802 lines
24 KiB
JavaScript
802 lines
24 KiB
JavaScript
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const runningOnBrowser = typeof window !== "undefined";
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const isBot =
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(runningOnBrowser && !("onscroll" in window)) ||
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(typeof navigator !== "undefined" && /(gle|ing|ro)bot|crawl|spider/i.test(navigator.userAgent));
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const supportsIntersectionObserver = runningOnBrowser && "IntersectionObserver" in window;
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const supportsClassList = runningOnBrowser && "classList" in document.createElement("p");
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const isHiDpi = runningOnBrowser && window.devicePixelRatio > 1;
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const defaultSettings = {
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elements_selector: ".lazy",
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container: isBot || runningOnBrowser ? document : null,
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threshold: 300,
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thresholds: null,
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data_src: "src",
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data_srcset: "srcset",
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data_sizes: "sizes",
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data_bg: "bg",
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data_bg_hidpi: "bg-hidpi",
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data_bg_multi: "bg-multi",
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data_bg_multi_hidpi: "bg-multi-hidpi",
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data_bg_set: "bg-set",
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data_poster: "poster",
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class_applied: "applied",
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class_loading: "loading",
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class_loaded: "loaded",
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class_error: "error",
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class_entered: "entered",
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class_exited: "exited",
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unobserve_completed: true,
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unobserve_entered: false,
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cancel_on_exit: true,
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callback_enter: null,
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callback_exit: null,
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callback_applied: null,
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callback_loading: null,
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callback_loaded: null,
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callback_error: null,
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callback_finish: null,
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callback_cancel: null,
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use_native: false,
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restore_on_error: false,
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};
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const getExtendedSettings = (customSettings) => {
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return Object.assign({}, defaultSettings, customSettings);
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};
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/* Creates instance and notifies it through the window element */
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const createInstance = function(classObj, options) {
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let event;
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const eventString = "LazyLoad::Initialized";
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const instance = new classObj(options);
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try {
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// Works in modern browsers
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event = new CustomEvent(eventString, { detail: { instance } });
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} catch (err) {
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// Works in Internet Explorer (all versions)
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event = document.createEvent("CustomEvent");
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event.initCustomEvent(eventString, false, false, { instance });
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}
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window.dispatchEvent(event);
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};
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/* Auto initialization of one or more instances of lazyload, depending on the
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options passed in (plain object or an array) */
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const autoInitialize = (classObj, options) => {
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if (!options) {
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return;
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}
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if (!options.length) {
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// Plain object
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createInstance(classObj, options);
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} else {
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// Array of objects
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for (let i = 0, optionsItem; (optionsItem = options[i]); i += 1) {
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createInstance(classObj, optionsItem);
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}
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}
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};
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const SRC = "src";
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const SRCSET = "srcset";
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const SIZES = "sizes";
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const POSTER = "poster";
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const ORIGINALS = "llOriginalAttrs";
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const DATA = "data";
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const statusLoading = "loading";
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const statusLoaded = "loaded";
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const statusApplied = "applied";
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const statusEntered = "entered";
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const statusError = "error";
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const statusNative = "native";
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const dataPrefix = "data-";
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const statusDataName = "ll-status";
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const getData = (element, attribute) => {
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return element.getAttribute(dataPrefix + attribute);
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};
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const setData = (element, attribute, value) => {
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var attrName = dataPrefix + attribute;
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if (value === null) {
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element.removeAttribute(attrName);
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return;
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}
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element.setAttribute(attrName, value);
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};
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const getStatus = (element) => getData(element, statusDataName);
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const setStatus = (element, status) => setData(element, statusDataName, status);
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const resetStatus = (element) => setStatus(element, null);
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const hasEmptyStatus = (element) => getStatus(element) === null;
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const hasStatusLoading = (element) => getStatus(element) === statusLoading;
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const hasStatusError = (element) => getStatus(element) === statusError;
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const hasStatusNative = (element) => getStatus(element) === statusNative;
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const statusesAfterLoading = [statusLoading, statusLoaded, statusApplied, statusError];
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const hadStartedLoading = (element) => statusesAfterLoading.indexOf(getStatus(element)) >= 0;
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const safeCallback = (callback, arg1, arg2, arg3) => {
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if (!callback) {
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return;
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}
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if (arg3 !== undefined) {
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callback(arg1, arg2, arg3);
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return;
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}
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if (arg2 !== undefined) {
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callback(arg1, arg2);
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return;
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}
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callback(arg1);
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};
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const addClass = (element, className) => {
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if (supportsClassList) {
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element.classList.add(className);
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return;
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}
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element.className += (element.className ? " " : "") + className;
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};
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const removeClass = (element, className) => {
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if (supportsClassList) {
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element.classList.remove(className);
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return;
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}
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element.className = element.className.
