mdast-util-find-and-replace

What is mdast-util-find-and-replace?

The mdast-util-find-and-replace npm package is a utility for finding and replacing text or patterns in Markdown Abstract Syntax Trees (MDAST). It is particularly useful for manipulating Markdown documents programmatically, allowing developers to automate content updates, apply transformations, and enhance Markdown processing workflows.

What are mdast-util-find-and-replace's main functionalities?

Text Replacement

This feature allows you to replace specific text in the MDAST. In the provided code, 'world' is replaced with 'universe' within the text node of a paragraph.

const u = require('unist-builder');
const findAndReplace = require('mdast-util-find-and-replace');

const tree = u('paragraph', [
  u('text', 'Hello world!')
]);

findAndReplace(tree, {'world': 'universe'});

console.log(tree);

Pattern Replacement with Callback

This feature allows replacing patterns using regular expressions. In the example, occurrences of 'example.com' are turned into clickable links.

const u = require('unist-builder');
const findAndReplace = require('mdast-util-find-and-replace');

const tree = u('paragraph', [
  u('text', 'Visit example.com for more info.')
]);

findAndReplace(tree, /example\.com/g, (match) => {
  return {
    type: 'link',
    url: 'http://example.com',
    children: [{type: 'text', value: match}]
  };
});

console.log(tree);

Other packages similar to mdast-util-find-and-replace

remark-retext

remark-retext is a plugin that bridges between remark (Markdown processor) and retext (natural language processor). While it focuses on natural language processing, it can be used in conjunction with plugins like retext-string-replace to achieve similar find-and-replace functionalities. However, it requires setting up a pipeline with retext, making it less direct than mdast-util-find-and-replace for simple replacements.

unist-util-visit

unist-util-visit is a utility for traversing Unist nodes, which can be used to manually implement find-and-replace functionalities by visiting nodes and modifying them. It offers more control and customization over how nodes are visited and modified compared to mdast-util-find-and-replace, which is more specialized and straightforward for text replacements.

README

mdast-util-find-and-replace

mdast utility to find and replace things.

Contents

• What is this?
• When should I use this?
• Install
• Use
• API
  • findAndReplace(tree, list[, options])
  • Find
  • FindAndReplaceList
  • FindAndReplaceTuple
  • Options
  • RegExpMatchObject
  • Replace
  • ReplaceFunction
• Types
• Compatibility
• Security
• Related
• Contribute
• License

What is this?

This package is a utility that lets you find patterns (string, RegExp) in text and replace them with nodes.

When should I use this?

This utility is typically useful when you have regexes and want to modify mdast. One example is when you have some form of “mentions” (such as /@([a-z][_a-z0-9])\b/gi) and want to create links to persons from them.

A similar package, hast-util-find-and-replace does the same but on hast.

Install

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

npm install mdast-util-find-and-replace

In Deno with esm.sh:

import {findAndReplace} from 'https://esm.sh/mdast-util-find-and-replace@3'

In browsers with esm.sh:

<script type="module">
  import {findAndReplace} from 'https://esm.sh/mdast-util-find-and-replace@3?bundle'
</script>

Use

import {findAndReplace} from 'mdast-util-find-and-replace'
import {u} from 'unist-builder'
import {inspect} from 'unist-util-inspect'

const tree = u('paragraph', [
  u('text', 'Some '),
  u('emphasis', [u('text', 'emphasis')]),
  u('text', ' and '),
  u('strong', [u('text', 'importance')]),
  u('text', '.')
])

findAndReplace(tree, [
  [/and/gi, 'or'],
  [/emphasis/gi, 'em'],
  [/importance/gi, 'strong'],
  [
    /Some/g,
    function ($0) {
      return u('link', {url: '//example.com#' + $0}, [u('text', $0)])
    }
  ]
])

console.log(inspect(tree))

Yields:

paragraph[8]
├─0 link[1]
│   │ url: "//example.com#Some"
│   └─0 text "Some"
├─1 text " "
├─2 emphasis[1]
│   └─0 text "em"
├─3 text " "
├─4 text "or"
├─5 text " "
├─6 strong[1]
│   └─0 text "strong"
└─7 text "."

API

This package exports the identifier findAndReplace. There is no default export.

findAndReplace(tree, list[, options])

Find patterns in a tree and replace them.

The algorithm searches the tree in preorder for complete values in Text nodes. Partial matches are not supported.

Parameters

• tree (Node) — tree to change
• list (FindAndReplaceList or FindAndReplaceTuple) — one or more find-and-replace pairs
• options (Options) — configuration

Returns

Nothing (undefined).

Find

Pattern to find (TypeScript type).

Strings are escaped and then turned into global expressions.

Type

type Find = RegExp | string

FindAndReplaceList

Several find and replaces, in array form (TypeScript type).

Type

type FindAndReplaceList = Array<FindAndReplaceTuple>

See FindAndReplaceTuple.

FindAndReplaceTuple

Find and replace in tuple form (TypeScript type).

Type

type FindAndReplaceTuple = [Find, Replace?]

See Find and Replace.

Options

Configuration (TypeScript type).

Fields

• ignore (Test, optional) — test for which elements to ignore

RegExpMatchObject

Info on the match (TypeScript type).

Fields

• index (number) — the index of the search at which the result was found
• input (string) — a copy of the search string in the text node
• stack (Array<Node>) — all ancestors of the text node, where the last node is the text itself

Replace

Thing to replace with (TypeScript type).

Type

type Replace = ReplaceFunction | string

See ReplaceFunction.

ReplaceFunction

Callback called when a search matches (TypeScript type).

Parameters

The parameters are the result of corresponding search expression:

• value (string) — whole match
• ...capture (Array<string>) — matches from regex capture groups
• match (RegExpMatchObject) — info on the match

Returns

Thing to replace with:

• when null, undefined, '', remove the match
• …or when false, do not replace at all
• …or when string, replace with a text node of that value
• …or when Node or Array<Node>, replace with those nodes

Types

This package is fully typed with TypeScript. It exports the additional types Find, FindAndReplaceList, FindAndReplaceTuple, Options, RegExpMatchObject, Replace, and ReplaceFunction.

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, mdast-util-find-and-replace@^3, compatible with Node.js 16.

Security

Use of mdast-util-find-and-replace does not involve hast or user content so there are no openings for cross-site scripting (XSS) attacks.

Related

• hast-util-find-and-replace — find and replace in hast
• hast-util-select — querySelector, querySelectorAll, and matches
• unist-util-select — select unist nodes with CSS-like selectors

Contribute

See contributing.md in syntax-tree/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organisation, or community you agree to abide by its terms.

License

MIT © Titus Wormer