// Create a function that will handle any intersection between some elements and the viewport.

const handleFooterIntersection = function (entries) {

  // Loop through all the observed elements

  entries.forEach(entry => {      // Check if the element is intersecting the viewport

      if (entry.isIntersecting) {

        msgConsole('IntersectionObserver','The footer is visible in the viewport');

        if (typeof footerIsNowVisible === 'function') footerIsNowVisible(entry);

      } else {

        msgConsole('IntersectionObserver','The footer is invisible in the viewport');

        if (typeof footerIsNowInvisible === 'function') footerIsNowInvisible(entry);

      }

  });

}

const section_footer = document.querySelector("#footer");

if (section_footer) {

  const footerObserver = new IntersectionObserver(handleFooterIntersection);

  if (footerObserver) footerObserver.observe(section_footer);

} else myLog('No footer to observe');