# hast-util-to-html [![Build Status][travis-badge]][travis] [![Coverage Status][codecov-badge]][codecov]
Transform [HAST][] to HTML.
## Installation
[npm][]:
```bash
npm install hast-util-to-html
```
## Usage
```javascript
var h = require('hastscript')
var toHTML = require('hast-util-to-html')
var tree = h('.alpha', [
'bravo ',
h('b', 'charlie'),
' delta ',
h('a.echo', {download: true}, 'foxtrot')
])
console.log(toHTML(tree))
```
Yields:
```html
```
## API
### `toHTML(tree[, options])`
Stringify the given [HAST tree][hast].
###### `options.space`
Whether the root of the given tree is in the `'html'` or `'svg'` space (enum,
`'svg'` or `'html'`, default: `'html'`).
If an `svg` element is found in the HTML space, `toHTML` automatically switches
to the SVG space when entering the element, and switches back when leaving.
###### `options.entities`
Configuration for [`stringify-entities`][stringify-entities]
(`Object`, default: `{}`). Do not use `escapeOnly`, `attribute`, or
`subset` (`toHTML` already passes those). However, `useNamedReferences`,
`useShortestReferences`, and `omitOptionalSemicolons` are all fine.
###### `options.voids`
Tag-names of elements to stringify without closing tag (`Array.`,
default: [`html-void-elements`][html-void-elements]).
Not used in the SVG space.
###### `options.quote`
Preferred quote to use (`'"'` or `'\''`, default: `'"'`).
###### `options.quoteSmart`
Use the other quote if that results in less bytes (`boolean`, default:
`false`).
###### `options.preferUnquoted`
Leave attributes unquoted if that results in less bytes (`boolean`,
default: `false`).
Not used in the SVG space.
###### `options.omitOptionalTags`
Omit optional opening and closing tags (`boolean`, default: `false`).
For example, in `- one
- two
`, both ``
closing tags can be omitted. The first because it’s followed by
another `li`, the last because it’s followed by nothing.
Not used in the SVG space.
###### `options.collapseEmptyAttributes`
Collapse empty attributes: `class=""` is stringified as `class` instead
(`boolean`, default: `false`). **Note**: boolean attributes, such as
`hidden`, are always collapsed.
Not used in the SVG space.
###### `options.closeSelfClosing`
Close self-closing nodes with an extra slash (`/`): `
` instead of
`
` (`boolean`, default: `false`).
Not used in the SVG space.
###### `options.closeEmptyElements`
Close SVG elements without any content with slash (`/`) on the opening tag
instead of an end tag: `` instead of `` (`boolean`,
default: `false`).
Not used in the HTML space.
###### `options.tightSelfClosing`
Do not use an extra space when closing self-closing elements: `
`
instead of `
` (`boolean`, default: `false`). **Note**: Only used
if `closeSelfClosing: true` or `closeEmptyElements: true`.
###### `options.tightCommaSeparatedLists`
Join known comma-separated attribute values with just a comma (`,`),
instead of padding them on the right as well (`,·`, where `·` represents a
space) (`boolean`, default: `false`).
###### `options.tightAttributes`
Join attributes together, without white-space, if possible:
`class="a b" title="c d"` is stringified as `class="a b"title="c d"`
instead to save bytes (`boolean`, default: `false`). **Note**: creates
invalid (but working) markup.
Not used in the SVG space.
###### `options.tightDoctype`
Drop unneeded spaces in doctypes: `` instead of ``
to save bytes (`boolean`, default: `false`). **Note**: creates
invalid (but working) markup.
###### `options.allowParseErrors`
Do not encode characters which trigger parse errors (even though they
work), to save bytes (`boolean`, default: `false`). **Note**: creates
invalid (but working) markup.
Not used in the SVG space.
###### `options.allowDangerousCharacters`
Do not encode some characters which cause XSS vulnerabilities in older
browsers (`boolean`, default: `false`). **Note**: Only set this if you
completely trust the content.
###### `options.allowDangerousHTML`
Allow `raw` nodes and insert them as raw HTML. When falsey, encodes
`raw` nodes (`boolean`, default: `false`). **Note**: Only set this if
you completely trust the content.
## Related
* [`hast-util-sanitize`][hast-util-sanitize]
— Sanitize HAST nodes
* [`rehype-stringify`](https://github.com/wooorm/rehype/tree/master/packages/rehype-stringify)
— Wrapper around this project for [**rehype**](https://github.com/wooorm/rehype)
## Contribute
See [`contributing.md` in `syntax-tree/hast`][contributing] for ways to get
started.
This organisation has a [Code of Conduct][coc]. By interacting with this
repository, organisation, or community you agree to abide by its terms.
## License
[MIT][license] © [Titus Wormer][author]
[travis-badge]: https://img.shields.io/travis/syntax-tree/hast-util-to-html.svg
[travis]: https://travis-ci.org/syntax-tree/hast-util-to-html
[codecov-badge]: https://img.shields.io/codecov/c/github/syntax-tree/hast-util-to-html.svg
[codecov]: https://codecov.io/github/syntax-tree/hast-util-to-html
[npm]: https://docs.npmjs.com/cli/install
[license]: LICENSE
[author]: http://wooorm.com
[hast]: https://github.com/syntax-tree/hast
[html-void-elements]: https://github.com/wooorm/html-void-elements
[stringify-entities]: https://github.com/wooorm/stringify-entities
[hast-util-sanitize]: https://github.com/syntax-tree/hast-util-sanitize
[contributing]: https://github.com/syntax-tree/hast/blob/master/contributing.md
[coc]: https://github.com/syntax-tree/hast/blob/master/code-of-conduct.md