ahooks/lib/useInViewport/index.js

react hooks library

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");
Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = void 0;
var _slicedToArray2 = _interopRequireDefault(require("@babel/runtime/helpers/slicedToArray"));
var _tslib = require("tslib");
var _react = require("react");
var _domTarget = require("../utils/domTarget");
var _useEffectWithTarget = _interopRequireDefault(require("../utils/useEffectWithTarget"));
function _createForOfIteratorHelper(r, e) { var t = "undefined" != typeof Symbol && r[Symbol.iterator] || r["@@iterator"]; if (!t) { if (Array.isArray(r) || (t = _unsupportedIterableToArray(r)) || e && r && "number" == typeof r.length) { t && (r = t); var _n = 0, F = function F() {}; return { s: F, n: function n() { return _n >= r.length ? { done: !0 } : { done: !1, value: r[_n++] }; }, e: function e(r) { throw r; }, f: F }; } throw new TypeError("Invalid attempt to iterate non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); } var o, a = !0, u = !1; return { s: function s() { t = t.call(r); }, n: function n() { var r = t.next(); return a = r.done, r; }, e: function e(r) { u = !0, o = r; }, f: function f() { try { a || null == t["return"] || t["return"](); } finally { if (u) throw o; } } }; }
function _unsupportedIterableToArray(r, a) { if (r) { if ("string" == typeof r) return _arrayLikeToArray(r, a); var t = {}.toString.call(r).slice(8, -1); return "Object" === t && r.constructor && (t = r.constructor.name), "Map" === t || "Set" === t ? Array.from(r) : "Arguments" === t || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(t) ? _arrayLikeToArray(r, a) : void 0; } }
function _arrayLikeToArray(r, a) { (null == a || a > r.length) && (a = r.length); for (var e = 0, n = Array(a); e < a; e++) n[e] = r[e]; return n; }
function useInViewport(target, options) {
  var _a = options || {},
    callback = _a.callback,
    option = (0, _tslib.__rest)(_a, ["callback"]);
  var _useState = (0, _react.useState)(),
    _useState2 = (0, _slicedToArray2["default"])(_useState, 2),
    state = _useState2[0],
    setState = _useState2[1];
  var _useState3 = (0, _react.useState)(),
    _useState4 = (0, _slicedToArray2["default"])(_useState3, 2),
    ratio = _useState4[0],
    setRatio = _useState4[1];
  (0, _useEffectWithTarget["default"])(function () {
    var targets = Array.isArray(target) ? target : [target];
    var els = targets.map(function (element) {
      return (0, _domTarget.getTargetElement)(element);
    }).filter(Boolean);
    if (!els.length) {
      return;
    }
    var observer = new IntersectionObserver(function (entries) {
      var _iterator = _createForOfIteratorHelper(entries),
        _step;
      try {
        for (_iterator.s(); !(_step = _iterator.n()).done;) {
          var entry = _step.value;
          setRatio(entry.intersectionRatio);
          setState(entry.isIntersecting);
          callback === null || callback === void 0 ? void 0 : callback(entry);
        }
      } catch (err) {
        _iterator.e(err);
      } finally {
        _iterator.f();
      }
    }, Object.assign(Object.assign({}, option), {
      root: (0, _domTarget.getTargetElement)(options === null || options === void 0 ? void 0 : options.root)
    }));
    els.forEach(function (el) {
      return observer.observe(el);
    });
    return function () {
      observer.disconnect();
    };
  }, [options === null || options === void 0 ? void 0 : options.rootMargin, options === null || options === void 0 ? void 0 : options.threshold, callback], target);
  return [state, ratio];
}
var _default = exports["default"] = useInViewport;