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replace(new RegExp("(^|\\s+)" + className + "(\\s+|$)"), " ").
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replace(/^\s+/, "").
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replace(/\s+$/, "");
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};
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const addTempImage = (element) => {
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element.llTempImage = document.createElement("IMG");
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};
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const deleteTempImage = (element) => {
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delete element.llTempImage;
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};
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const getTempImage = (element) => element.llTempImage;
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const unobserve = (element, instance) => {
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if (!instance) return;
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const observer = instance._observer;
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if (!observer) return;
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observer.unobserve(element);
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};
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const resetObserver = (observer) => {
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observer.disconnect();
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};
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const unobserveEntered = (element, settings, instance) => {
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if (settings.unobserve_entered) unobserve(element, instance);
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};
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const updateLoadingCount = (instance, delta) => {
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if (!instance) return;
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instance.loadingCount += delta;
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};
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const decreaseToLoadCount = (instance) => {
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if (!instance) return;
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instance.toLoadCount -= 1;
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};
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const setToLoadCount = (instance, value) => {
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if (!instance) return;
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instance.toLoadCount = value;
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};
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const isSomethingLoading = (instance) => instance.loadingCount > 0;
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const haveElementsToLoad = (instance) => instance.toLoadCount > 0;
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const getSourceTags = (parentTag) => {
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let sourceTags = [];
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for (let i = 0, childTag; (childTag = parentTag.children[i]); i += 1) {
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if (childTag.tagName === "SOURCE") {
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sourceTags.push(childTag);
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}
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}
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return sourceTags;
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};
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const forEachPictureSource = (element, fn) => {
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const parent = element.parentNode;
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if (!parent || parent.tagName !== "PICTURE") {
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return;
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}
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let sourceTags = getSourceTags(parent);
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sourceTags.forEach(fn);
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};
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const forEachVideoSource = (element, fn) => {
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let sourceTags = getSourceTags(element);
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sourceTags.forEach(fn);
