mdast-util-from-markdown
mdast utility that turns markdown into a syntax tree.
Contents
- What is this?
- When should I use this?
- Install
- Use
- API
- List of extensions
- Syntax
- Syntax tree
- Types
- Compatibility
- Security
- Related
- Contribute
- License
What is this?
This package is a utility that takes markdown input and turns it into an mdast syntax tree.
This utility uses micromark
, which turns markdown into tokens,
and then turns those tokens into nodes.
This package is used inside remark-parse
, which focusses on
making it easier to transform content by abstracting these internals away.
When should I use this?
If you want to handle syntax trees manually, use this.
When you just want to turn markdown into HTML, use micromark
instead.
For an easier time processing content, use the remark ecosystem instead.
You can combine this package with other packages to add syntax extensions to
markdown.
Notable examples that deeply integrate with this package are
mdast-util-gfm
,
mdast-util-mdx
,
mdast-util-frontmatter
,
mdast-util-math
, and
mdast-util-directive
.
Install
This package is ESM only. In Node.js (version 16+), install with npm:
npm install mdast-util-from-markdown
In Deno with esm.sh
:
import {fromMarkdown} from 'https://esm.sh/mdast-util-from-markdown@2'
In browsers with esm.sh
:
<script type="module">
import {fromMarkdown} from 'https://esm.sh/mdast-util-from-markdown@2?bundle'
</script>
Use
Say we have the following markdown file example.md
:
## Hello, *World*!
…and our module example.js
looks as follows:
import fs from 'node:fs/promises'
import {fromMarkdown} from 'mdast-util-from-markdown'
const doc = await fs.readFile('example.md')
const tree = fromMarkdown(doc)
console.log(tree)
…now running node example.js
yields (positional info removed for brevity):
{
type: 'root',
children: [
{
type: 'heading',
depth: 2,
children: [
{type: 'text', value: 'Hello, '},
{type: 'emphasis', children: [{type: 'text', value: 'World'}]},
{type: 'text', value: '!'}
]
}
]
}
API
This package exports the identifier fromMarkdown
.
There is no default export.
The export map supports the development
condition.
Run node --conditions development example.js
to get instrumented dev code.
Without this condition, production code is loaded.
fromMarkdown(value[, encoding][, options])
Turn markdown into a syntax tree.
Overloads
(value: Value, encoding: Encoding, options?: Options) => Root
(value: Value, options?: Options) => Root
Parameters
-
value
(Value
) — markdown to parse -
encoding
(Encoding
, default:'utf8'
) — character encoding for whenvalue
isUint8Array
-
options
(Options
, optional) — configuration
Returns
mdast tree (Root
).
CompileContext
mdast compiler context (TypeScript type).
Fields
-
stack
(Array<Node>
) — stack of nodes -
tokenStack
(Array<[Token, OnEnterError | undefined]>
) — stack of tokens -
data
(CompileData
) — info passed around; key/value store -
buffer
(() => undefined
) — capture some of the output data -
resume
(() => string
) — stop capturing and access the output data -
enter
((node: Node, token: Token, onError?: OnEnterError) => undefined
) — enter a node -
exit
((token: Token, onError?: OnExitError) => undefined
) — exit a node -
sliceSerialize
((token: Token, expandTabs?: boolean) => string
) — get the string value of a token -
config
(Required<Extension>
) — configuration
CompileData
Interface of tracked data (TypeScript type).
Type
interface CompileData { /* see code */ }
When working on extensions that use more data, extend the corresponding interface to register their types:
declare module 'mdast-util-from-markdown' {
interface CompileData {
// Register a new field.
mathFlowInside?: boolean | undefined
}
}
Encoding
Encodings supported by the Uint8Array
class (TypeScript type).
See micromark
for more info.
Type
type Encoding = 'utf8' | /* … */
Extension
Change how markdown tokens from micromark are turned into mdast (TypeScript type).
Properties
-
canContainEols
(Array<string>
, optional) — token types where line endings are used -
enter
(Record<string, Handle>
, optional) — opening handles -
exit
(Record<string, Handle>
, optional) — closing handles -
transforms
(Array<Transform>
, optional) — tree transforms
Handle
Handle a token (TypeScript type).
Parameters
-
this
(CompileContext
) — context -
token
(Token
) — current token
Returns
Nothing (undefined
).
OnEnterError
Handle the case where the right
token is open, but it is closed (by the
left
token) or because we reached the end of the document (TypeScript type).
Parameters
-
this
(CompileContext
) — context -
left
(Token
orundefined
) — left token -
right
(Token
) — right token
Returns
Nothing (undefined
).
OnExitError
Handle the case where the right
token is open but it is closed by
exiting the left
token (TypeScript type).
Parameters
-
this
(CompileContext
) — context -
left
(Token
) — left token -
right
(Token
) — right token
Returns
Nothing (undefined
).
Options
Configuration (TypeScript type).
Properties
-
extensions
(Array<MicromarkExtension>
, optional) — micromark extensions to change how markdown is parsed -
mdastExtensions
(Array<Extension | Array<Extension>>
, optional) — extensions for this utility to change how tokens are turned into a tree
Token
Token from micromark (TypeScript type).
Type
type Token = { /* … */ }
Transform
Extra transform, to change the AST afterwards (TypeScript type).
Parameters
-
tree
(Root
) — tree to transform
Returns
New tree (Root
) or nothing (in which case the current tree is used).
Value
Contents of the file (TypeScript type).
See micromark
for more info.
Type
type Value = Uint8Array | string
List of extensions
-
syntax-tree/mdast-util-directive
— directives -
syntax-tree/mdast-util-frontmatter
— frontmatter (YAML, TOML, more) -
syntax-tree/mdast-util-gfm
— GFM -
syntax-tree/mdast-util-gfm-autolink-literal
— GFM autolink literals -
syntax-tree/mdast-util-gfm-footnote
— GFM footnotes -
syntax-tree/mdast-util-gfm-strikethrough
— GFM strikethrough -
syntax-tree/mdast-util-gfm-table
— GFM tables -
syntax-tree/mdast-util-gfm-task-list-item
— GFM task list items -
syntax-tree/mdast-util-math
— math -
syntax-tree/mdast-util-mdx
— MDX -
syntax-tree/mdast-util-mdx-expression
— MDX expressions -
syntax-tree/mdast-util-mdx-jsx
— MDX JSX -
syntax-tree/mdast-util-mdxjs-esm
— MDX ESM
Syntax
Markdown is parsed according to CommonMark. Extensions can add support for other syntax. If you’re interested in extending markdown, more information is available in micromark’s readme.
Syntax tree
The syntax tree is mdast.
Types
This package is fully typed with TypeScript.
It exports the additional types CompileContext
,
CompileData
,
Encoding
,
Extension
,
Handle
,
OnEnterError
,
OnExitError
,
Options
,
Token
,
Transform
, and
Value
.
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,
mdast-util-from-markdown@^2
, compatible with Node.js 16.
Security
As markdown is sometimes used for HTML, and improper use of HTML can open you up
to a cross-site scripting (XSS) attack, use of mdast-util-from-markdown
can also be unsafe.
When going to HTML, use this utility in combination with
hast-util-sanitize
to make the tree safe.
Related
-
syntax-tree/mdast-util-to-markdown
— serialize mdast as markdown -
micromark/micromark
— parse markdown -
remarkjs/remark
— process markdown
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.