docs/lib/get-mini-toc-items.js

40 строки
1.5 KiB
JavaScript

const cheerio = require('cheerio')
const { range } = require('lodash')
module.exports = function getMiniTocItems (html, maxHeadingLevel = 3) {
const $ = cheerio.load(html, { xmlMode: true })
// eg `h2, h3` or `h2, h3, h4` depending on maxHeadingLevel
const selector = range(2, maxHeadingLevel + 1).map(num => `h${num}`).join(', ')
const headings = $(selector)
// return an array of objects containing each heading's contents, level, and optional platform.
// layouts/article.html uses these as follows:
// - `contents` to render the mini TOC headings
// - `headingLevel` the `2` in `h2`; used for determining required indentation
// - `platform` to show or hide platform-specific headings via client JS
const items = headings
.get()
.map(item => {
// remove any <span> tags including their content
$('span').remove()
// remove any <strong> tags but leave content
$('strong').map((i, el) => $(el).replaceWith($(el).contents()))
const contents = $(item).html()
const headingLevel = Number($(item)[0].name.replace(/^h/, '')) // the `2` from `h2`
const platform = $(item).parent('.extended-markdown').attr('class')
return { contents, headingLevel, platform }
})
// determine indentation level for each item based on the largest
// heading level in the current article
const largestHeadingLevel = items.map(item => item.headingLevel).sort()[0]
items.forEach(item => {
item.indentationLevel = item.headingLevel - largestHeadingLevel
})
return items
}