Intersection observer calling function at wrong time

Question

when i run the page the intersection observer works just like i want but when i reload the page it teleports me back up to the page(ok thats normal) but then when the viewport is event interacting with the target it calls the function immidiatley. Btw im using vuejs in the project if this has anything to with it

let options = {
  root: null,
  rootMargin: "-20px",
  threshold: 0.375,
};
const widths = ["w-1/3", "w-4/5", "w-1/2", "w-1/2", "w-1/2", "w-2/4", "w-1/2"];
function callback(entries) {
  entries.forEach((entry) => {
    // Each entry describes an intersection change for one observed
    // target element:
    //   entry.boundingClientRect
    //   entry.intersectionRatio
    //   entry.intersectionRect
    //   entry.isIntersecting
    //   entry.rootBounds
    //   entry.target
    //   entry.time
  });
  console.log(entries);
  const entry = entries[0];
  if (entry.isIntersecting === true) {
    document.querySelectorAll(".bar-inner").forEach((el, i) => {
      widths.forEach((w, j) => {
        if (i === j) {
          el.classList.remove("w-0");
          el.classList.add(w);
        }
      });
    });
  }
}

let observer = new IntersectionObserver(callback, options);
const tg = document.getElementById("section2");
observer.observe(tg);

Edit: i called the intersection observer function when window loads so the problem is solved — 234wpm, Apr 18 '23 at 14:49

score 0 · Accepted Answer · answered Apr 13 '23 at 02:57

It seems that when you reload the page, the page is scrolling from where it was to the top. Thus, observer is getting triggered. This may be happening due to PWA service workers. You need to handle this case separately. For inspiration, you can look at - Refresh Page and Keep Scroll Position

Intersection observer calling function at wrong time

1 Answers1