544 lines
14 KiB
Markdown
544 lines
14 KiB
Markdown
# remark-directive
|
||
|
||
[![Build][build-badge]][build]
|
||
[![Coverage][coverage-badge]][coverage]
|
||
[![Downloads][downloads-badge]][downloads]
|
||
[![Size][size-badge]][size]
|
||
[![Sponsors][sponsors-badge]][collective]
|
||
[![Backers][backers-badge]][collective]
|
||
[![Chat][chat-badge]][chat]
|
||
|
||
**[remark][]** plugin to support the [generic directives
|
||
proposal][commonmark-prop] (`:cite[smith04]`,
|
||
`::youtube[Video of a cat in a box]{v=01ab2cd3efg}`, and such).
|
||
|
||
## Contents
|
||
|
||
* [What is this?](#what-is-this)
|
||
* [When should I use this?](#when-should-i-use-this)
|
||
* [Install](#install)
|
||
* [Use](#use)
|
||
* [API](#api)
|
||
* [`unified().use(remarkDirective[, options])`](#unifieduseremarkdirective-options)
|
||
* [`Options`](#options)
|
||
* [Examples](#examples)
|
||
* [Example: YouTube](#example-youtube)
|
||
* [Example: Styled blocks](#example-styled-blocks)
|
||
* [Authoring](#authoring)
|
||
* [HTML](#html)
|
||
* [CSS](#css)
|
||
* [Syntax](#syntax)
|
||
* [Syntax tree](#syntax-tree)
|
||
* [Types](#types)
|
||
* [Compatibility](#compatibility)
|
||
* [Security](#security)
|
||
* [Related](#related)
|
||
* [Contribute](#contribute)
|
||
* [License](#license)
|
||
|
||
## What is this?
|
||
|
||
This package is a [unified][] ([remark][]) plugin to add support for directives:
|
||
one syntax for arbitrary extensions in markdown.
|
||
|
||
## When should I use this?
|
||
|
||
Directives are one of the four ways to extend markdown: an arbitrary extension
|
||
syntax (see [Extending markdown][micromark-extending-markdown] in micromark’s
|
||
docs for the alternatives and more info).
|
||
This mechanism works well when you control the content: who authors it, what
|
||
tools handle it, and where it’s displayed.
|
||
When authors can read a guide on how to embed a tweet but are not expected to
|
||
know the ins and outs of HTML or JavaScript.
|
||
Directives don’t work well if you don’t know who authors content, what tools
|
||
handle it, and where it ends up.
|
||
Example use cases are a docs website for a project or product, or blogging
|
||
tools and static site generators.
|
||
|
||
If you *just* want to turn markdown into HTML (with maybe a few extensions such
|
||
as this one), we recommend [`micromark`][micromark] with
|
||
[`micromark-extension-directive`][micromark-extension-directive] instead.
|
||
If you don’t use plugins and want to access the syntax tree, you can use
|
||
[`mdast-util-from-markdown`][mdast-util-from-markdown] with
|
||
[`mdast-util-directive`][mdast-util-directive].
|
||
|
||
## Install
|
||
|
||
This package is [ESM only][esm].
|
||
In Node.js (version 16+), install with [npm][]:
|
||
|
||
```sh
|
||
npm install remark-directive
|
||
```
|
||
|
||
In Deno with [`esm.sh`][esmsh]:
|
||
|
||
```js
|
||
import remarkDirective from 'https://esm.sh/remark-directive@3'
|
||
```
|
||
|
||
In browsers with [`esm.sh`][esmsh]:
|
||
|
||
```html
|
||
<script type="module">
|
||
import remarkDirective from 'https://esm.sh/remark-directive@3?bundle'
|
||
</script>
|
||
```
|
||
|
||
## Use
|
||
|
||
Say our document `example.md` contains:
|
||
|
||
```markdown
|
||
:::main{#readme}
|
||
|
||
Lorem:br
|
||
ipsum.
