Anxhelo Lushka
7 years ago
committed by
GitHub
GitHub
1 changed files with 301 additions and 0 deletions
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var _extends = Object.assign || function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; }; |
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var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; |
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(function (global, factory) { |
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(typeof exports === 'undefined' ? 'undefined' : _typeof(exports)) === 'object' && typeof module !== 'undefined' ? module.exports = factory() : typeof define === 'function' && define.amd ? define(factory) : global.LazyLoad = factory(); |
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})(this, function () { |
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'use strict'; |
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var getInstanceSettings = function getInstanceSettings(customSettings) { |
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var defaultSettings = { |
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elements_selector: "img", |
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container: document, |
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threshold: 300, |
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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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class_loading: "loading", |
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class_loaded: "loaded", |
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class_error: "error", |
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callback_load: null, |
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callback_error: null, |
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callback_set: null, |
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callback_enter: null |
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}; |
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return _extends({}, defaultSettings, customSettings); |
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}; |
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var dataPrefix = "data-"; |
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var processedDataName = "was-processed"; |
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var processedDataValue = "true"; |
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var getData = function getData(element, attribute) { |
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return element.getAttribute(dataPrefix + attribute); |
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}; |
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var setData = function setData(element, attribute, value) { |
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return element.setAttribute(dataPrefix + attribute, value); |
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}; |
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var setWasProcessed = function setWasProcessed(element) { |
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return setData(element, processedDataName, processedDataValue); |
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}; |
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var getWasProcessed = function getWasProcessed(element) { |
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return getData(element, processedDataName) === processedDataValue; |
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}; |
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function purgeElements(elements) { |
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return elements.filter(function (element) { |
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return !getWasProcessed(element); |
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}); |
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} |
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/* Creates instance and notifies it through the window element */ |
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var createInstance = function createInstance(classObj, options) { |
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var event; |
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var eventString = "LazyLoad::Initialized"; |
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var 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: 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: 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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function autoInitialize(classObj, options) { |
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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 (var 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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var setSourcesInChildren = function setSourcesInChildren(parentTag, attrName, dataAttrName) { |
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for (var i = 0, childTag; childTag = parentTag.children[i]; i += 1) { |
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if (childTag.tagName === "SOURCE") { |
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var attributeValue = getData(childTag, dataAttrName); |
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if (attributeValue) { |
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childTag.setAttribute(attrName, attributeValue); |
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} |
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} |
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} |
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}; |
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var setAttributeIfNotNullOrEmpty = function setAttributeIfNotNullOrEmpty(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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var setSources = function setSources(element, settings) { |
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var sizesDataName = settings.data_sizes, |
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srcsetDataName = settings.data_srcset, |
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srcDataName = settings.data_src; |
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var srcDataValue = getData(element, srcDataName); |
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switch (element.tagName) { |
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case "IMG": |
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{ |
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var parent = element.parentNode; |
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if (parent && parent.tagName === "PICTURE") { |
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setSourcesInChildren(parent, "srcset", srcsetDataName); |
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} |
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var sizesDataValue = getData(element, sizesDataName); |
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setAttributeIfNotNullOrEmpty(element, "sizes", sizesDataValue); |
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var srcsetDataValue = getData(element, srcsetDataName); |
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setAttributeIfNotNullOrEmpty(element, "srcset", srcsetDataValue); |
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setAttributeIfNotNullOrEmpty(element, "src", srcDataValue); |
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break; |
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} |
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case "IFRAME": |
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setAttributeIfNotNullOrEmpty(element, "src", srcDataValue); |
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break; |
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case "VIDEO": |
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setSourcesInChildren(element, "src", srcDataName); |
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setAttributeIfNotNullOrEmpty(element, "src", srcDataValue); |
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break; |
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default: |
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if (srcDataValue) { |
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element.style.backgroundImage = 'url("' + srcDataValue + '")'; |
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} |
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} |
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}; |
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var isBot = "onscroll" in window && !/glebot/.test(navigator.userAgent); |
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var runningOnBrowser = typeof window !== "undefined"; |
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var supportsIntersectionObserver = runningOnBrowser && "IntersectionObserver" in window; |
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var supportsClassList = runningOnBrowser && "classList" in document.createElement("p"); |
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var addClass = function 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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var removeClass = function 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.replace(new RegExp("(^|\\s+)" + className + "(\\s+|$)"), " ").replace(/^\s+/, "").replace(/\s+$/, ""); |
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}; |
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var callCallback = function callCallback(callback, argument) { |
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if (callback) { |
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callback(argument); |
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} |
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}; |
