rehype-callouts

A rehype plugin for processing and rendering blockquote-based callouts.

What is this?

This package is a unified (rehype) plugin to add support for callouts (admonitions/alerts). This lets you to uniformly use Obsidian's callout syntax in markdown to achieve the following features:

• Comes with default callouts types.
• Supports custom titles (using markdown syntax).
• Supports collapsible and nestable callouts.
• Supports modifying default callouts (title, icon, color).
• Configurable themes for applying default callout types and styles.
• Configurable new types of callouts.
• Configurable aliases for callout types.
• Configurable icon display.

When should I use this?

This plugin is useful when you need to write callouts in markdown and render them effectively, such as displaying callouts written in Obsidian on a blog website created with the Astro framework.

Additionally, this plugin modifies HTML directly (no allowDangerousHtml needed in remark-rehype), and manages collapsible callouts using the details tag without requiring JavaScript.

Installation

This package is ESM only. In Node.js (version 16+), install with your package manager:

npm install rehype-callouts
yarn add rehype-callouts
pnpm add rehype-callouts

In Deno with esm.sh:

import rehypeCallouts from 'https://esm.sh/rehype-callouts'

In browsers with esm.sh:

<script type="module">
  import rehypeCallouts from 'https://esm.sh/rehype-callouts?bundle'
</script>

Usage

Say example.md contains:

<!-- Callout type names are case-insensitive: 'Note', 'NOTE', and 'note' are equivalent. -->

> [!note] This is a _non-collapsible_ callout
> Some content is displayed directly!

> [!WARNING]- This is a **collapsible** callout
> Some content shown after opening!

And module example.js contains:

import { unified } from 'unified'
import remarkParse from 'remark-parse'
import remarkRehype from 'remark-rehype'
import rehypeCallouts from 'rehype-callouts'
import rehypeStringify from 'rehype-stringify'
import { readSync } from 'to-vfile'

const file = unified()
  .use(remarkParse)
  .use(remarkRehype)
  .use(rehypeCallouts)
  .use(rehypeStringify)
  .processSync(readSync('example.md'))

console.log(String(file))

Or for an Astro project, the astro.config.ts contains:

import { defineConfig } from 'astro/config'
import rehypeCallouts from 'rehype-callouts'

// https://docs.astro.build/en/reference/configuration-reference/
export default defineConfig({
  // ...
  markdown: {
    // ...
    rehypePlugins: [
      // ...
      rehypeCallouts,
    ],
  },
  // ...
})

Then running node example.js or pnpm astro dev yields:

<div
  class="callout"
  style="--callout-color-light: rgb(8, 109, 221); --callout-color-dark: rgb(2, 122, 255);"
>
  <div class="callout-title">
    <div class="callout-icon">
      <!-- svg icon-->
    </div>
    <div class="callout-title-inner">
      This is a <em>non-collapsible</em> callout
    </div>
  </div>
  <div class="callout-content">
    <p>Some content is displayed directly!</p>
  </div>
</div>

<details
  class="callout callout-collapsible"
  style="--callout-color-light: rgb(236, 117, 0); --callout-color-dark: rgb(233, 151, 63);"
>
  <summary class="callout-title">
    <div class="callout-icon">
      <!-- svg icon-->
    </div>
    <div class="callout-title-inner">
      This is a <strong>collapsible</strong> callout
    </div>
    <div class="callout-fold">
      <!-- svg icon-->
    </div>
  </summary>
  <div class="callout-content">
    <p>Some content shown after opening!</p>
  </div>
</details>

Styling

You can customize the callout styles based on the class names (as shown above) or import the stylesheets for different themes provided by the package:

import 'rehype-callouts/theme/github'
import 'rehype-callouts/theme/obsidian'
import 'rehype-callouts/theme/vitepress'
// or using URL import
import 'https://unpkg.com/rehype-callouts/themes/github/index.css'

If bundling CSS files, import the CSS in your main CSS file:

@import 'rehype-callouts/theme/github';

For Sass, import the CSS in your main Sass file:

@use 'rehype-callouts/theme/github';

Alternatively, import the CSS directly in browsers via unpkg.com or jsdelivr.net:

<link
  rel="stylesheet"
  href="https://unpkg.com/rehype-callouts/dist/themes/github/index.css"
/>
<link
  rel="stylesheet"
  href="https://cdn.jsdelivr.net/npm/rehype-callouts/dist/themes/github/index.css"
/>

API

This package exports no identifiers. The default export is rehypeCallouts.

unified().use(rehypeCallouts, options?)

Used to process and render callouts, including an optional parameter options.

options: UserOptions

Configure the behavior of this plugin using the following options. All of these options are optional:

Option	Type	Description
theme	'github'|'obsidian'|'vitepress' (default: obsidian)	Specify your desired callout theme to automatically apply its default callout types.
callouts	Record<string, CalloutConfig> (default: see source code )	Defines the properties for default and custom callouts. For example: {'note': {title: 'CustomTitle'}, 'custom': {color: 'pink'}}
aliases	Record<string, string[]> (default: {})	Configure aliases for callout types. For example: {'note': ['n'], 'tip': ['t']}
showIndicator	boolean(default: true)	Whether to display an type-specific icons before callout title.

callouts: Record<string, CalloutConfig>

Defines the properties for default and custom callouts. Each key represents a callout type, and the value is an object with the following optional properties:

Property	Type	Description
title	string	Title for this callout type. For new callout types, defaults to the callout type name if unset.
indicator	string	Icon in SVG format as a string. For new callout types, the icon will not display unless set, even if showIndicator is true. You can get icons from Iconify. For example: '<svg>...</svg>'
color	string | [string, string]	Color(s) as a <color> string. For new callout types, defaults to #888 if unset. For example: 'rgb(8, 109, 221)': works for both light and dark themes. ['#0969da', '#2f81f7'] : first for light theme, second for dark theme.

Themes

This package also provides callout styles for GitHub, Obsidian, and VitePress themes. These stylesheets implement dark mode using the .dark class. See the source code for more details.

GitHub

Obsidian

VitePress

Types

This package is fully typed with TypeScript. See jsDocs.io for type details.

Credits

• staticnoise/rehype-obsidian-callout - basic functionality.
• Octions - default icons for GitHub callouts.
• Lucide - default icons for Obsidian, VitePress callouts.

Contribution

If you see any errors or room for improvement on this plugin, feel free to open an issues or pull request . Thank you in advance for contributing!

License

MIT © 2024-PRESENT Stephanie Lin