|
||
|
||
::hr{.red}
|
||
|
||
A :i[lovely] language know as :abbr[HTML]{title="HyperText Markup Language"}.
|
||
|
||
:::
|
||
```
|
||
|
||
…and our module `example.js` contains:
|
||
|
||
```js
|
||
/**
|
||
* @import {} from 'mdast-util-directive'
|
||
* @import {} from 'mdast-util-to-hast'
|
||
* @import {Root} from 'mdast'
|
||
*/
|
||
|
||
import {h} from 'hastscript'
|
||
import rehypeFormat from 'rehype-format'
|
||
import rehypeStringify from 'rehype-stringify'
|
||
import remarkDirective from 'remark-directive'
|
||
import remarkParse from 'remark-parse'
|
||
import remarkRehype from 'remark-rehype'
|
||
import {read} from 'to-vfile'
|
||
import {unified} from 'unified'
|
||
import {visit} from 'unist-util-visit'
|
||
|
||
const file = await unified()
|
||
.use(remarkParse)
|
||
.use(remarkDirective)
|
||
.use(myRemarkPlugin)
|
||
.use(remarkRehype)
|
||
.use(rehypeFormat)
|
||
.use(rehypeStringify)
|
||
.process(await read('example.md'))
|
||
|
||
console.log(String(file))
|
||
|
||
// This plugin is an example to let users write HTML with directives.
|
||
// It’s informative but rather useless.
|
||
// See below for others examples.
|
||
function myRemarkPlugin() {
|
||
/**
|
||
* @param {Root} tree
|
||
* Tree.
|
||
* @returns {undefined}
|
||
* Nothing.
|
||
*/
|
||
return function (tree) {
|
||
visit(tree, function (node) {
|
||
if (
|
||
node.type === 'containerDirective' ||
|
||
node.type === 'leafDirective' ||
|
||
node.type === 'textDirective'
|
||
) {
|
||
const data = node.data || (node.data = {})
|
||
const hast = h(node.name, node.attributes || {})
|
||
|
||
data.hName = hast.tagName
|
||
data.hProperties = hast.properties
|
||
}
|
||
})
|
||
}
|
||
}
|
||
```
|
||
|
||
…then running `node example.js` yields:
|
||
|
||
```html
|
||
<main id="readme">
|
||
<p>Lorem<br>ipsum.</p>
|
||
<hr class="red">
|
||
<p>A <i>lovely</i> language know as <abbr title="HyperText Markup Language">HTML</abbr>.</p>
|
||
</main>
|
||
```
|
||
|
||
## API
|
||
|
||
This package exports no identifiers.
|
||
The default export is [`remarkDirective`][api-remark-directive].
|
||
|
||
### `unified().use(remarkDirective[, options])`
|
||
|
||
Add support for generic directives.
|
||
|
||
###### Parameters
|
||
|
||
* `options` ([`Options`][api-options], optional)
|
||
— configuration
|
||
|
||
###### Returns
|
||
|
||
Nothing (`undefined`).
|
||
|
||
###### Notes
|
||
|
||
Doesn’t handle the directives:
|
||
[create your own plugin][unified-create-plugin] to do that.
|
||
|
||
### `Options`
|
||
|
||
Configuration (TypeScript type).
|
||
|
||
###### Fields
|
||
|
||
* `collapseEmptyAttributes`
|
||
(`boolean`, default: `true`)
|
||
— collapse empty attributes: get `title` instead of `title=""`
|
||
* `preferShortcut`
|
||
(`boolean`, default: `true`)
|
||
— prefer `#` and `.` shortcuts for `id` and `class`
|
||
* `preferUnquoted`
|
||
(`boolean`, default: `false`)
|
||
— leave attributes unquoted if that results in less bytes
|
||
* `quoteSmart`
|
||
(`boolean`, default: `false`)
|
||
— use the other quote if that results in less bytes
|
||
* `quote`
|
||
(`'"'` or `"'"`,
|
||
default: the [`quote`][quote] used by `remark-stringify` for titles)
|
||
— preferred quote to use around attribute values
|
||
|
||
## Examples
|
||
|
||
### Example: YouTube
|
||
|
||
This example shows how directives can be used for YouTube embeds.
