Function generateTableOfContents

docs/lib/transform-html.js:108–143

(document)

}

function generateTableOfContents (document) {
  const headers = walkHeaders(document.getElementById('_content'))

  // The nesting depth of headers are not necessarily the header level.
  // (eg, h1 > h3 > h5 is a depth of three even though there's an h5.)
  const hierarchy = []
  for (const header of headers) {
    const level = headerLevel(header)

    while (hierarchy.length && hierarchy[hierarchy.length - 1].headerLevel > level) {
      hierarchy.pop()
    }

    if (!hierarchy.length || hierarchy[hierarchy.length - 1].headerLevel < level) {
      const newList = document.createElement('ul')
      newList.headerLevel = level

      if (hierarchy.length) {
        hierarchy[hierarchy.length - 1].appendChild(newList)
      }

      hierarchy.push(newList)
    }

    const element = document.createElement('li')

    const link = document.createElement('a')
    link.setAttribute('href', `#${header.getAttribute('id')}`)
    link.innerHTML = header.innerHTML
    element.appendChild(link)

    hierarchy[hierarchy.length - 1].appendChild(element)
  }

  return hierarchy[0]
}

function walkHeaders (element, headers = []) {
  for (const child of element.childNodes) {