mdast-util-directive

What is mdast-util-directive?

The `mdast-util-directive` package is a utility for working with directives in Markdown Abstract Syntax Trees (MDAST). It allows you to parse, transform, and stringify custom directives in Markdown documents, enabling more advanced and customizable Markdown processing.

What are mdast-util-directive's main functionalities?

Parsing Directives

This feature allows you to parse custom directives in Markdown content into an MDAST. The code sample demonstrates how to set up a processor with `remark-parse` and `mdast-util-directive` to parse a custom directive.

const { fromMarkdown } = require('mdast-util-directive');
const { unified } = require('unified');
const markdown = require('remark-parse');

const processor = unified()
  .use(markdown)
  .use(fromMarkdown);

const mdContent = ':::{.example}
This is a custom directive
:::';

const tree = processor.parse(mdContent);
console.log(tree);

Transforming Directives

This feature allows you to transform custom directives in the MDAST. The code sample shows how to use `unist-util-visit` to visit and transform a custom directive node in the syntax tree.

const { visit } = require('unist-util-visit');
const { fromMarkdown } = require('mdast-util-directive');
const { unified } = require('unified');
const markdown = require('remark-parse');

const processor = unified()
  .use(markdown)
  .use(fromMarkdown);

const mdContent = ':::{.example}
This is a custom directive
:::';

const tree = processor.parse(mdContent);

visit(tree, 'containerDirective', (node) => {
  node.data = { hName: 'div', hProperties: { className: 'example' } };
});

console.log(tree);

Stringifying Directives

This feature allows you to stringify custom directives back into Markdown. The code sample demonstrates how to set up a processor to parse and then stringify a custom directive.

const { toMarkdown } = require('mdast-util-directive');
const { unified } = require('unified');
const markdown = require('remark-parse');
const stringify = require('remark-stringify');

const processor = unified()
  .use(markdown)
  .use(fromMarkdown)
  .use(stringify)
  .use(toMarkdown);

const mdContent = ':::{.example}
This is a custom directive
:::';

const tree = processor.parse(mdContent);
const output = processor.stringify(tree);
console.log(output);

Other packages similar to mdast-util-directive

remark-directive

The `remark-directive` package is a plugin for `remark` that provides support for parsing and transforming directives in Markdown. It is similar to `mdast-util-directive` but is specifically designed to work within the `remark` ecosystem, providing a more integrated experience for users of `remark`.

remark-custom-blocks

The `remark-custom-blocks` package allows you to define custom block-level elements in Markdown. It is similar to `mdast-util-directive` in that it provides a way to extend Markdown with custom syntax, but it focuses specifically on block-level elements and their transformations.

remark-shortcodes

The `remark-shortcodes` package enables the use of shortcode syntax in Markdown documents. It is similar to `mdast-util-directive` in that it allows for custom syntax extensions, but it uses a different approach with shortcode-like syntax rather than directive syntax.

README

mdast-util-directive

Extension for mdast-util-from-markdown and/or mdast-util-to-markdown to support the generic directives proposal (:cite[smith04], ::youtube[Video of a cat in a box]{v=01ab2cd3efg}, and such) in mdast. When parsing (from-markdown), must be combined with micromark-extension-directive.

See micromark-extension-directive for how the syntax works. This utility handles parsing and serializing. Traverse the tree to change them to whatever you please.

When to use this

Use this if you’re dealing with the AST manually. It might be better to use remark-directive with remark, which includes this but provides a nicer interface and makes it easier to combine with hundreds of plugins.

Install

This package is ESM only: Node 12+ is needed to use it and it must be imported instead of required.

npm:

npm install mdast-util-directive

Use

Say our module, example.js, looks as follows:

import {fromMarkdown} from 'mdast-util-from-markdown'
import {toMarkdown} from 'mdast-util-to-markdown'
import {directive} from 'micromark-extension-directive'
import {directiveFromMarkdown, directiveToMarkdown} from 'mdast-util-directive'

const doc = 'A lovely language know as :abbr[HTML]{title="HyperText Markup Language"}.'