|
||
It’s based on the example in Use above.
|
||
If `myRemarkPlugin` was replaced with this function:
|
||
|
||
```js
|
||
/**
|
||
* @import {} from 'mdast-util-directive'
|
||
* @import {} from 'mdast-util-to-hast'
|
||
* @import {Root} from 'mdast'
|
||
* @import {VFile} from 'vfile'
|
||
*/
|
||
|
||
import {visit} from 'unist-util-visit'
|
||
|
||
// This plugin is an example to turn `::youtube` into iframes.
|
||
function myRemarkPlugin() {
|
||
/**
|
||
* @param {Root} tree
|
||
* Tree.
|
||
* @param {VFile} file
|
||
* File.
|
||
* @returns {undefined}
|
||
* Nothing.
|
||
*/
|
||
return (tree, file) => {
|
||
visit(tree, function (node) {
|
||
if (
|
||
node.type === 'containerDirective' ||
|
||
node.type === 'leafDirective' ||
|
||
node.type === 'textDirective'
|
||
) {
|
||
if (node.name !== 'youtube') return
|
||
|
||
const data = node.data || (node.data = {})
|
||
const attributes = node.attributes || {}
|
||
const id = attributes.id
|
||
|
||
if (node.type === 'textDirective') {
|
||
file.fail(
|
||
'Unexpected `:youtube` text directive, use two colons for a leaf directive',
|
||
node
|
||
)
|
||
}
|
||
|
||
if (!id) {
|
||
file.fail('Unexpected missing `id` on `youtube` directive', node)
|
||
}
|
||
|
||
data.hName = 'iframe'
|
||
data.hProperties = {
|
||
src: 'https://www.youtube.com/embed/' + id,
|
||
width: 200,
|
||
height: 200,
|
||
frameBorder: 0,
|
||
allow: 'picture-in-picture',
|
||
allowFullScreen: true
|
||
}
|
||
}
|
||
})
|
||
}
|
||
}
|
||
```
|
||
|
||
…and `example.md` contains:
|
||
|
||
```markdown
|
||
# Cat videos
|
||
|
||
::youtube[Video of a cat in a box]{#01ab2cd3efg}
|
||
```
|
||
|
||
…then running `node example.js` yields:
|
||
|
||
```html
|
||
<h1>Cat videos</h1>
|
||
<iframe src="https://www.youtube.com/embed/01ab2cd3efg" width="200" height="200" frameborder="0" allow="picture-in-picture" allowfullscreen>Video of a cat in a box</iframe>
|
||
```
|
||
|
||
### Example: Styled blocks
|
||
|
||
> 👉 **Note**: This is sometimes called admonitions, callouts, etc.
|
||
|
||
This example shows how directives can be used to style blocks.
|
||
It’s based on the example in Use above.
|
||
If `myRemarkPlugin` was replaced with this function:
|
||
|
||
```js
|
||
/**
|
||
* @import {} from 'mdast-util-directive'
|
||
* @import {} from 'mdast-util-to-hast'
|
||
* @import {Root} from 'mdast'
|
||
*/
|
||
|
||
import {h} from 'hastscript'
|
||
import {visit} from 'unist-util-visit'
|
||
|
||
// This plugin is an example to turn `::note` into divs, passing arbitrary
|
||
// attributes.
|
||
function myRemarkPlugin() {
|
||
/**
|
||
* @param {Root} tree
|
||
* Tree.
|
||
* @returns {undefined}
|
||
* Nothing.
