rehype-callouts

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

What is this?

This plugin adds support for callouts (admonitions/alerts), allowing you to use Obsidian's callout syntax uniformly in markdown to achieve the following features:

• Includes default callout types for various themes.
• Optionally import stylesheets for corresponding themes.
• Supports collapsible callouts with -/+ and nestable callouts.
• Allows custom titles with markdown syntax.
• Customizable default callout types (title, icon, color).
• Configurable new callout types.
• Configurable aliases for callout types.
• Configurable icon display.

When should I use this?

This plugin helps render markdown callouts, making it ideal for displaying Obsidian callouts on an Astro-powered blog.

It also modifies HTML directly (no allowDangerousHtml in remark-rehype) and supports collapsible callouts using the details tag, all without 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
  dir="auto"
  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
  dir="auto"
  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 callout styles using the class names mentioned above or import the provided theme-specific stylesheets:

import 'rehype-callouts/theme/github'
import 'rehype-callouts/theme/obsidian'
import 'rehype-callouts/theme/vitepress'

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 render callouts, including an optional parameter options.

options: UserOptions

You can configure this plugin with the following optional settings:

Option	Type (default)	Description
theme	'github'|'obsidian'|'vitepress' (default: 'obsidian')	Specifies 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: {})	Configures aliases for callout types. For example: {'note': ['n'], 'tip': ['t']}
showIndicator	boolean(default: true)	Whether to display an type-specific icons before callout title.
htmlTagNames	HtmlTagNamesConfig(default: 'div')	Configures HTML tag names for elements within the callout structure for semantic flexibility.

callouts: Record<string, CalloutConfig>

Defines 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.

htmlTagNames: HtmlTagNamesConfig

Configures HTML tag names for elements within the callout structure for semantic flexibility. Note that custom HTML tag names may affect default package styling; check and adjust styles as needed.

Property	Type	Description
nonCollapsibleContainerTagName	string	Tag name for the outer container of non-collapsible callouts. For collapsible callouts, the tag name is fixed to details for functionality.
nonCollapsibleTitleTagName	string	Tag name for the title container of non-collapsible callouts. For collapsible callouts, the tag name is fixed to summary for functionality.
nonCollapsibleContentTagName	string	Tag name for the content container of non-collapsible callouts.
collapsibleContentTagName	string	Tag name for the content container of collapsible callouts.
iconTagName	string	Tag name for the icon container in both collapsible and non-collapsible callouts, including the fold icon in collapsible ones.
titleInnerTagName	string	Tag name for the inner container of the title text in both collapsible and non-collapsible callouts.

Themes

This package provides callout styles for GitHub, Obsidian, and VitePress, with dark mode support via the .dark class. For more, check the source code.

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