const tree = fromMarkdown(doc, {
  extensions: [directive()],
  mdastExtensions: [directiveFromMarkdown]
})

console.log(tree)

const out = toMarkdown(tree, {extensions: [directiveToMarkdown]})

console.log(out)

Now, running node example yields (positional info removed for brevity):

{
  type: 'root',
  children: [
    {
      type: 'paragraph',
      children: [
        {type: 'text', value: 'A lovely language know as '},
        {
          type: 'textDirective',
          name: 'abbr',
          attributes: {title: 'HyperText Markup Language'},
          children: [{type: 'text', value: 'HTML'}]
        },
        {type: 'text', value: '.'}
      ]
    }
  ]
}

A lovely language know as :abbr[HTML]{title="HyperText Markup Language"}.

API

directiveFromMarkdown

directiveToMarkdown

Support the generic directives proposal. The exports are extensions, respectively for mdast-util-from-markdown and mdast-util-to-markdown.

There are no options, but passing options.quote to mdast-util-to-markdown is honored for attributes.

This utility handles parsing and serializing. Traverse the tree to change them to whatever you please.

Syntax tree

The following interfaces are added to mdast by this utility.

Nodes

TextDirective

interface TextDirective <: Parent {
  type: 'textDirective'
  children: [PhrasingContent]
}

TextDirective includes Directive

TextDirective (Parent) is a directive. It can be used where phrasing content is expected. Its content model is also phrasing content. It includes the mixin Directive.

For example, the following Markdown:

:name[Label]{#x.y.z key=value}

Yields:

{
  type: 'textDirective',
  name: 'name',
  attributes: {id: 'x', class: 'y z', key: 'value'},
  children: [{type: 'text', value: 'Label'}]
}

LeafDirective

interface LeafDirective <: Parent {
  type: 'leafDirective'
  children: [PhrasingContent]
}

LeafDirective includes Directive

LeafDirective (Parent) is a directive. It can be used where flow content is expected. Its content model is phrasing content. It includes the mixin Directive.

For example, the following Markdown:

::youtube[Label]{v=123}

Yields:

{
  type: 'leafDirective',
  name: 'youtube',
  attributes: {v: '123'},
  children: [{type: 'text', value: 'Label'}]
}

ContainerDirective

interface ContainerDirective <: Parent {
  type: 'containerDirective'
  children: [FlowContent]
}

ContainerDirective includes Directive

ContainerDirective (Parent) is a directive. It can be used where flow content is expected. Its content model is also flow content. It includes the mixin Directive.

The phrasing in the label is, when available, added as a paragraph with a directiveLabel: true field, as the head of its content.

For example, the following Markdown:

:::spoiler[Open at your own peril]
He dies.
:::

Yields:

{
  type: 'containerDirective',
  name: 'spoiler',
  attributes: {},
  children: [
    {
      type: 'paragraph',
      data: {directiveLabel: true},
      children: [{type: 'text', value: 'Open at your own peril'}]
    },
    {
      type: 'paragraph',
      children: [{type: 'text', value: 'He dies.'}]
    }
  ]
}

Mixin

Directive

interface mixin Directive {
  name: string
  attributes: Attributes?
}

interface Attributes {}
typedef string AttributeName
typedef string AttributeValue

Directive represents something defined by an extension.

The name field must be present and represents an identifier of an extension.

The attributes field represents information associated with the node. The value of the attributes field implements the Attributes interface.

In the Attributes interface, every field must be an AttributeName and every value an AttributeValue. The fields and values can be anything: there are no semantics (such as by HTML or hast).

In JSON, the value null must be treated as if the attribute was not included. In JavaScript, both null and undefined must be similarly ignored.

Related

• remarkjs/remark — markdown processor powered by plugins
• remarkjs/remark-directive — remark plugin to support generic directives
• micromark/micromark — the smallest commonmark-compliant markdown parser that exists
• micromark/micromark-extension-directive — micromark extension to parse directives
• syntax-tree/mdast-util-from-markdown — mdast parser using micromark to create mdast from markdown
• syntax-tree/mdast-util-to-markdown — mdast serializer to create markdown from mdast

Contribute

See contributing.md in syntax-tree/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organization, or community you agree to abide by its terms.

License

MIT © Titus Wormer