|
||
*/
|
||
return (tree) => {
|
||
visit(tree, (node) => {
|
||
if (
|
||
node.type === 'containerDirective' ||
|
||
node.type === 'leafDirective' ||
|
||
node.type === 'textDirective'
|
||
) {
|
||
if (node.name !== 'note') return
|
||
|
||
const data = node.data || (node.data = {})
|
||
const tagName = node.type === 'textDirective' ? 'span' : 'div'
|
||
|
||
data.hName = tagName
|
||
data.hProperties = h(tagName, node.attributes || {}).properties
|
||
}
|
||
})
|
||
}
|
||
}
|
||
```
|
||
|
||
…and `example.md` contains:
|
||
|
||
```markdown
|
||
# How to use xxx
|
||
|
||
You can use xxx.
|
||
|
||
:::note{.warning}
|
||
if you chose xxx, you should also use yyy somewhere…
|
||
:::
|
||
```
|
||
|
||
…then running `node example` yields:
|
||
|
||
```html
|
||
<h1>How to use xxx</h1>
|
||
<p>You can use xxx.</p>
|
||
<div class="warning">
|
||
<p>if you chose xxx, you should also use yyy somewhere…</p>
|
||
</div>
|
||
```
|
||
|
||
## Authoring
|
||
|
||
When authoring markdown with directives, keep in mind that they don’t work in
|
||
most places.
|
||
On your own site it can be great!
|
||
|
||
## HTML
|
||
|
||
You can define how directives are turned into HTML.
|
||
If directives are not handled, they do not emit anything.
|
||
|
||
## CSS
|
||
|
||
How to display directives is left as an exercise for the reader.
|
||
|
||
## Syntax
|
||
|
||
See [*Syntax* in
|
||
`micromark-extension-directive`](https://github.com/micromark/micromark-extension-directive#syntax).
|
||
|
||
## Syntax tree
|
||
|
||
See [*Syntax tree* in
|
||
`mdast-util-directive`](https://github.com/syntax-tree/mdast-util-directive#syntax-tree).
|
||
|
||
## Types
|
||
|
||
This package is fully typed with [TypeScript][].
|
||
It exports no additional options.
|
||
|
||
If you’re working with the syntax tree, you can register the new node types
|
||
with `@types/mdast` by adding a reference:
|
||
|
||
```js
|
||
/**
|
||
* @import {} from 'mdast-util-directive'
|
||
* @import {Root} from 'mdast'
|
||
*/
|
||
|
||
import {visit} from 'unist-util-visit'
|
||
|
||
function myRemarkPlugin() {
|
||
/**
|
||
* @param {Root} tree
|
||
* Tree.
|
||
* @returns {undefined}
|
||
* Nothing.
|
||
*/
|
||
return (tree) => {
|
||
visit(tree, function (node) {
|
||
console.log(node) // `node` can now be one of the nodes for directives.
|
||
})
|
||
}
|
||
}
|
||
```
|
||
|
||
## Compatibility
|
||
|
||
Projects maintained by the unified collective are compatible with maintained
|
||
versions of Node.js.
|
||
|
||
When we cut a new major release, we drop support for unmaintained versions of
|
||
Node.
|
||
This means we try to keep the current release line, `remark-directive@^3`,
|
||
compatible with Node.js 16.
|
||
|
||
## Security
|
||
|
||
Use of `remark-directive` does not involve **[rehype][]** ([hast][]) or user
|
||
content so there are no openings for [cross-site scripting (XSS)][wiki-xss]
|
||
attacks.
|
||
|
||
## Related
|
||
|
||
* [`remark-gfm`](https://github.com/remarkjs/remark-gfm)
|
||
— support GFM (autolink literals, footnotes, strikethrough, tables,
|
||
tasklists)
|
||
* [`remark-frontmatter`](https://github.com/remarkjs/remark-frontmatter)
|
||
— support frontmatter (YAML, TOML, and more)
|
||
* [`remark-math`](https://github.com/remarkjs/remark-math)
|
||
— support math
|
||
* [`remark-mdx`](https://github.com/mdx-js/mdx/tree/main/packages/remark-mdx)
|
||
— support MDX (ESM, JSX, expressions)
|
||
|
||
## Contribute
|
||
|
||
See [`contributing.md`][contributing] in [`remarkjs/.github`][health] for ways
|
||
to get started.
