.json:

doctoc --notitle md/ && md-to-pdf md/*.md --config-file config.js && mv md/*.pdf pdf/

First, generate the TOC with doctoc, then convert Markdown to PDF, and finally move the directory.

It would be nice if the output destination of the pdf generated by md-to-pdf could be specified by directory, but since there doesn't seem to be such an option, I'm handling it with a straightforward method: mv md/*.pdf pdf/.

Thoughts

When trying to create something like this, you tend to rely heavily on external libraries. Ideally, I'd like to implement everything myself, but it seems quite challenging. If I get the chance, I'd like to learn about PDF data structures or create a similar CLI tool in Go.