overleaf/services/web/frontend/js/features/outline/components/outline-root.js

import React from 'react'
import PropTypes from 'prop-types'
import OutlineList from './outline-list'

function OutlineRoot({ outline, jumpToLine, highlightedLine }) {
  return (
    <div>
      {outline.length ? (
        <OutlineList
          outline={outline}
          jumpToLine={jumpToLine}
          isRoot
          highlightedLine={highlightedLine}
        />
      ) : (
        <div className="outline-body-no-elements">
          We can’t find any sections or subsections in this file.{' '}
          <a
            href="/learn/how-to/Using_the_File_Outline_feature"
            className="outline-body-link"
            target="_blank"
            rel="noopener noreferrer"
          >
            Find out more about the file outline
          </a>
        </div>
      )}
    </div>
  )
}

OutlineRoot.propTypes = {
  outline: PropTypes.array.isRequired,
  jumpToLine: PropTypes.func.isRequired,
  highlightedLine: PropTypes.number
}

export default OutlineRoot