unist-util-modify-children

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[unist][] utility to change children of a parent.

Contents

* What is this?
* When should I use this?
* Install
* Use
* API
* modifyChildren(modifier)
* Modifier
* Modify
* Types
* Compatibility
* Related
* Contribute
* License

What is this?

This is a tiny utility that you can use to create a reusable function that
modifies children.

When should I use this?

Probably never!
Use [unist-util-visit][unist-util-visit].

Install

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

``sh
npm install unist-util-modify-children
`

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

`js
import {modifyChildren} from 'https://esm.sh/unist-util-modify-children@4'
`

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

`html

`

Use

`js
import u from 'unist-builder'
import {modifyChildren} from 'unist-util-modify-children'

const tree = u('root', [
u('leaf', '1'),
u('parent', [u('leaf', '2')]),
u('leaf', '3')
])
const modify = modifyChildren(function (node, index, parent) {
if (node.type === 'parent') {
parent.children.splice(index, 1, {type: 'subtree', children: parent.children})
return index + 1
}
})

modify(tree)

console.dir(tree, {depth: undefined})
`

Yields:

`js
{
type: 'root',
children: [
{type: 'leaf', value: '1'},
{type: 'subtree', children: [{type: 'leaf', value: '2'}]},
{type: 'leaf', value: '3'}
]
}
`

API

This package exports the identifier [modifyChildren][api-modifychildren].
There is no default export.

$3

Wrap modifier to be called for each child in the nodes later given to
modify.

###### Parameters

* modifier ([Modifier][api-modifier])
— callback called for each child in parent later given to modify

###### Returns

Modify children of parent ([Modify][api-modify]).

$3

Callback called for each child in parent later given to modify
(TypeScript type).

###### Parameters

* child ([Node][node])
— child of parent
* index (number)
— position of child in parent
* parent ([Node][node])
— parent node

###### Returns

Position to move to next (optional) (number or undefined).

$3

Modify children of parent (TypeScript type).

###### Parameters

* parent ([Node][node])
— parent node

###### Returns

Nothing (undefined).

Types

This package is fully typed with [TypeScript][].
It exports the additional types [Modifier][api-modifier] and
[Modify][api-modify].

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,
unist-util-modify-children@^4, compatible with Node.js 16.

Related

* unist-util-visit
— walk the tree
* unist-util-visit-parents
— walk the tree with a stack of parents
* unist-util-filter
— create a new tree with all nodes that pass a test
* unist-util-map
— create a new tree with all nodes mapped by a given function
* unist-util-flatmap
— create a new tree by mapping (to an array) with the given function
* unist-util-find-after
— find a node after another node
* unist-util-find-before
— find a node before another node
* unist-util-find-all-after
— find all nodes after another node
* unist-util-find-all-before
— find all nodes before another node
* unist-util-find-all-between
— find all nodes between two nodes
* unist-util-remove
— remove nodes from a tree that pass a test
* unist-util-select
— select nodes with CSS-like selectors

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/unist-util-modify-children/workflows/main/badge.svg

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[downloads]: https://www.npmjs.com/package/unist-util-modify-children

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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

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

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

[unist-util-visit]: https://github.com/syntax-tree/unist-util-visit

[api-modifychildren]: #modifychildrenmodifier

[api-modifier]: #modifier

[api-modify]: #modify