hast-util-to-text

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[hast][] utility to get the plain-text value of a node.

Contents

* What is this?
* When should I use this?
* Install
* Use
* API
* [toText(tree[, options])](#totexttree-options)
* Options
* Whitespace
* Types
* Compatibility
* Security
* Related
* Contribute
* License

What is this?

This package is a utility that takes a [hast][] node and gets its plain-text
value.
It is like the DOMs Node#innerText, which is a bit nicer than
Node#textContent, because this turns
elements into line breaks and
uses '\t' (tabs) between table cells.

There are some small deviations from the spec, because the DOM has knowledge of
associated CSS, and can take into account that elements have display: none or
text-transform association with them, and this utility can’t do that.

When should I use this?

This is a small utility that is useful when you want a plain-text version of a
node that is close to how it’s “visible” to users.

This utility is similar to [hast-util-to-string][hast-util-to-string], which
is simpler, and more like the Node#textContent algorithm discussed above.

There is also a package [hast-util-from-text][hast-util-from-text], which sort
of does the inverse: it takes a string, sets that as text on the node, while
turning line endings into
s

Install

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

``sh
npm install hast-util-to-text
`

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

`js
import {toText} from 'https://esm.sh/hast-util-to-text@4'
`

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

`html

`

Use

`js
import {h} from 'hastscript'
import {toText} from 'hast-util-to-text'

const tree = h('div', [
h('h1', {hidden: true}, 'Alpha.'),
h('article', [
h('p', ['Bravo', h('br'), 'charlie.']),
h('p', 'Delta echo \t foxtrot.')
])
])

console.log(toText(tree))
`

Yields:

`txt
Bravo
charlie.

Delta echo foxtrot.
`

API

This package exports the identifier [toText][api-to-text].
There is no default export.

$3

Get the plain-text value of a node.

###### Parameters

* tree ([Node][node])
— tree to turn into text
* options ([Options][api-options], optional)
— configuration

###### Returns

Serialized tree (string).

###### Algorithm

* if tree is a [comment][], returns its value
* if tree is a [text][], applies normal whitespace collapsing to its
value, as defined by the [CSS Text][css] spec
* if tree is a [root][] or [element][], applies an algorithm similar to the
innerText getter as defined by [HTML][]

###### Notes

> 👉 Note: the algorithm acts as if tree is being rendered, and as if
> we’re a CSS-supporting user agent, with scripting enabled.

* if tree is an element that is not displayed (such as a head), we’ll
still use the innerText algorithm instead of switching to textContent
* if descendants of tree are elements that are not displayed, they are
ignored
* CSS is not considered, except for the default user agent style sheet
* a line feed is collapsed instead of ignored in cases where Fullwidth, Wide,
or Halfwidth East Asian Width characters are used, the same goes for a case
with Chinese, Japanese, or Yi writing systems
* replaced elements (such as audio) are treated like non-replaced elements

$3

Configuration (TypeScript type).

##### Fields

* whitespace ([Whitespace][api-whitespace], default: 'normal')
— default whitespace setting to use

$3

Valid and useful whitespace values (from [CSS][]) (TypeScript type).

##### Type

`ts
type Whitespace = 'normal' | 'nowrap' | 'pre' | 'pre-wrap'
`

Types

This package is fully typed with [TypeScript][].
It exports the additional types [Options][api-options] and
[Whitespace][api-whitespace].

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-to-text@^4,
compatible with Node.js 16.

Security

hast-util-to-text does not change the syntax tree so there are no
openings for [cross-site scripting (XSS)][xss] attacks.

Related

* hast-util-to-string

— get the plain-text value (textContent)
* hast-util-from-text
— set the plain-text value (innerText)
* hast-util-from-string

— set the plain-text value (textContent)

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/hast-util-to-text/workflows/main/badge.svg

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

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

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

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[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

[html]: https://html.spec.whatwg.org/multipage/dom.html#the-innertext-idl-attribute

[css]: https://drafts.csswg.org/css-text/#white-space-phase-1

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

[hast-util-from-text]: https://github.com/syntax-tree/hast-util-from-text

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

[node]: https://github.com/syntax-tree/hast#nodes

[root]: https://github.com/syntax-tree/hast#root

[comment]: https://github.com/syntax-tree/hast#comment

[text]: https://github.com/syntax-tree/hast#text

[element]: https://github.com/syntax-tree/hast#element

[xss]: https://en.wikipedia.org/wiki/Cross-site_scripting

[api-to-text]: #totexttree-options

[api-options]: #options

[api-whitespace]: #whitespace