|
||
See [`support.md`][support] for ways to get help.
|
||
|
||
This project has a [code of conduct][coc].
|
||
By interacting with this repository, organization, or community you agree to
|
||
abide by its terms.
|
||
|
||
## License
|
||
|
||
[MIT][license] © [Titus Wormer][author]
|
||
|
||
<!-- Definitions -->
|
||
|
||
[build-badge]: https://github.com/remarkjs/remark-directive/workflows/main/badge.svg
|
||
|
||
[build]: https://github.com/remarkjs/remark-directive/actions
|
||
|
||
[coverage-badge]: https://img.shields.io/codecov/c/github/remarkjs/remark-directive.svg
|
||
|
||
[coverage]: https://codecov.io/github/remarkjs/remark-directive
|
||
|
||
[downloads-badge]: https://img.shields.io/npm/dm/remark-directive.svg
|
||
|
||
[downloads]: https://www.npmjs.com/package/remark-directive
|
||
|
||
[size-badge]: https://img.shields.io/bundlejs/size/remark-directive
|
||
|
||
[size]: https://bundlejs.com/?q=remark-directive
|
||
|
||
[sponsors-badge]: https://opencollective.com/unified/sponsors/badge.svg
|
||
|
||
[backers-badge]: https://opencollective.com/unified/backers/badge.svg
|
||
|
||
[collective]: https://opencollective.com/unified
|
||
|
||
[chat-badge]: https://img.shields.io/badge/chat-discussions-success.svg
|
||
|
||
[chat]: https://github.com/remarkjs/remark/discussions
|
||
|
||
[npm]: https://docs.npmjs.com/cli/install
|
||
|
||
[esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c
|
||
|
||
[esmsh]: https://esm.sh
|
||
|
||
[health]: https://github.com/remarkjs/.github
|
||
|
||
[contributing]: https://github.com/remarkjs/.github/blob/main/contributing.md
|
||
|
||
[support]: https://github.com/remarkjs/.github/blob/main/support.md
|
||
|
||
[coc]: https://github.com/remarkjs/.github/blob/main/code-of-conduct.md
|
||
|
||
[license]: license
|
||
|
||
[author]: https://wooorm.com
|
||
|
||
[commonmark-prop]: https://talk.commonmark.org/t/generic-directives-plugins-syntax/444
|
||
|
||
[hast]: https://github.com/syntax-tree/hast
|
||
|
||
[mdast-util-directive]: https://github.com/syntax-tree/mdast-util-directive
|
||
|
||
[mdast-util-from-markdown]: https://github.com/syntax-tree/mdast-util-from-markdown
|
||
|
||
[micromark]: https://github.com/micromark/micromark
|
||
|
||
[micromark-extension-directive]: https://github.com/micromark/micromark-extension-directive
|
||
|
||
[micromark-extending-markdown]: https://github.com/micromark/micromark#extending-markdown
|
||
|
||
[quote]: https://github.com/remarkjs/remark/tree/main/packages/remark-stringify#options
|
||
|
||
[rehype]: https://github.com/rehypejs/rehype
|
||
|
||
[remark]: https://github.com/remarkjs/remark
|
||
|
||
[typescript]: https://www.typescriptlang.org
|
||
|
||
[unified]: https://github.com/unifiedjs/unified
|
||
|
||
[unified-create-plugin]: https://unifiedjs.com/learn/guide/create-a-plugin/
|
||
|
||
[wiki-xss]: https://en.wikipedia.org/wiki/Cross-site_scripting
|
||
|
||
[api-remark-directive]: #unifieduseremarkdirective-options
|
||
|
||
[api-options]: #options
|