mdast-util-gfm-table

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[mdast][] extensions to parse and serialize [GFM][] tables.

Contents

* What is this?
* When to use this
* Install
* Use
* API
* gfmTableFromMarkdown
* gfmTableToMarkdown(options?)
* Options
* Examples
* Example: stringLength
* HTML
* Syntax
* Syntax tree
* Nodes
* Enumeration
* Content model
* Types
* Compatibility
* Related
* Contribute
* License

What is this?

This package contains two extensions that add support for GFM table syntax in
markdown to [mdast][].
These extensions plug into
[mdast-util-from-markdown][mdast-util-from-markdown] (to support parsing
tables in markdown into a syntax tree) and
[mdast-util-to-markdown][mdast-util-to-markdown] (to support serializing
tables in syntax trees to markdown).

When to use this

You can use these extensions when you are working with
mdast-util-from-markdown and mdast-util-to-markdown already.

When working with mdast-util-from-markdown, you must combine this package
with [micromark-extension-gfm-table][extension].

When you don’t need a syntax tree, you can use [micromark][micromark]
directly with micromark-extension-gfm-table.

When you are working with syntax trees and want all of GFM, use
[mdast-util-gfm][mdast-util-gfm] instead.

All these packages are used [remark-gfm][remark-gfm], which
focusses on making it easier to transform content by abstracting these
internals away.

This utility does not handle how markdown is turned to HTML.
That’s done by [mdast-util-to-hast][mdast-util-to-hast].

Install

This package is [ESM only][esm].
In Node.js (version 16+), install with [npm][]:

``sh
npm install mdast-util-gfm-table
`

In Deno with [esm.sh][esmsh]:

`js
import {gfmTableFromMarkdown, gfmTableToMarkdown} from 'https://esm.sh/mdast-util-gfm-table@2'
`

In browsers with [esm.sh][esmsh]:

`html

`

Use

Say our document example.md contains:

`markdown
| a | b | c | d |
| - | :- | -: | :-: |
| e | f |
| g | h | i | j | k |
`

…and our module example.js looks as follows:

`js
import fs from 'node:fs/promises'
import {gfmTable} from 'micromark-extension-gfm-table'
import {fromMarkdown} from 'mdast-util-from-markdown'
import {gfmTableFromMarkdown, gfmTableToMarkdown} from 'mdast-util-gfm-table'
import {toMarkdown} from 'mdast-util-to-markdown'

const doc = await fs.readFile('example.md')

const tree = fromMarkdown(doc, {
extensions: [gfmTable()],
mdastExtensions: [gfmTableFromMarkdown()]
})

console.log(tree)

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

console.log(out)
`

…now running node example.js yields (positional info removed for brevity):

`js
{
type: 'root',
children: [
{
type: 'table',
align: [null, 'left', 'right', 'center'],
children: [
{
type: 'tableRow',
children: [
{type: 'tableCell', children: [{type: 'text', value: 'a'}]},
{type: 'tableCell', children: [{type: 'text', value: 'b'}]},
{type: 'tableCell', children: [{type: 'text', value: 'c'}]},
{type: 'tableCell', children: [{type: 'text', value: 'd'}]}
]
},
{
type: 'tableRow',
children: [
{type: 'tableCell', children: [{type: 'text', value: 'e'}]},
{type: 'tableCell', children: [{type: 'text', value: 'f'}]}
]
},
{
type: 'tableRow',
children: [
{type: 'tableCell', children: [{type: 'text', value: 'g'}]},
{type: 'tableCell', children: [{type: 'text', value: 'h'}]},
{type: 'tableCell', children: [{type: 'text', value: 'i'}]},
{type: 'tableCell', children: [{type: 'text', value: 'j'}]},
{type: 'tableCell', children: [{type: 'text', value: 'k'}]}
]
}
]
}
]
}
`

`markdown
| a | b | c | d | |
| - | :- | -: | :-: | - |
| e | f | | | |
| g | h | i | j | k |
`

API

This package exports the identifiers
[gfmTableFromMarkdown][api-gfm-table-from-markdown] and
[gfmTableToMarkdown][api-gfm-table-to-markdown].
There is no default export.

$3

Create an extension for [mdast-util-from-markdown][mdast-util-from-markdown]
to enable GFM tables in markdown.

###### Returns

Extension for mdast-util-from-markdown to enable GFM tables
([FromMarkdownExtension][from-markdown-extension]).

$3

Create an extension for [mdast-util-to-markdown][mdast-util-to-markdown] to
enable GFM tables in markdown.

###### Parameters

* options ([Options][api-options], optional)
— configuration

###### Returns

Extension for mdast-util-to-markdown to enable GFM tables
([ToMarkdownExtension][to-markdown-extension]).

