remark-d2

A remark plugin that turns d2 code blocks into diagrams in Markdown files.

https://github.com/mech-a/remark-d2/assets/11798509/e6c6276f-8839-46af-b29e-243f31cdce24

Features

Fast resizing and titling: metadata tags like width, position, and title are compiled:

      ┎─────── abbrev. ───────┒
```d2 w=150px;position=center;a="test"
d2->is->fast
```

becomes:

<img alt="test" position="center" width="150px" src="/d2/docs/features/0.svg" />

• width, w
• height, h
• position, p
• title, t
• alt, a

Change default d2 compile settings and default image attributes easily

const output = await remark()
  .use(remarkD2, {
    defaultD2Opts: ["-t 101", "--dark-theme 200"],
    //            "Orange Creamsicle" on light mode,
    //               "Dark Mauve" on dark mode
    defaultImageAttrs: {
      title: "Wow, colors!",
      alt: "Colorful Diagram",
      width: "700px",
    },
  })

  .processSync(file);

gets you

Try changing color modes and see!

Installation

Ensure that you have d2 installed and accessible on your PATH. Then, install using your favorite package manager:

npm install remark-d2

Usage

In your unified or remark toolchain, you can include the plugin. Note that the VFile passed in must have a path.

import { remark } from "remark";
import remarkD2 from "remark-d2";
import { VFile } from "vfile";
import { readFileSync } from "node:fs";

const file = new VFile({
  path: "docs/intro.md",
  value: readFileSync("docs/intro.md"),
});

const output = await remark().use(remarkD2).processSync(file);

console.log(output.toString());

Integrations

remark-d2 is compatible with Docusaurus out of the box. However, as Docusaurus does not currently support ES Modules, to install remark-d2 follow the workaround mentioned in the Docusaurus docs:

// in `docusaurus.config.js`

// wrap your config in a function:
async function createConfig() {
  // import the plugin here
  const d2 = (await import("remark-d2")).default;
  // return your config
  return {
    title: ...,
    tagline: ...,
    presets: [ // install here or in plugin config
      [
        '@docusaurus/preset-classic', // or any other preset
        {
          docs: {
            remarkPlugins; [d2], // works out of the box
          },
        },
      ],
    ],
  }
};

// export the function (will be automatically called)
module.exports = createConfig

Configuration

Options can be passed in as a parameter in .use. They should be in an Object form.

• compilePath
  • Relative path where d2 diagrams are exported in respective folders
  • default: static/d2, compatible with Docusaurus
• ext
  • File extension for d2 diagrams: currently only svg or png
    • Note that png is slower and does not support automatic light/dark mode
  • default: svg
• linkPath
  • Path prepended to the relative file path in the image URL
    • Useful if your build system removes the parent folder reference assets/ or static/
  • default: /d2, compatible with Docusaurus
• defaultD2Opts
  • Options passed to d2 CLI. See man d2 for more.
  • default: ["-t=100", "--dark-theme=200"]
• htmlImage
  • If true, replace all code blocks with HTML <img /> tags instead of Markdown images
    • If a code block has metadata, regardless of htmlImage's value, it will be an HTML image
  • default: false
• defaultImageAttrs
  • Default attributes for images
    • Only the keys title and alt apply to both Markdown and HTML images. All other attributes are only used if it is an HTML image.
  • default: { alt: "d2 diagram" }

Inspiration

remark-simple-plantuml