@kiwicom/orbit-components/es/hooks/useIntersect/index.js

Orbit-components is a React component library which provides developers with the easiest possible way of building Kiwi.com’s products.

import _slicedToArray from "@babel/runtime/helpers/esm/slicedToArray";
import { useState, useEffect, useRef } from "react";
export default (function (_ref) {
  var _ref$root = _ref.root,
      root = _ref$root === void 0 ? null : _ref$root,
      rootMargin = _ref.rootMargin,
      _ref$threshold = _ref.threshold,
      threshold = _ref$threshold === void 0 ? 0 : _ref$threshold;

  if (typeof window === "undefined") {
    return {
      ref: null,
      entry: null
    };
  }

  var _useState = useState(null),
      _useState2 = _slicedToArray(_useState, 2),
      entry = _useState2[0],
      updateEntry = _useState2[1];

  var _useState3 = useState(null),
      _useState4 = _slicedToArray(_useState3, 2),
      node = _useState4[0],
      setNode = _useState4[1];

  var observer = useRef(null);
  useEffect(function () {
    observer.current = new window.IntersectionObserver(function (_ref2) {
      var _ref3 = _slicedToArray(_ref2, 1),
          ent = _ref3[0];

      return updateEntry(ent);
    }, {
      root: root,
      rootMargin: rootMargin,
      threshold: threshold
    });
    var currentObs = observer.current;
    if (node) currentObs === null || currentObs === void 0 ? void 0 : currentObs.observe(node);
    return function () {
      return currentObs === null || currentObs === void 0 ? void 0 : currentObs.disconnect();
    };
  }, [node, root, rootMargin, threshold]);
  return {
    ref: setNode,
    entry: entry
  };
});