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};
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const attrsSrc = [SRC];
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const attrsSrcPoster = [SRC, POSTER];
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const attrsSrcSrcsetSizes = [SRC, SRCSET, SIZES];
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const attrsData = [DATA];
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const hasOriginalAttrs = (element) => !!element[ORIGINALS];
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const getOriginalAttrs = (element) => element[ORIGINALS];
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const deleteOriginalAttrs = (element) => delete element[ORIGINALS];
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// ## SAVE ##
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const setOriginalsObject = (element, attributes) => {
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if (hasOriginalAttrs(element)) {
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return;
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}
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const originals = {};
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attributes.forEach((attribute) => {
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originals[attribute] = element.getAttribute(attribute);
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});
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element[ORIGINALS] = originals;
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};
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const saveOriginalBackgroundStyle = (element) => {
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if (hasOriginalAttrs(element)) {
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return;
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}
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element[ORIGINALS] = { backgroundImage: element.style.backgroundImage };
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};
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// ## RESTORE ##
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const setOrResetAttribute = (element, attrName, value) => {
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if (!value) {
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element.removeAttribute(attrName);
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return;
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}
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element.setAttribute(attrName, value);
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};
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const restoreOriginalAttrs = (element, attributes) => {
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if (!hasOriginalAttrs(element)) {
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return;
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}
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const originals = getOriginalAttrs(element);
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attributes.forEach((attribute) => {
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setOrResetAttribute(element, attribute, originals[attribute]);
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});
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};
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const restoreOriginalBgImage = (element) => {
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if (!hasOriginalAttrs(element)) {
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return;
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}
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const originals = getOriginalAttrs(element);
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element.style.backgroundImage = originals.backgroundImage;
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};
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const manageApplied = (element, settings, instance) => {
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addClass(element, settings.class_applied);
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setStatus(element, statusApplied);
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// Instance is not provided when loading is called from static class
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if (!instance) return;
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if (settings.unobserve_completed) {
