mdast extension to parse and serialize MDX or MDX.js JSX
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[mdast][] extensions to parse and serialize [MDX][] JSX ().
* What is this?
* When to use this
* Install
* Use
* API
* mdxJsxFromMarkdown()
* mdxJsxToMarkdown(options?)
* MdxJsxAttribute
* MdxJsxAttributeValueExpression
* MdxJsxExpressionAttribute
* MdxJsxFlowElement
* MdxJsxFlowElementHast
* MdxJsxTextElement
* MdxJsxTextElementHast
* ToMarkdownOptions
* HTML
* Syntax
* Syntax tree
* Nodes
* Mixin
* Content model
* Types
* Compatibility
* Related
* Contribute
* License
This package contains two extensions that add support for MDX JSX syntax in
markdown to [mdast][].
These extensions plug into
[mdast-util-from-markdown][mdast-util-from-markdown] (to support parsing
JSX in markdown into a syntax tree) and
[mdast-util-to-markdown][mdast-util-to-markdown] (to support serializing
JSX in syntax trees to markdown).
[JSX][] is an XML-like syntax extension to ECMAScript (JavaScript), which MDX
brings to markdown.
For more info on MDX, see [What is MDX?][what-is-mdx]
You can use these extensions when you are working withmdast-util-from-markdown and mdast-util-to-markdown already.
When working with mdast-util-from-markdown, you must combine this package
with [micromark-extension-mdx-jsx][micromark-extension-mdx-jsx].
When you are working with syntax trees and want all of MDX, use
[mdast-util-mdx][mdast-util-mdx] instead.
All these packages are used in [remark-mdx][remark-mdx], which
focusses on making it easier to transform content by abstracting these
internals away.
This package is [ESM only][esm].
In Node.js (version 16+), install with [npm][]:
``sh`
npm install mdast-util-mdx-jsx
In Deno with [esm.sh][esmsh]:
`js`
import {mdxJsxFromMarkdown, mdxJsxToMarkdown} from 'https://esm.sh/mdast-util-mdx-jsx@3'
In browsers with [esm.sh][esmsh]:
`html`
Say our document example.mdx contains:
`mdx
- a list
HTML is a lovely language.
`
…and our module example.js looks as follows:
`js
import fs from 'node:fs/promises'
import * as acorn from 'acorn'
import {mdxJsx} from 'micromark-extension-mdx-jsx'
import {fromMarkdown} from 'mdast-util-from-markdown'
import {mdxJsxFromMarkdown, mdxJsxToMarkdown} from 'mdast-util-mdx-jsx'
import {toMarkdown} from 'mdast-util-to-markdown'
const doc = await fs.readFile('example.mdx')
const tree = fromMarkdown(doc, {
extensions: [mdxJsx({acorn, addResult: true})],
mdastExtensions: [mdxJsxFromMarkdown()]
})
console.log(tree)
const out = toMarkdown(tree, {extensions: [mdxJsxToMarkdown()]})
console.log(out)
`
…now running node example.js yields (positional info removed for brevity):
`js`
{
type: 'root',
children: [
{
type: 'mdxJsxFlowElement',
name: 'Box',
attributes: [],
children: [
{
type: 'list',
ordered: false,
start: null,
spread: false,
children: [
{
type: 'listItem',
spread: false,
checked: null,
children: [
{type: 'paragraph', children: [{type: 'text', value: 'a list'}]}
]
}
]
}
]
},
{
type: 'mdxJsxFlowElement',
name: 'MyComponent',
attributes: [
{
type: 'mdxJsxExpressionAttribute',
value: '...props',
data: {
estree: {
type: 'Program',
body: [
{
type: 'ExpressionStatement',
expression: {
type: 'ObjectExpression',
properties: [
{
type: 'SpreadElement',
argument: {type: 'Identifier', name: 'props'}
}
]
}
}
],
sourceType: 'module'
}
}
}
],
children: []
},
{
type: 'paragraph',
children: [
{
type: 'mdxJsxTextElement',
name: 'abbr',
attributes: [
{
type: 'mdxJsxAttribute',
name: 'title',
value: 'Hypertext Markup Language'
}
],
children: [{type: 'text', value: 'HTML'}]
},
{type: 'text', value: ' is a lovely language.'}
]
}
]
}
`markdown
* a list
HTML is a lovely language.
