unified

Project: rehypejs/rehype-infer-reading-time-meta

Package: rehype-infer-reading-time-meta@1.1.0

  1. Dependents: 0
  2. rehype plugin to infer reading time as file metadata from the document
  1. unified 181
  2. plugin 138
  3. html 124
  4. rehype 91
  5. hast 75
  6. rehype-plugin 62
  7. file 34
  8. meta 8
  9. reading 3
  10. time 2
  11. reading-time 2

rehype-infer-reading-time-meta

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rehype plugin to infer the estimated reading time of a document.

Contents

What is this?

This package is a unified (rehype) plugin to infer the estimated reading time of a document. The estimation takes readability, calibrated relative to the target audience, into account.

unified is a project that transforms content with abstract syntax trees (ASTs). rehype adds support for HTML to unified. vfile is the virtual file interface used in unified. hast is the HTML AST that rehype uses. This is a rehype plugin that inspects hast and adds metadata to vfiles.

When should I use this?

This plugin is particularly useful in combination with rehype-meta. When both are used together and documents are shared, the estimated reading time is shown on Slack or certain other services.

Install

This package is ESM only. In Node.js (version 12.20+, 14.14+, 16.0+, or 18.0+), install with npm:

npm install rehype-infer-reading-time-meta

In Deno with esm.sh:

import rehypeInferReadingTimeMeta from 'https://esm.sh/rehype-infer-reading-time-meta@1'

In browsers with esm.sh:

<script type="module">
  import rehypeInferReadingTimeMeta from 'https://esm.sh/rehype-infer-reading-time-meta@1?bundle'
</script>

Use

Say our module example.js looks as follows:

import {unified} from 'unified'
import rehypeParse from 'rehype-parse'
import rehypeInferReadingTimeMeta from 'rehype-infer-reading-time-meta'
import rehypeDocument from 'rehype-document'
import rehypeMeta from 'rehype-meta'
import rehypeFormat from 'rehype-format'
import rehypeStringify from 'rehype-stringify'

const file = await unified()
  .use(rehypeParse, {fragment: true})
  .use(rehypeInferReadingTimeMeta)
  .use(rehypeDocument)
  .use(rehypeMeta, {twitter: true})
  .use(rehypeFormat)
  .use(rehypeStringify)
  .process(
    '<h1>Build</h1><p><strong>We provide the building blocks</strong>: from tiny, focussed, modular utilities to plugins that combine them to perform bigger tasks. And much, much more. You can build on unified, mixing and matching building blocks together, to make all kinds of interesting new things.</p>'
  )

console.log(String(file))

…now running node example.js yields:

<!doctype html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <meta name="twitter:card" content="summary">
    <meta name="twitter:label1" content="Reading time">
    <meta name="twitter:data1" content="1 minute">
  </head>
  <body>
    <h1>Build</h1>
    <p><strong>We provide the building blocks</strong>: from tiny, focussed, modular utilities to plugins that combine them to perform bigger tasks. And much, much more. You can build on unified, mixing and matching building blocks together, to make all kinds of interesting new things.</p>
  </body>
</html>

API

This package exports no identifiers. The default export is rehypeInferReadingTimeMeta.

unified().use(rehypeInferReadingTimeMeta, options?)

Infer the estimated reading time from a document as file metadata. The reading time is inferred not just on words per minute, but also takes readability into account. The result is stored on file.data.meta.readingTime.

options

Configuration (optional).

options.age

Target age group (number or [number, number], default: [16, 18]). This is the age your target audience was still in school. Set it to 18 if you expect all readers to have finished high school, 21 if you expect your readers to all be college graduates, etc. Can be two numbers in an array to get two estimates.

options.mainSelector

CSS selector to body of content (string, optional, example: 'main'). Useful to exclude other things, such as the head, ads, styles, scripts, and other random stuff, by focussing on one element.

Types

This package is fully typed with TypeScript. The additional type Options is exported.

It also registers the file.data.meta fields with vfile. If you’re working with the file, make sure to import this plugin somewhere in your types, as that registers the new fields on the file.

/**
 * @typedef {import('rehype-infer-title-meta')}
 */

import {VFile} from 'vfile'

const file = new VFile()

console.log(file.data.meta.readingTime) //=> TS now knows that this is a `(number | [number, number])?`.

Compatibility

Projects maintained by the unified collective are compatible with all maintained versions of Node.js. As of now, that is Node.js 12.20+, 14.14+, 16.0+, and 18.0+. Our projects sometimes work with older versions, but this is not guaranteed.

This plugin works with rehype-parse version 3+, rehype-stringify version 3+, rehype version 4+, and unified version 6+.

Security

Use of rehype-infer-reading-time-meta is safe.

Contribute

See contributing.md in rehypejs/.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, organization, or community you agree to abide by its terms.

License

MIT © Titus Wormer