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// Unobserve now because we can't do it on load
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unobserve(element, settings);
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}
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safeCallback(settings.callback_applied, element, instance);
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};
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const manageLoading = (element, settings, instance) => {
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addClass(element, settings.class_loading);
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setStatus(element, statusLoading);
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// Instance is not provided when loading is called from static class
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if (!instance) return;
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updateLoadingCount(instance, +1);
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safeCallback(settings.callback_loading, element, instance);
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};
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const setAttributeIfValue = (element, attrName, value) => {
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if (!value) {
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return;
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}
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element.setAttribute(attrName, value);
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};
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const setImageAttributes = (element, settings) => {
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setAttributeIfValue(element, SIZES, getData(element, settings.data_sizes));
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setAttributeIfValue(element, SRCSET, getData(element, settings.data_srcset));
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setAttributeIfValue(element, SRC, getData(element, settings.data_src));
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};
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const setSourcesImg = (imgEl, settings) => {
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forEachPictureSource(imgEl, (sourceTag) => {
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setOriginalsObject(sourceTag, attrsSrcSrcsetSizes);
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setImageAttributes(sourceTag, settings);
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});
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setOriginalsObject(imgEl, attrsSrcSrcsetSizes);
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setImageAttributes(imgEl, settings);
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};
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const setSourcesIframe = (iframe, settings) => {
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setOriginalsObject(iframe, attrsSrc);
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setAttributeIfValue(iframe, SRC, getData(iframe, settings.data_src));
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};
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const setSourcesVideo = (videoEl, settings) => {
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forEachVideoSource(videoEl, (sourceEl) => {
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setOriginalsObject(sourceEl, attrsSrc);
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setAttributeIfValue(sourceEl, SRC, getData(sourceEl, settings.data_src));
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});
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setOriginalsObject(videoEl, attrsSrcPoster);
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setAttributeIfValue(videoEl, POSTER, getData(videoEl, settings.data_poster));
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setAttributeIfValue(videoEl, SRC, getData(videoEl, settings.data_src));
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videoEl.load();
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};
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const setSourcesObject = (object, settings) => {
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setOriginalsObject(object, attrsData);
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setAttributeIfValue(object, DATA, getData(object, settings.data_src));
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};
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const setBackground = (element, settings, instance) => {