`
This package exports the identifiers
[mdxJsxFromMarkdown][api-mdx-jsx-from-markdown] andmdxJsxToMarkdown
[][api-mdx-jsx-to-markdown].
There is no default export.
Create an extension for
[mdast-util-from-markdown][mdast-util-from-markdown]
to enable MDX JSX.
###### Returns
Extension for mdast-util-from-markdown to enable MDX JSXFromMarkdownExtension
([][from-markdown-extension]).
When using the [micromark syntax extension][micromark-extension-mdx-jsx] with
addResult, nodes will have a data.estree field set to an ESTreeProgram
[][program] node.
Create an extension for
[mdast-util-to-markdown][mdast-util-to-markdown]
to enable MDX JSX.
This extension configures mdast-util-to-markdown withoptions.fences: true
[][mdast-util-to-markdown-fences] andoptions.resourceLink: true
[][mdast-util-to-markdown-resourcelink] too, do not
overwrite them!
###### Parameters
* options ([ToMarkdownOptions][api-to-markdown-options])
— configuration
###### Returns
Extension for mdast-util-to-markdown to enable MDX JSXFromMarkdownExtension
([][to-markdown-extension]).
MDX JSX attribute with a key (TypeScript type).
###### Type
`ts
import type {Literal} from 'mdast'
interface MdxJsxAttribute extends Literal {
type: 'mdxJsxAttribute'
name: string
value?: MdxJsxAttributeValueExpression | string | null | undefined
}
`
MDX JSX attribute value set to an expression (TypeScript type).
###### Type
`ts
import type {Program} from 'estree-jsx'
import type {Literal} from 'mdast'
interface MdxJsxAttributeValueExpression extends Literal {
type: 'mdxJsxAttributeValueExpression'
data?: {estree?: Program | null | undefined} & Literal['data']
}
`
MDX JSX attribute as an expression (TypeScript type).
###### Type
`ts
import type {Program} from 'estree-jsx'
import type {Literal} from 'mdast'
interface MdxJsxExpressionAttribute extends Literal {
type: 'mdxJsxExpressionAttribute'
data?: {estree?: Program | null | undefined} & Literal['data']
}
`
MDX JSX element node, occurring in flow (block) (TypeScript type).
###### Type
`ts
import type {BlockContent, DefinitionContent, Parent} from 'mdast'
export interface MdxJsxFlowElement extends Parent {
type: 'mdxJsxFlowElement'
name: string | null
attributes: Array
children: Array
}
`
Same as [MdxJsxFlowElement][api-mdx-jsx-flow-element], but registered with@types/hast (TypeScript type).
###### Type
`ts
import type {ElementContent, Parent} from 'hast'
export interface MdxJsxFlowElementHast extends Parent {
type: 'mdxJsxFlowElement'
name: string | null
attributes: Array
children: Array
}
`
MDX JSX element node, occurring in text (phrasing) (TypeScript type).
###### Type
`ts
import type {Parent, PhrasingContent} from 'mdast'
export interface MdxJsxTextElement extends Parent {
type: 'mdxJsxTextElement'
name: string | null
attributes: Array
children: Array
}
`
Same as [MdxJsxTextElement][api-mdx-jsx-text-element], but registered with@types/hast (TypeScript type).
###### Type
`ts
import type {ElementContent, Parent} from 'hast'
export interface MdxJsxTextElementHast extends Parent {
type: 'mdxJsxTextElement'
name: string | null
attributes: Array
children: Array
}
`
Configuration (TypeScript type).
##### Fields
* quote ('"' or "'", default: '"')quoteSmart
— preferred quote to use around attribute values
* (boolean, default: false)tightSelfClosing
— use the other quote if that results in less bytes
* (boolean, default: false)
— do not use an extra space when closing self-closing elements:
instead of printWidth
* (number, default: Infinity)80
— try and wrap syntax at this width.
When set to a finite number (say, ), the formatter will print
attributes on separate lines when a tag doesn’t fit on one line.
The normal behavior is to print attributes with spaces between them instead
of line endings
MDX JSX has no representation in HTML.
Though, when you are dealing with MDX, you will likely go through hast.
