baseframe-js/dist/cjs/LazyLoad.js

A suite of useful Javascript plugins and functions to help with Front-end Development on websites

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = void 0;
var _cashDom = _interopRequireDefault(require("cash-dom"));
var _helpers = require("./util/helpers");
var _Store = _interopRequireDefault(require("./core/Store"));
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }
function _typeof(o) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (o) { return typeof o; } : function (o) { return o && "function" == typeof Symbol && o.constructor === Symbol && o !== Symbol.prototype ? "symbol" : typeof o; }, _typeof(o); }
function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, _toPropertyKey(descriptor.key), descriptor); } }
function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); Object.defineProperty(Constructor, "prototype", { writable: false }); return Constructor; }
function _defineProperty(obj, key, value) { key = _toPropertyKey(key); if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
function _toPropertyKey(t) { var i = _toPrimitive(t, "string"); return "symbol" == _typeof(i) ? i : i + ""; }
function _toPrimitive(t, r) { if ("object" != _typeof(t) || !t) return t; var e = t[Symbol.toPrimitive]; if (void 0 !== e) { var i = e.call(t, r || "default"); if ("object" != _typeof(i)) return i; throw new TypeError("@@toPrimitive must return a primitive value."); } return ("string" === r ? String : Number)(t); }
var VERSION = '2.0.1';
var DATA_NAME = 'LazyLoad';
var EVENT_NAME = 'lazyLoad';
var DEFAULTS = {
  imgSrcName: 'src',
  bgSrcName: 'bgSrc',
  loadImgs: true,
  inEvt: null,
  outEvt: null,
  force: false,
  observerID: null,
  unobserve: true,
  observerOpts: {
    rootMargin: '48px'
  }
};
var lazyElemObservers = new Map();
var lazyElemObserver = function lazyElemObserver(s) {
  var observerOpts = s.params.observerOpts;
  return new IntersectionObserver(function (entries) {
    entries.forEach(function (entry) {
      var _s$params = s.params,
        inEvt = _s$params.inEvt,
        outEvt = _s$params.outEvt,
        force = _s$params.force,
        unobserve = _s$params.unobserve,
        loadImgs = _s$params.loadImgs;
      var lazyElem = entry.target;
      if (lazyElem instanceof HTMLElement) {
        if (entry.isIntersecting && (0, _helpers.isVisible)(lazyElem) || force) {
          loadImgs && s.imgAndBg(s, lazyElem);
          typeof inEvt === 'function' && inEvt(lazyElem, entry);
          unobserve && s.lazyElemObserver.unobserve(lazyElem);
        } else {
          typeof outEvt === 'function' && outEvt(lazyElem, entry);
        }
      }
    });
  }, observerOpts);
};
var LazyLoad = exports["default"] = /*#__PURE__*/function () {
  function LazyLoad(element, options) {
    _classCallCheck(this, LazyLoad);
    _defineProperty(this, "element", void 0);
    _defineProperty(this, "params", void 0);
    _defineProperty(this, "lazyElemObserver", void 0);
    var s = this;
    var dataOptions = (0, _helpers.getDataOptions)(element, EVENT_NAME);
    s.element = element;
    s.lazyElemObserver;
    s.params = _cashDom["default"].extend({}, LazyLoad.defaults, options, dataOptions);
    s.handleEvents();
    return s;
  }
  return _createClass(LazyLoad, [{
    key: "imgAndBg",
    value: function imgAndBg(s, lazyElem) {
      var _s$params2 = s.params,
        imgSrcName = _s$params2.imgSrcName,
        bgSrcName = _s$params2.bgSrcName;
      var src = lazyElem.dataset[imgSrcName];
      var bgImg = lazyElem.dataset[bgSrcName];
      if (lazyElem.loading === 'lazy') {
        lazyElem.loading = 'eager';
      }
      if (src) {
        lazyElem.src = src;
      }
      if (bgImg) {
        lazyElem.style.backgroundImage = "url(\"".concat(bgImg, "\")");
        lazyElem.removeAttribute('data-bg-src');
      }
    }
  }, {
    key: "handleEvents",
    value: function handleEvents() {
      var s = this;
      var observerID = s.params.observerID;
      if (observerID && !lazyElemObservers.has(observerID)) {
        lazyElemObservers.set(observerID, lazyElemObserver(s));
        s.lazyElemObserver = lazyElemObservers.get(observerID);
      } else {
        s.lazyElemObserver = lazyElemObserver(s);
      }
      if (!observerID) {
        console.warn("It recommended to set an 'observerID', so the element group can leverage the same one.", s.element);
      }
      s.lazyElemObserver.observe(s.element);
    }
  }], [{
    key: "remove",
    value: function remove(element, plugin) {
      (0, _cashDom["default"])(element).each(function () {
        var s = plugin || (0, _Store["default"])(this, DATA_NAME);
        lazyElemObservers["delete"](s.params.observerID);
        s.lazyElemObserver.unobserve(this);
        (0, _Store["default"])(this, DATA_NAME, null);
      });
    }
  }]);
}();
_defineProperty(LazyLoad, "defaults", DEFAULTS);
_defineProperty(LazyLoad, "version", VERSION);
_defineProperty(LazyLoad, "pluginName", DATA_NAME);