Proyectos de Subversion LeadersLinked - Antes de SPA

import { useState, useRef, useEffect } from 'react'

export const useNear = ({ rootMargin = '0px' }) => {
  const [isNear, setIsNear] = useState(false)
  const el = useRef(null)

  useEffect(
    function () {
      if (typeof el.current === 'undefined') return

      let observer
      Promise.resolve(
        typeof window.IntersectionObserver !== 'undefined'
          ? window.IntersectionObserver
          : import('intersection-observer')
      ).then(() => {
        const onIntersect = (entries, observer) => {
          const { isIntersecting } = entries[0]

          if (isIntersecting) {
            setIsNear(true)
            observer.disconnect()
          }
        }

        observer = new window.IntersectionObserver(onIntersect, { rootMargin })
        observer.observe(el.current)
      })

      return () => observer && observer.disconnect()
    },
    [el, rootMargin]
  )

  return [isNear, el]
}