You can enable passing MDX JSX through to hast by configuring
[mdast-util-to-hast][mdast-util-to-hast] withpassThrough: ['mdxJsxFlowElement', 'mdxJsxTextElement'].
See [Syntax in micromark-extension-mdx-jsx][syntax].
The following interfaces are added to [mdast][] by this utility.
#### MdxJsxFlowElement
`idl
interface MdxJsxFlowElement <: Parent {
type: 'mdxJsxFlowElement'
}
MdxJsxFlowElement includes MdxJsxElement
`
MdxJsxFlowElement ([Parent][dfn-parent]) represents JSX in flow (block).
It can be used where [flow][dfn-content-flow] content is expected.
It includes the mixin [MdxJsxElement][dfn-mixin-mdx-jsx-element].
For example, the following markdown:
`markdown`
z
Yields:
`js`
{
type: 'mdxJsxFlowElement',
name: 'w',
attributes: [{type: 'mdxJsxAttribute', name: 'x', value: 'y'}],
children: [{type: 'paragraph', children: [{type: 'text', value: 'z'}]}]
}
#### MdxJsxTextElement
`idl
interface MdxJsxTextElement <: Parent {
type: 'mdxJsxTextElement'
}
MdxJsxTextElement includes MdxJsxElement
`
MdxJsxTextElement ([Parent][dfn-parent]) represents JSX in text (span,
inline).
It can be used where [phrasing][dfn-content-phrasing] content is
expected.
It includes the mixin [MdxJsxElement][dfn-mixin-mdx-jsx-element].
For example, the following markdown:
`markdown`
a d e.
Yields:
`js`
{
type: 'mdxJsxTextElement',
name: 'b',
attributes: [{type: 'mdxJsxAttribute', name: 'c', value: null}],
children: [{type: 'text', value: 'd'}]
}
#### MdxJsxElement
`idl
interface mixin MdxJsxElement {
name: string?
attributes: [MdxJsxExpressionAttribute | MdxJsxAttribute]
}
interface MdxJsxExpressionAttribute <: Literal {
type: 'mdxJsxExpressionAttribute'
}
interface MdxJsxAttribute <: Node {
type: 'mdxJsxAttribute'
name: string
value: MdxJsxAttributeValueExpression | string?
}
interface MdxJsxAttributeValueExpression <: Literal {
type: 'mdxJsxAttributeValueExpression'
}
`
MdxJsxElement represents a JSX element.
The name field can be present and represents an identifier.name
Without , the element represents a fragment, in which case no attributes
must be present.
The attributes field represents information associated with the node.attributes
The value of the field is a list of MdxJsxExpressionAttribute
and MdxJsxAttribute nodes.
MdxJsxExpressionAttribute represents an expression (typically in a
programming language) that when evaluated results in multiple attributes.
MdxJsxAttribute represents a single attribute.
The name field must be present.value
The field can be present, in which case it is either a string (a static
value) or an expression (typically in a programming language) that when
evaluated results in an attribute value.
###### FlowContent (MDX JSX)
`idl`
type MdxJsxFlowContent = MdxJsxFlowElement | FlowContent
###### PhrasingContent (MDX JSX)
`idl`
type MdxJsxPhrasingContent = MdxJsxTextElement | PhrasingContent
This package is fully typed with [TypeScript][].
It exports the additional types [MdxJsxAttribute][api-mdx-jsx-attribute],MdxJsxAttributeValueExpression
[][api-mdx-jsx-attribute-value-expression],MdxJsxExpressionAttribute
[][api-mdx-jsx-expression-attribute],MdxJsxFlowElement
[][api-mdx-jsx-flow-element],MdxJsxFlowElementHast
[][api-mdx-jsx-flow-element-hast],MdxJsxTextElement
[][api-mdx-jsx-text-element],MdxJsxTextElementHast
[][api-mdx-jsx-text-element-hast], andToMarkdownOptions
[][api-to-markdown-options].
It also registers the node types with @types/mdast and @types/hast.
If you’re working with the syntax tree, make sure to import this utility
somewhere in your types, as that registers the new node types in the tree.
`js
/**
* @import {} from 'mdast-util-mdx-jsx'
* @import {Root} from 'mdast'
*/
import {visit} from 'unist-util-visit'
/* @type {Root} /
const tree = getMdastNodeSomeHow()
visit(tree, function (node) {
// node can now be one of the JSX nodes.`
})
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, mdast-util-mdx-jsx@3,
compatible with Node.js 16.