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var loadString = "load"; |
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var errorString = "error"; |
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var removeListeners = function removeListeners(element, loadHandler, errorHandler) { |
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element.removeEventListener(loadString, loadHandler); |
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element.removeEventListener(errorString, errorHandler); |
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}; |
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var addOneShotListeners = function addOneShotListeners(element, settings) { |
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var onLoad = function onLoad(event) { |
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onEvent(event, true, settings); |
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removeListeners(element, onLoad, onError); |
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}; |
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var onError = function onError(event) { |
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onEvent(event, false, settings); |
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removeListeners(element, onLoad, onError); |
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}; |
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element.addEventListener(loadString, onLoad); |
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element.addEventListener(errorString, onError); |
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}; |
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var onEvent = function onEvent(event, success, settings) { |
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var element = event.target; |
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removeClass(element, settings.class_loading); |
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addClass(element, success ? settings.class_loaded : settings.class_error); // Setting loaded or error class
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callCallback(success ? settings.callback_load : settings.callback_error, element); |
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}; |
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function revealElement(element, settings, force) { |
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if (!force && getWasProcessed(element)) { |
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return; // element has already been processed and force wasn't true
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} |
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callCallback(settings.callback_enter, element); |
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if (["IMG", "IFRAME", "VIDEO"].indexOf(element.tagName) > -1) { |
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addOneShotListeners(element, settings); |
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addClass(element, settings.class_loading); |
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} |
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setSources(element, settings); |
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setWasProcessed(element); |
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callCallback(settings.callback_set, element); |
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} |
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/* entry.isIntersecting needs fallback because is null on some versions of MS Edge, and |
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entry.intersectionRatio is not enough alone because it could be 0 on some intersecting elements */ |
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var isIntersecting = function isIntersecting(element) { |
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return element.isIntersecting || element.intersectionRatio > 0; |
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}; |
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var getObserverSettings = function getObserverSettings(settings) { |
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return { |
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root: settings.container === document ? null : settings.container, |
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rootMargin: settings.threshold + "px" |
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}; |
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}; |
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var LazyLoad = function LazyLoad(customSettings, elements) { |
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this._settings = getInstanceSettings(customSettings); |
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this._setObserver(); |
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this.update(elements); |
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}; |
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LazyLoad.prototype = { |
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_setObserver: function _setObserver() { |
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var _this = this; |
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if (!supportsIntersectionObserver) { |
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return; |
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} |
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var revealIntersectingElements = function revealIntersectingElements(entries) { |
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entries.forEach(function (entry) { |
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if (isIntersecting(entry)) { |
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var element = entry.target; |
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_this.load(element); |
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_this._observer.unobserve(element); |
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} |
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}); |
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_this._elements = purgeElements(_this._elements); |
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}; |
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this._observer = new IntersectionObserver(revealIntersectingElements, getObserverSettings(this._settings)); |
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}, |
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loadAll: function loadAll() { |
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var _this2 = this; |
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this._elements.forEach(function (element) { |
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_this2.load(element); |
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}); |
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this._elements = purgeElements(this._elements); |
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}, |
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update: function update(elements) { |
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var _this3 = this; |
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var settings = this._settings; |
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var nodeSet = elements || settings.container.querySelectorAll(settings.elements_selector); |
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this._elements = purgeElements(Array.prototype.slice.call(nodeSet)); // nodeset to array for IE compatibility
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if (isBot || !this._observer) { |
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this.loadAll(); |
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return; |
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} |
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this._elements.forEach(function (element) { |
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_this3._observer.observe(element); |
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}); |
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}, |
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destroy: function destroy() { |
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var _this4 = this; |
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if (this._observer) { |
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purgeElements(this._elements).forEach(function (element) { |
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_this4._observer.unobserve(element); |
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}); |
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this._observer = null; |
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} |
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this._elements = null; |
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this._settings = null; |
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}, |
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load: function load(element, force) { |
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revealElement(element, this._settings, force); |
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} |
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}; |
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/* Automatic instances creation if required (useful for async script loading!) */ |
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var autoInitOptions = window.lazyLoadOptions; |
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if (runningOnBrowser && autoInitOptions) { |
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autoInitialize(LazyLoad, autoInitOptions); |
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} |
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return LazyLoad; |
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}); |
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