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const bg1xValue = getData(element, settings.data_bg);
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const bgHiDpiValue = getData(element, settings.data_bg_hidpi);
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const bgDataValue = isHiDpi && bgHiDpiValue ? bgHiDpiValue : bg1xValue;
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if (!bgDataValue) return;
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element.style.backgroundImage = `url("${bgDataValue}")`;
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getTempImage(element).setAttribute(SRC, bgDataValue);
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manageLoading(element, settings, instance);
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};
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// NOTE: THE TEMP IMAGE TRICK CANNOT BE DONE WITH data-multi-bg
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// BECAUSE INSIDE ITS VALUES MUST BE WRAPPED WITH URL() AND ONE OF THEM
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// COULD BE A GRADIENT BACKGROUND IMAGE
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const setMultiBackground = (element, settings, instance) => {
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const bg1xValue = getData(element, settings.data_bg_multi);
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const bgHiDpiValue = getData(element, settings.data_bg_multi_hidpi);
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const bgDataValue = isHiDpi && bgHiDpiValue ? bgHiDpiValue : bg1xValue;
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if (!bgDataValue) {
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return;
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}
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element.style.backgroundImage = bgDataValue;
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manageApplied(element, settings, instance);
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};
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const setImgsetBackground = (element, settings, instance) => {
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const bgImgSetDataValue = getData(element, settings.data_bg_set);
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if (!bgImgSetDataValue) {
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return;
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}
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const imgSetValues = bgImgSetDataValue.split("|");
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|
|
let bgImageValues = imgSetValues.map((value) => `image-set(${value})`);
|
||
|
|
element.style.backgroundImage = bgImageValues.join();
|
||
|
|
// Temporary fix for Chromeium with the -webkit- prefix
|
||
|
|
if (element.style.backgroundImage === '') {
|
||
|
|
bgImageValues = imgSetValues.map((value) => `-webkit-image-set(${value})`);
|
||
|
|
element.style.backgroundImage = bgImageValues.join();
|
||
|
|
}
|
||
|
|
manageApplied(element, settings, instance);
|
||
|
|
};
|
||
|
|
|
||
|
|
const setSourcesFunctions = {
|
||
|
|
IMG: setSourcesImg,
|
||
|
|
IFRAME: setSourcesIframe,
|
||
|
|
VIDEO: setSourcesVideo,
|
||
|
|
OBJECT: setSourcesObject
|
||
|
|
};
|
||
|
|
|
||
|
|
const setSourcesNative = (element, settings) => {
|
||
|
|
const setSourcesFunction = setSourcesFunctions[element.tagName];
|
||
|
|
if (!setSourcesFunction) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
setSourcesFunction(element, settings);
|
||
|
|
};
|
||
|
|
|
||
|
|
const setSources = (element, settings, instance) => {
|
||
|
|
const setSourcesFunction = setSourcesFunctions[element.tagName];
|
||
|
|
if (!setSourcesFunction) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
setSourcesFunction(element, settings);
|
||
|
|
manageLoading(element, settings, instance);
|
||
|
|
};
|
||
|
|
|
||
|
|
const elementsWithLoadEvent = ["IMG", "IFRAME", "VIDEO", "OBJECT"];
|
||
|
|
const hasLoadEvent = (element) => elementsWithLoadEvent.indexOf(element.tagName) > -1;
|
||
|
|
|
||
|
|
const checkFinish = (settings, instance) => {
|
||
|
|
if (instance && !isSomethingLoading(instance) && !haveElementsToLoad(instance)) {
|
||
|
|
safeCallback(settings.callback_finish, instance);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
const addEventListener = (element, eventName, handler) => {
|
||
|
|
element.addEventListener(eventName, handler);
|
||
|
|
element.llEvLisnrs[eventName] = handler;
|
||
|
|
};
|
||
|
|
|
||
|
|
const removeEventListener = (element, eventName, handler) => {
|
||
|
|
element.removeEventListener(eventName, handler);
