75 lines
1.8 KiB
JavaScript
75 lines
1.8 KiB
JavaScript
/*
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@preserve dataset polyfill for IE < 11. See https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/dataset and http://caniuse.com/#search=dataset
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@author ShirtlessKirk copyright 2015
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@license WTFPL (http://www.wtfpl.net/txt/copying)
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*/
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const dash = /-([a-z])/gi;
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const dataRegEx = /^data-(.+)/;
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const hasEventListener = !!document.addEventListener;
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const test = document.createElement('_');
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const DOMAttrModified = 'DOMAttrModified';
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let mutationSupport = false;
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function clearDataset(event) {
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delete event.target._datasetCache;
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}
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function toCamelCase(string) {
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return string.replace(dash, function (_, letter) {
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return letter.toUpperCase();
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});
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}
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function getDataset() {
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const dataset = {};
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for (let attribute of this.attributes) {
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let match = attribute.name.match(dataRegEx);
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if (match) {
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dataset[toCamelCase(match[1])] = attribute.value;
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}
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}
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return dataset;
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}
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function mutation() {
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if (hasEventListener) {
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test.removeEventListener(DOMAttrModified, mutation, false);
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} else {
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test.detachEvent(`on${DOMAttrModified}`, mutation);
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}
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mutationSupport = true;
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}
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if (!test.dataset) {
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if (hasEventListener) {
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test.addEventListener(DOMAttrModified, mutation, false);
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} else {
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test.attachEvent(`on${DOMAttrModified}`, mutation);
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}
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// trigger event (if supported)
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test.setAttribute('foo', 'bar');
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Object.defineProperty(Element.prototype, 'dataset', {
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get: mutationSupport
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? function get() {
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if (!this._datasetCache) {
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this._datasetCache = getDataset.call(this);
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}
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return this._datasetCache;
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}
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: getDataset
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});
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if (mutationSupport && hasEventListener) {
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// < IE9 supports neither
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document.addEventListener(DOMAttrModified, clearDataset, false);
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}
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}
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