hast-util-format

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[hast][] utility to format whitespace in HTML.

Contents

* What is this?
* When should I use this?
* Install
* Use
* API
* Options
* format(tree, options)
* Compatibility
* Related
* Security
* Contribute
* License

What is this?

This package is a utility that formats whitespace in HTML.
In short, it works as follows:

* collapse all existing whitespace to either a line ending or a single space
([hast-util-minify-whitespace][hast-util-minify-whitespace])
* remove those spaces and line endings if they do not contribute to the
document
* inject needed line endings
* indent previously collapsed line endings properly

When should I use this?

This package is useful when you want to improve the readability of an HTML
fragment as it adds insignificant but pretty whitespace between elements.
The plugin [rehype-format][rehype-format] uses this package to format HTML
at the plugin level.
The package [hast-util-minify-whitespace][hast-util-minify-whitespace] does
the inverse.

Install

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

``sh
npm install hast-util-format
`

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

`js
import {format} from 'https://esm.sh/hast-util-format@1'
`

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

`html

`

Use

Say we have the following example.html:

`html







hi there




`

Say we have the following example.js:

`js
import fs from 'node:fs/promises'
import {format} from 'hast-util-format'
import {fromHtml} from 'hast-util-from-html'
import {toHtml} from 'hast-util-to-html'

const document = await fs.readFile('example.html', 'utf8')

const tree = fromHtml(document)

format(tree)

const result = toHtml(tree)

console.log(result)
`

…now running node example.js yields:

`html









hi there




`

> 👉 Note:
> some of the changes have been made by hast-util-to-html.

API

$3

Configuration.

###### Fields

* blanks? (Array | null | undefined)
— list of tag names to join with a blank line (default: []);
these tags,
when next to each other,
are joined by a blank line (\n\n);
for example,
when ['head', 'body'] is given,
a blank line is added between these two
* indent? (string | number | null | undefined)
— indentation per level (default: 2);
when number,
uses that amount of spaces; when string,
uses that per indentation level
* indentInitial? (boolean | null | undefined)
— whether to indent the first level (default: true);
this is usually the ,
thus not indenting head and body

$3

Format whitespace in HTML.

###### Parameters

* tree (Root)
— tree
* options? (Options | null | undefined)
— configuration (optional)

###### Returns

Nothing (undefined).

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, hast-util-format@1,
compatible with Node.js 16.

Related

* [hast-util-minify-whitespace][hast-util-minify-whitespace]
— minify whitespace between elements

Security

This package is safe.

Contribute

See [contributing.md in syntax-tree/.github][contributing] 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/hast-util-format/workflows/main/badge.svg

[build]: https://github.com/syntax-tree/hast-util-format/actions

[coverage-badge]: https://img.shields.io/codecov/c/github/syntax-tree/hast-util-format.svg

[coverage]: https://codecov.io/github/syntax-tree/hast-util-format

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[downloads]: https://www.npmjs.com/package/hast-util-format

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[sponsors-badge]: https://opencollective.com/unified/sponsors/badge.svg

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[collective]: https://opencollective.com/unified

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[chat]: https://github.com/syntax-tree/unist/discussions

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

[npm]: https://docs.npmjs.com/cli/install

[esmsh]: https://esm.sh

[license]: license

[author]: https://wooorm.com

[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

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

[hast-util-minify-whitespace]: https://github.com/rehypejs/rehype-minify/tree/main/packages/hast-util-minify-whitespace

[rehype-format]: https://github.com/rehypejs/rehype-format