|
||
|
|
};
|
||
|
|
|
||
|
|
const hasEventListeners = (element) => {
|
||
|
|
return !!element.llEvLisnrs;
|
||
|
|
};
|
||
|
|
|
||
|
|
const addEventListeners = (element, loadHandler, errorHandler) => {
|
||
|
|
if (!hasEventListeners(element)) element.llEvLisnrs = {};
|
||
|
|
const loadEventName = element.tagName === "VIDEO" ? "loadeddata" : "load";
|
||
|
|
addEventListener(element, loadEventName, loadHandler);
|
||
|
|
addEventListener(element, "error", errorHandler);
|
||
|
|
};
|
||
|
|
|
||
|
|
const removeEventListeners = (element) => {
|
||
|
|
if (!hasEventListeners(element)) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
const eventListeners = element.llEvLisnrs;
|
||
|
|
for (let eventName in eventListeners) {
|
||
|
|
const handler = eventListeners[eventName];
|
||
|
|
removeEventListener(element, eventName, handler);
|
||
|
|
}
|
||
|
|
delete element.llEvLisnrs;
|
||
|
|
};
|
||
|
|
|
||
|
|
const doneHandler = (element, settings, instance) => {
|
||
|
|
deleteTempImage(element);
|
||
|
|
updateLoadingCount(instance, -1);
|
||
|
|
decreaseToLoadCount(instance);
|
||
|
|
removeClass(element, settings.class_loading);
|
||
|
|
if (settings.unobserve_completed) {
|
||
|
|
unobserve(element, instance);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
const loadHandler = (event, element, settings, instance) => {
|
||
|
|
const goingNative = hasStatusNative(element);
|
||
|
|
doneHandler(element, settings, instance);
|
||
|
|
addClass(element, settings.class_loaded);
|
||
|
|
setStatus(element, statusLoaded);
|
||
|
|
safeCallback(settings.callback_loaded, element, instance);
|
||
|
|
if (!goingNative) checkFinish(settings, instance);
|
||
|
|
};
|
||
|
|
|
||
|
|
const errorHandler = (event, element, settings, instance) => {
|
||
|
|
const goingNative = hasStatusNative(element);
|
||
|
|
doneHandler(element, settings, instance);
|
||
|
|
addClass(element, settings.class_error);
|
||
|
|
setStatus(element, statusError);
|
||
|
|
safeCallback(settings.callback_error, element, instance);
|
||
|
|
if (settings.restore_on_error) restoreOriginalAttrs(element, attrsSrcSrcsetSizes);
|
||
|
|
if (!goingNative) checkFinish(settings, instance);
|
||
|
|
};
|
||
|
|
|
||
|
|
const addOneShotEventListeners = (element, settings, instance) => {
|
||
|
|
const elementToListenTo = getTempImage(element) || element;
|
||
|
|
if (hasEventListeners(elementToListenTo)) {
|
||
|
|
// This happens when loading is retried twice
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
const _loadHandler = (event) => {
|
||
|
|
loadHandler(event, element, settings, instance);
|
||
|
|
removeEventListeners(elementToListenTo);
|
||
|
|
};
|
||
|
|
const _errorHandler = (event) => {
|
||
|
|
errorHandler(event, element, settings, instance);
|
||
|
|
removeEventListeners(elementToListenTo);
|
||
|
|
};
|
||
|
|
addEventListeners(elementToListenTo, _loadHandler, _errorHandler);
|
||
|
|
};
|
||
|
|
|
||
|
|
const loadBackground = (element, settings, instance) => {
|
||
|
|
addTempImage(element);
|
||
|
|
addOneShotEventListeners(element, settings, instance);
|
||
|
|
saveOriginalBackgroundStyle(element);
|
||
|
|
setBackground(element, settings, instance);
|
||
|
|
setMultiBackground(element, settings, instance);
|
||
|
|
setImgsetBackground(element, settings, instance);
|
||
|
|
};
|
||
|
|
|
||
|
|
const loadRegular = (element, settings, instance) => {
|
||
|
|
addOneShotEventListeners(element, settings, instance);
|
||
|
|
setSources(element, settings, instance);
|
||
|
|
};
|
||
|
|
|
||
|
|
const load = (element, settings, instance) => {
|
||
|
|
if (hasLoadEvent(element)) {
|
||
|
|
loadRegular(element, settings, instance);
|
||
|
|
} else {
|
||
|
|
loadBackground(element, settings, instance);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
const loadNative = (element, settings, instance) => {
|
||
|
|
element.setAttribute("loading", "lazy");
|
||
|
|
addOneShotEventListeners(element, settings, instance);
|
||
|
|
setSourcesNative(element, settings);
|
||
|
|
setStatus(element, statusNative);
|
||
|
|
};
|
||
|
|
|
||
|
|
const removeImageAttributes = (element) => {
|
||
|
|
element.removeAttribute(SRC);
|
||
|
|
element.removeAttribute(SRCSET);
|
||
|
|
element.removeAttribute(SIZES);
|
||
|
|
};
|
||
|
|
|
||
|
|
const resetSourcesImg = (element) => {
|
||
|
|
forEachPictureSource(element, (sourceTag) => {
|
||
|
|
removeImageAttributes(sourceTag);
|
||
|
|
});
|
||
|
|
removeImageAttributes(element);
|
||
|
|
};
|
||
|
|
|
||
|
|
const restoreImg = (imgEl) => {
|
||
|
|
forEachPictureSource(imgEl, (sourceEl) => {
|
||
|
|