$3

Configuration (TypeScript type).

###### Fields

* tableCellPadding (boolean, default: true)
— whether to add a space of padding between delimiters and cells
* tablePipeAlign (boolean, default: true)
— whether to align the delimiters
* stringLength (((value: string) => number), default: s => s.length)
— function to detect the length of table cell content, used when aligning
the delimiters between cells

Examples

$3

It’s possible to align tables based on the visual width of cells.
First, let’s show the problem:

`js
import {gfmTable} from 'micromark-extension-gfm-table'
import {fromMarkdown} from 'mdast-util-from-markdown'
import {gfmTableFromMarkdown, gfmTableToMarkdown} from 'mdast-util-gfm-table'
import {toMarkdown} from 'mdast-util-to-markdown'

const doc = | Alpha | Bravo |
| - | - |
| 中文 | Charlie |
| 👩‍❤️‍👩 | Delta |

const tree = fromMarkdown(doc, {
extensions: [gfmTable],
mdastExtensions: [gfmTableFromMarkdown]
})

console.log(toMarkdown(tree, {extensions: [gfmTableToMarkdown()]}))
`

The above code shows how these utilities can be used to format markdown.
The output is as follows:

`markdown
| Alpha | Bravo |
| -------- | ------- |
| 中文 | Charlie |
| 👩‍❤️‍👩 | Delta |
`

To improve the alignment of these full-width characters and emoji, pass a
stringLength function that calculates the visual width of cells.
One such algorithm is [string-width][string-width].
It can be used like so:

`diff
@@ -2,6 +2,7 @@ import {gfmTable} from 'micromark-extension-gfm-table'
import {fromMarkdown} from 'mdast-util-from-markdown'
import {gfmTableFromMarkdown, gfmTableToMarkdown} from 'mdast-util-gfm-table'
import {toMarkdown} from 'mdast-util-to-markdown'
+import stringWidth from 'string-width'

const doc = | Alpha | Bravo |
| - | - |
@@ -13,4 +14,8 @@ const tree = fromMarkdown(doc, {
mdastExtensions: [gfmTableFromMarkdown()]
})

-console.log(toMarkdown(tree, {extensions: [gfmTableToMarkdown()]}))
+console.log(
+ toMarkdown(tree, {
+ extensions: [gfmTableToMarkdown({stringLength: stringWidth})]
+ })
+)
``

The output of our code with these changes is as follows:

`markdown
| Alpha | Bravo |
| ----- | ------- |
| 中文 | Charlie |
| 👩‍❤️‍👩 | Delta |
`

HTML

This utility does not handle how markdown is turned to HTML.
That’s done by [mdast-util-to-hast][mdast-util-to-hast].

Syntax

See [Syntax in micromark-extension-gfm-table][syntax].

Syntax tree

The following interfaces are added to [mdast][] by this utility.

$3

#### Table

`idl
interface Table <: Parent {
type: 'table'
align: [alignType]?
children: [TableContent]
}
`

Table ([Parent][dfn-parent]) represents two-dimensional data.

Table can be used where [flow][dfn-flow-content] content is expected.
Its content model is [table][dfn-table-content] content.

The [head][term-head] of the node represents the labels of the columns.

An align field can be present.
If present, it must be a list of [alignTypes][dfn-enum-align-type].
It represents how cells in columns are aligned.

For example, the following markdown:

`markdown
| foo | bar |
| :-- | :-: |
| baz | qux |
`

Yields:

`js
{
type: 'table',
align: ['left', 'center'],
children: [
{
type: 'tableRow',
children: [
{
type: 'tableCell',
children: [{type: 'text', value: 'foo'}]
},
{
type: 'tableCell',
children: [{type: 'text', value: 'bar'}]
}
]
},
{
type: 'tableRow',
children: [
{
type: 'tableCell',
children: [{type: 'text', value: 'baz'}]
},
{
type: 'tableCell',
children: [{type: 'text', value: 'qux'}]
}
]
}
]
}
`

#### TableRow

`idl
interface TableRow <: Parent {
type: "tableRow"
children: [RowContent]
}
`

TableRow ([Parent][dfn-parent]) represents a row of cells in a table.

TableRow can be used where [table][dfn-table-content] content is
expected.
Its content model is [row][dfn-row-content] content.

If the node is a [head][term-head], it represents the labels of the columns
for its parent [Table][dfn-table].

For an example, see [Table][dfn-table].

#### TableCell

`idl
interface TableCell <: Parent {
type: "tableCell"
children: [PhrasingContent]
}
`

TableCell ([Parent][dfn-parent]) represents a header cell in a
[Table][dfn-table], if its parent is a [head][term-head], or a data
cell otherwise.