This utility works with mdast-util-from-markdown version 2+ andmdast-util-to-markdown version 2+.
* [micromark/micromark-extension-mdx-jsx][micromark-extension-mdx-jsx]syntax-tree/mdast-util-mdx
— support MDX JSX in micromark
* [][mdast-util-mdx]remarkjs/remark-mdx
— support MDX in mdast
* [][remark-mdx]
— support MDX in remark
See [contributing.md][contributing] in [syntax-tree/.github][health] forsupport.md`][support] for ways to get help.
ways to get started.
See [
This project has a [code of conduct][coc].
By interacting with this repository, organization, or community you agree to
abide by its terms.
[MIT][license] © [Titus Wormer][author]
[build-badge]: https://github.com/syntax-tree/mdast-util-mdx-jsx/workflows/main/badge.svg
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[coverage]: https://codecov.io/github/syntax-tree/mdast-util-mdx-jsx
[downloads-badge]: https://img.shields.io/npm/dm/mdast-util-mdx-jsx.svg
[downloads]: https://www.npmjs.com/package/mdast-util-mdx-jsx
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[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/syntax-tree/unist/discussions
[npm]: https://docs.npmjs.com/cli/install
[esmsh]: https://esm.sh
[license]: license
[author]: https://wooorm.com
[health]: https://github.com/syntax-tree/.github
[contributing]: https://github.com/syntax-tree/.github/blob/main/contributing.md
[support]: https://github.com/syntax-tree/.github/blob/main/support.md
[coc]: https://github.com/syntax-tree/.github/blob/main/code-of-conduct.md
[esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c
[typescript]: https://www.typescriptlang.org
[mdast]: https://github.com/syntax-tree/mdast
[mdast-util-to-hast]: https://github.com/syntax-tree/mdast-util-to-hast
[mdast-util-from-markdown]: https://github.com/syntax-tree/mdast-util-from-markdown
[from-markdown-extension]: https://github.com/syntax-tree/mdast-util-from-markdown#extension
[mdast-util-to-markdown]: https://github.com/syntax-tree/mdast-util-to-markdown
[to-markdown-extension]: https://github.com/syntax-tree/mdast-util-to-markdown#options
[mdast-util-mdx]: https://github.com/syntax-tree/mdast-util-mdx
[program]: https://github.com/estree/estree/blob/master/es2015.md#programs
[dfn-parent]: https://github.com/syntax-tree/mdast#parent
[dfn-content-flow]: #flowcontent-mdx-jsx
[dfn-content-phrasing]: #phrasingcontent-mdx-jsx
[dfn-mixin-mdx-jsx-element]: #mdxjsxelement
[jsx]: https://facebook.github.io/jsx/
[what-is-mdx]: https://mdxjs.com/docs/what-is-mdx/
[micromark-extension-mdx-jsx]: https://github.com/micromark/micromark-extension-mdx-jsx
[syntax]: https://github.com/micromark/micromark-extension-mdx-jsx#syntax
[mdast-util-to-markdown-fences]: https://github.com/syntax-tree/mdast-util-to-markdown#optionsfences
[mdast-util-to-markdown-resourcelink]: https://github.com/syntax-tree/mdast-util-to-markdown#optionsresourcelink
[remark-mdx]: https://mdxjs.com/packages/remark-mdx/
[mdx]: https://mdxjs.com
[api-mdx-jsx-from-markdown]: #mdxjsxfrommarkdown
[api-mdx-jsx-to-markdown]: #mdxjsxtomarkdownoptions
[api-mdx-jsx-attribute]: #mdxjsxattribute
[api-mdx-jsx-attribute-value-expression]: #mdxjsxattributevalueexpression
[api-mdx-jsx-expression-attribute]: #mdxjsxexpressionattribute
[api-mdx-jsx-flow-element]: #mdxjsxflowelement
[api-mdx-jsx-flow-element-hast]: #mdxjsxflowelementhast
[api-mdx-jsx-text-element]: #mdxjsxtextelement
[api-mdx-jsx-text-element-hast]: #mdxjsxtextelementhast
[api-to-markdown-options]: #tomarkdownoptions