xastscript
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!Chatchat-badgechatxast utility to create trees with ease.
Contents
* [`x(name?[, attributes][, …children])`](#xname-attributes-children)
* [`Attributes`](#attributes-1)
* [`Child`](#child)
* [`Result`](#result)
What is this?
This package is a hyperscript interface (likecreateElement
from React and
such) to help with creating xast trees.When should I use this?
You can use this utility in your project when you generate xast syntax trees with code. It helps because it replaces most of the repetition otherwise needed in a syntax tree with function calls.You can instead use
unist-builder
u when creating any unist nodes and
hastscript
h when creating hast (HTML) nodes.Install
This package is ESM onlyesm. In Node.js (version 14.14+ and 16.0+), install with npm:npm install xastscript
In Deno with
esm.sh
esmsh:import {x} from 'https://esm.sh/xastscript@3'
In browsers with
esm.sh
esmsh:<script type="module">
import {x} from 'https://esm.sh/xastscript@3?bundle'
</script>
Use
import {u} from 'unist-builder'
import {x} from 'xastscript'
// Children as an array:
console.log(
x('album', {id: 123}, [
x('name', 'Born in the U.S.A.'),
x('artist', 'Bruce Springsteen'),
x('releasedate', '1984-04-06')
])
)
// Children as arguments:
console.log(
x(
'album',
{id: 123},
x('name', 'Exile in Guyville'),
x('artist', 'Liz Phair'),
x('releasedate', '1993-06-22')
)
)
// For other xast nodes, such as comments, instructions, doctypes, or cdata
// can be created with unist-builder:
console.log(
x(null, [
u('instruction', {name: 'xml'}, 'version="1.0" encoding="UTF-8"'),
x('album', [
u('comment', 'Great album!'),
x('name', 'Born in the U.S.A.'),
x('description', [u('cdata', '3 < 5 & 8 > 13')])
])
])
)
Yields:
{
type: 'element',
name: 'album',
attributes: {id: '123'},
children: [
{
type: 'element',
name: 'name',
attributes: {},
children: [{type: 'text', value: 'Born in the U.S.A.'}]
},
{
type: 'element',
name: 'artist',
attributes: {},
children: [{type: 'text', value: 'Bruce Springsteen'}]
},
{
type: 'element',
name: 'releasedate',
attributes: {},
children: [{type: 'text', value: '1984-04-06'}]
}
]
}
{
type: 'element',
name: 'album',
attributes: {id: '123'},
children: [
{
type: 'element',
name: 'name',
attributes: {},
children: [{type: 'text', value: 'Exile in Guyville'}]
},
{
type: 'element',
name: 'artist',
attributes: {},
children: [{type: 'text', value: 'Liz Phair'}]
},
{
type: 'element',
name: 'releasedate',
attributes: {},
children: [{type: 'text', value: '1993-06-22'}]
}
]
}
{
type: 'root',
children: [
{type: 'instruction', name: 'xml', value: 'version="1.0" encoding="UTF-8"'},
{
type: 'element',
name: 'album',
attributes: {},
children: [
{type: 'comment', value: 'Great album!'},
{
type: 'element',
name: 'name',
attributes: {},
children: [{type: 'text', value: 'Born in the U.S.A.'}]
},
{
type: 'element',
name: 'description',
attributes: {},
children: [{type: 'cdata', value: '3 < 5 & 8 > 13'}]
}
]
}
]
}
API
This package exports the identifierx
x.
There is no default export.The export map supports the automatic JSX runtime. You can pass
xastscript
to your build tool (TypeScript, Babel, SWC) with an
importSource
option or similar.x(name?[, attributes][, …children])
Create xast trees.Signatures
x(): root
x(null[, …children]): root
x(name[, attributes][, …children]): element
Parameters
name
Qualified name (string
, optional).Case sensitive and can contain a namespace prefix (such as
rdf:RDF
).
When string, an Element
element is built.
When nullish, a Root
root is built instead.attributes
Attributes of the element (Attributes
attributes, optional).children
Children of the node (Child
child or Array<Child>
, optional).Returns
Created tree (Result
result).Element
element when a name
is passed, otherwise Root
root.Attributes
Map of attributes (TypeScript type).Nullish (
null
or undefined
) or NaN
values are ignored, other values are
turned to strings.Type
type Attributes = Record<string, string | number | boolean | null | undefined>
Child
(Lists of) children (TypeScript type).When strings or numbers are encountered, they are turned into
Text
text
nodes.
Root
root nodes are treated as “fragments”, meaning that their children
are used instead.Type
type Child =
| string
| number
| null
| undefined
| Node
| Array<string | number | null | undefined | Node>
Result
Result from a x
call (TypeScript type).Type
type Result = Root | Element
Syntax tree
The syntax tree is xast.JSX
This package can be used with JSX. You should use the automatic JSX runtime set toxastscript
.🪦 Legacy: you can also use the classic JSX runtime, but this is not recommended. To do so, importx
yourself and define it as the pragma (plus set the fragment tonull
).
The Use example above (omitting the second) can then be written like so:
/** @jsxImportSource x */
import {u} from 'unist-builder'
console.log(
<album id={123}>
<name>Born in the U.S.A.</name>
<artist>Bruce Springsteen</artist>
<releasedate>1984-04-06</releasedate>
</album>
)
console.log(
<>
{u('instruction', {name: 'xml'}, 'version="1.0" encoding="UTF-8"')}
<album>
{u('comment', 'Great album!')}
<name>Born in the U.S.A.</name>
<description>{u('cdata', '3 < 5 & 8 > 13')}</description>
</album>
</>
)
Types
This package is fully typed with TypeScript. It exports the additional typesAttributes
attributes, Child
child,
and Result
result.Compatibility
Projects maintained by the unified collective are compatible with all maintained versions of Node.js. As of now, that is Node.js 14.14+ and 16.0+. Our projects sometimes work with older versions, but this is not guaranteed.Security
XML can be a dangerous language: don’t trust user-provided data.Related
— create any unist tree
— create a hast tree
— serialize xast as XML
— parse xast from XML
— transform hast to xast
Contribute
Seecontributing.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 conductcoc. By interacting with this repository, organization, or community you agree to abide by its terms.