TableCell can be used where [row][dfn-row-content] content is expected.
Its content model is [phrasing][dfn-phrasing-content] content excluding
[Break][dfn-break] nodes.

For an example, see [Table][dfn-table].

$3

#### alignType

`idl
enum alignType {
'center' | 'left' | 'right' | null
}
`

alignType represents how phrasing content is aligned
([\[CSSTEXT\]][css-text]).

* 'left': See the [left][css-left] value of the text-align CSS
property
* 'right': See the [right][css-right] value of the text-align
CSS property
* 'center': See the [center][css-center] value of the text-align
CSS property
* null: phrasing content is aligned as defined by the host environment

$3

#### FlowContent (GFM table)

`idl
type FlowContentGfm = Table | FlowContent
`

#### TableContent

`idl
type TableContent = TableRow
`

Table content represent the rows in a table.

#### RowContent

`idl
type RowContent = TableCell
`

Row content represent the cells in a row.

Types

This package is fully typed with [TypeScript][].
It exports the additional type [Options][api-options].

The Table, TableRow, and TableCell types of the mdast nodes are exposed
from @types/mdast.

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-gfm-table@^2,
compatible with Node.js 16.

This utility works with mdast-util-from-markdown version 2+ and
mdast-util-to-markdown version 2+.

Related

* [remarkjs/remark-gfm][remark-gfm]
— remark plugin to support GFM
* [syntax-tree/mdast-util-gfm][mdast-util-gfm]
— same but all of GFM (autolink literals, footnotes, strikethrough, tables,
tasklists)
* [micromark/micromark-extension-gfm-table][extension]
— micromark extension to parse GFM tables

Contribute

See [contributing.md][contributing] in [syntax-tree/.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]

[build-badge]: https://github.com/syntax-tree/mdast-util-gfm-table/workflows/main/badge.svg

[build]: https://github.com/syntax-tree/mdast-util-gfm-table/actions

[coverage-badge]: https://img.shields.io/codecov/c/github/syntax-tree/mdast-util-gfm-table.svg

[coverage]: https://codecov.io/github/syntax-tree/mdast-util-gfm-table

[downloads-badge]: https://img.shields.io/npm/dm/mdast-util-gfm-table.svg

[downloads]: https://www.npmjs.com/package/mdast-util-gfm-table

[size-badge]: https://img.shields.io/badge/dynamic/json?label=minzipped%20size&query=$.size.compressedSize&url=https://deno.bundlejs.com/?q=mdast-util-gfm-table

[size]: https://bundlejs.com/?q=mdast-util-gfm-table

[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

[esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c

[esmsh]: https://esm.sh

[typescript]: https://www.typescriptlang.org

[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

[remark-gfm]: https://github.com/remarkjs/remark-gfm

[mdast]: https://github.com/syntax-tree/mdast

[mdast-util-gfm]: https://github.com/syntax-tree/mdast-util-gfm

[mdast-util-from-markdown]: https://github.com/syntax-tree/mdast-util-from-markdown

[mdast-util-to-markdown]: https://github.com/syntax-tree/mdast-util-to-markdown

[mdast-util-to-hast]: https://github.com/syntax-tree/mdast-util-to-hast

[micromark]: https://github.com/micromark/micromark

[extension]: https://github.com/micromark/micromark-extension-gfm-table

[syntax]: https://github.com/micromark/micromark-extension-gfm-table#syntax

[gfm]: https://github.github.com/gfm/

[string-width]: https://github.com/sindresorhus/string-width

[css-text]: https://drafts.csswg.org/css-text/

[css-left]: https://drafts.csswg.org/css-text/#valdef-text-align-left

[css-right]: https://drafts.csswg.org/css-text/#valdef-text-align-right

[css-center]: https://drafts.csswg.org/css-text/#valdef-text-align-center

[term-head]: https://github.com/syntax-tree/unist#head

[dfn-parent]: https://github.com/syntax-tree/mdast#parent

[dfn-phrasing-content]: https://github.com/syntax-tree/mdast#phrasingcontent

[dfn-break]: https://github.com/syntax-tree/mdast#break

[from-markdown-extension]: https://github.com/syntax-tree/mdast-util-from-markdown#extension

[to-markdown-extension]: https://github.com/syntax-tree/mdast-util-to-markdown#options

[api-gfm-table-from-markdown]: #gfmtablefrommarkdown

[api-gfm-table-to-markdown]: #gfmtabletomarkdownoptions

[api-options]: #options

[dfn-flow-content]: #flowcontent-gfm-table

[dfn-table-content]: #tablecontent

[dfn-enum-align-type]: #aligntype

[dfn-row-content]: #rowcontent

[dfn-table]: #table