restoreOriginalAttrs(sourceEl, attrsSrcSrcsetSizes);
|
||
|
|
});
|
||
|
|
restoreOriginalAttrs(imgEl, attrsSrcSrcsetSizes);
|
||
|
|
};
|
||
|
|
|
||
|
|
const restoreVideo = (videoEl) => {
|
||
|
|
forEachVideoSource(videoEl, (sourceEl) => {
|
||
|
|
restoreOriginalAttrs(sourceEl, attrsSrc);
|
||
|
|
});
|
||
|
|
restoreOriginalAttrs(videoEl, attrsSrcPoster);
|
||
|
|
videoEl.load();
|
||
|
|
};
|
||
|
|
|
||
|
|
const restoreIframe = (iframeEl) => {
|
||
|
|
restoreOriginalAttrs(iframeEl, attrsSrc);
|
||
|
|
};
|
||
|
|
|
||
|
|
const restoreObject = (objectEl) => {
|
||
|
|
restoreOriginalAttrs(objectEl, attrsData);
|
||
|
|
};
|
||
|
|
|
||
|
|
const restoreFunctions = {
|
||
|
|
IMG: restoreImg,
|
||
|
|
IFRAME: restoreIframe,
|
||
|
|
VIDEO: restoreVideo,
|
||
|
|
OBJECT: restoreObject
|
||
|
|
};
|
||
|
|
|
||
|
|
const restoreAttributes = (element) => {
|
||
|
|
const restoreFunction = restoreFunctions[element.tagName];
|
||
|
|
if (!restoreFunction) {
|
||
|
|
restoreOriginalBgImage(element);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
restoreFunction(element);
|
||
|
|
};
|
||
|
|
|
||
|
|
const resetClasses = (element, settings) => {
|
||
|
|
if (hasEmptyStatus(element) || hasStatusNative(element)) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
removeClass(element, settings.class_entered);
|
||
|
|
removeClass(element, settings.class_exited);
|
||
|
|
removeClass(element, settings.class_applied);
|
||
|
|
removeClass(element, settings.class_loading);
|
||
|
|
removeClass(element, settings.class_loaded);
|
||
|
|
removeClass(element, settings.class_error);
|
||
|
|
};
|
||
|
|
|
||
|
|
const restore = (element, settings) => {
|
||
|
|
restoreAttributes(element);
|
||
|
|
resetClasses(element, settings);
|
||
|
|
resetStatus(element);
|
||
|
|
deleteOriginalAttrs(element);
|
||
|
|
};
|
||
|
|
|
||
|
|
const cancelLoading = (element, entry, settings, instance) => {
|
||
|
|
if (!settings.cancel_on_exit) return;
|
||
|
|
if (!hasStatusLoading(element)) return;
|
||
|
|
if (element.tagName !== "IMG") return; //Works only on images
|
||
|
|
removeEventListeners(element);
|
||
|
|
resetSourcesImg(element);
|
||
|
|
restoreImg(element);
|
||
|
|
removeClass(element, settings.class_loading);
|
||
|
|
updateLoadingCount(instance, -1);
|
||
|
|
resetStatus(element);
|
||
|
|
safeCallback(settings.callback_cancel, element, entry, instance);
|
||
|
|
};
|
||
|
|
|
||
|
|
const onEnter = (element, entry, settings, instance) => {
|
||
|
|
const dontLoad = hadStartedLoading(element); /* Save status
|
||
|
|
before setting it, to prevent loading it again. Fixes #526. */
|
||
|
|
setStatus(element, statusEntered);
|
||
|
|
addClass(element, settings.class_entered);
|
||
|
|
removeClass(element, settings.class_exited);
|
||
|
|
unobserveEntered(element, settings, instance);
|
||
|
|
safeCallback(settings.callback_enter, element, entry, instance);
|
||
|
|
if (dontLoad) return;
|
||
|
|
load(element, settings, instance);
|
||
|
|
};
|
||
|
|
|
||
|
|
const onExit = (element, entry, settings, instance) => {
|
||
|
|
if (hasEmptyStatus(element)) return; //Ignore the first pass, at landing
|
||
|
|
addClass(element, settings.class_exited);
|
||
|
|
cancelLoading(element, entry, settings, instance);
|
||
|
|
safeCallback(settings.callback_exit, element, entry, instance);
|
||
|
|
};
|
||
|
|
|
||
|
|
const tagsWithNativeLazy = ["IMG", "IFRAME", "VIDEO"];
|
||
|
|
|
||
|
|
const shouldUseNative = (settings) =>
|
||
|
|
settings.use_native && "loading" in HTMLImageElement.prototype;
|
||
|
|
|
||
|
|
const loadAllNative = (elements, settings, instance) => {
|
||
|
|
elements.forEach((element) => {
|
||
|
|
if (tagsWithNativeLazy.indexOf(element.tagName) === -1) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
loadNative(element, settings, instance);
|
||
|
|
});
|
||
|
|
setToLoadCount(instance, 0);
|
||
|
|
};
|
||
|
|
|
||
|
|
const isIntersecting = (entry) => entry.isIntersecting || entry.intersectionRatio > 0;
|
||
|
|
|
||
|
|
const getObserverSettings = (settings) => ({
|
||
|
|
root: settings.container === document ? null : settings.container,
|
||
|
|
rootMargin: settings.thresholds || settings.threshold + "px"
|
||
|
|
});
|
||
|
|
|
||
|
|
const intersectionHandler = (entries, settings, instance) => {
|
||
|
|
entries.forEach((entry) =>
|
||
|
|
isIntersecting(entry)
|
||
|
|
? onEnter(entry.target, entry, settings, instance)
|
||
|
|
: onExit(entry.target, entry, settings, instance)
|
||
|
|
);
|
||
|
|
};
|
||
|
|
|
||
|
|
const observeElements = (observer, elements) => {
|
||
|
|
elements.forEach((element) => {
|
||
|
|
observer.observe(element);
|
||
|
|
});
|
||
|
|
};
|
||
|
|
|
||
|
|
const updateObserver = (observer, elementsToObserve) => {
|
||
|
|
resetObserver(observer);
|
||
|
|
observeElements(observer, elementsToObserve);
|
||
|
|
};
|
||
|
|
|
||
|
|
const setObserver = (settings, instance) => {
|
||
|
|
if (!supportsIntersectionObserver || shouldUseNative(settings)) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
instance._observer = new IntersectionObserver((entries) => {
|
||
|
|
intersectionHandler(entries, settings, instance);
|
||
|
|
}, getObserverSettings(settings));
|
||
|
|
};
|
||
|
|
|
||
|
|
const toArray = (nodeSet) => Array.prototype.slice.call(nodeSet);
|
||
|
|
|
||
|
|
const queryElements = (settings) =>
|
||
|
|
settings.container.querySelectorAll(settings.elements_selector);
|
||
|
|
|
||
|
|
const excludeManagedElements = (elements) => toArray(elements).filter(hasEmptyStatus);
|
||
|
|
|
||
|
|
const hasError = (element) => hasStatusError(element);
|
||
|
|
const filterErrorElements = (elements) => toArray(elements).filter(hasError);
|
||
|
|
|
||
|
|
const getElementsToLoad = (elements, settings) =>
|
||
|
|
excludeManagedElements(elements || queryElements(settings));
|
||
|
|
|
||
|
|
const retryLazyLoad = (settings, instance) => {
|
||
|
|
const errorElements = filterErrorElements(queryElements(settings));
|
||
|
|
errorElements.forEach((element) => {
|
||
|
|
removeClass(element, settings.class_error);
|
||
|
|
resetStatus(element);
|
||
|
|
});
|
||
|
|
instance.update();
|
||
|
|
};
|
||
|
|
|
||
|
|
const setOnlineCheck = (settings, instance) => {
|
||
|
|
if (!runningOnBrowser) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
instance._onlineHandler = () => {
|
||
|
|
retryLazyLoad(settings, instance);
|
||
|
|
};
|
||
|
|
window.addEventListener("online", instance._onlineHandler);
|
||
|
|
};
|
||
|
|
|
||
|
|
const resetOnlineCheck = (instance) => {
|
||
|
|
if (!runningOnBrowser) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
window.removeEventListener("online", instance._onlineHandler);
|
||
|
|
};
|
||
|
|
|
||
|
|
const LazyLoad = function (customSettings, elements) {
|
||
|
|
const settings = getExtendedSettings(customSettings);
|
||
|
|
this._settings = settings;
|
||
|
|
this.loadingCount = 0;
|
||
|
|
setObserver(settings, this);
|
||
|
|
setOnlineCheck(settings, this);
|
||
|
|
this.update(elements);
|
||
|
|
};
|
||
|
|
|
||
|
|
LazyLoad.prototype = {
|
||
|
|
update: function (givenNodeset) {
|
||
|
|
const settings = this._settings;
|
||
|
|
const elementsToLoad = getElementsToLoad(givenNodeset, settings);
|
||
|
|
setToLoadCount(this, elementsToLoad.length);
|
||
|
|
|
||
|
|
if (isBot || !supportsIntersectionObserver) {
|
||
|
|
this.loadAll(elementsToLoad);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
if (shouldUseNative(settings)) {
|
||
|
|
loadAllNative(elementsToLoad, settings, this);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
updateObserver(this._observer, elementsToLoad);
|
||
|
|
},
|
||
|
|
|
||
|
|
destroy: function () {
|
||
|
|
// Observer
|
||
|
|
if (this._observer) {
|
||
|
|
this._observer.disconnect();
|
||
|
|
}
|
||
|
|
// Clean handlers
|
||
|
|
resetOnlineCheck(this);
|
||
|
|
// Clean custom attributes on elements
|
||
|
|
queryElements(this._settings).forEach((element) => {
|
||
|
|
deleteOriginalAttrs(element);
|
||
|
|
});
|
||
|
|
// Delete all internal props
|
||
|
|
delete this._observer;
|
||
|
|
delete this._settings;
|
||
|
|
delete this._onlineHandler;
|
||
|
|
delete this.loadingCount;
|
||
|
|
delete this.toLoadCount;
|
||
|
|
},
|
||
|
|
|
||
|
|
loadAll: function (elements) {
|
||
|
|
const settings = this._settings;
|
||
|
|
const elementsToLoad = getElementsToLoad(elements, settings);
|
||
|
|
elementsToLoad.forEach((element) => {
|
||
|
|
unobserve(element, this);
|
||
|
|
load(element, settings, this);
|
||
|
|
});
|
||
|
|
},
|
||
|
|
|
||
|
|
restoreAll: function() {
|
||
|
|
const settings = this._settings;
|
||
|
|
queryElements(settings).forEach((element) => {
|
||
|
|
restore(element, settings);
|
||
|
|
});
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
LazyLoad.load = (element, customSettings) => {
|
||
|
|
const settings = getExtendedSettings(customSettings);
|
||
|
|
load(element, settings);
|
||
|
|
};
|
||
|
|
|
||
|
|
LazyLoad.resetStatus = (element) => {
|
||
|
|
resetStatus(element);
|
||
|
|
};
|
||
|
|
|
||
|
|
// Automatic instances creation if required (useful for async script loading)
|
||
|
|
if (runningOnBrowser) {
|
||
|
|
autoInitialize(LazyLoad, window.lazyLoadOptions);
|
||
|
|
}
|
||
|
|
|
||
|
|
export { LazyLoad as default };
|