JS implementation of [DOMElement].dataset property

gistfile1.js

/**
* Not all browsers support the .dataset property
* for DOM elements. This function performs the same
* function: it gathers all the data-* attributes of a
* DOM element, and returns them as a hash.
* Example: <p id="testP" data-monkey="fez" data-turtle="mine"></p>
* getDataset(p); // {'monkey':'fez', 'turtle':'mine'}
*/
function getDataset(el) {
	var dataset = {};
	var attributes, attribute, attributeName, i;

	if (el && el.nodeType==1 /* DOMElement */) {
		attributes = el.attributes;
		if (attributes && attributes.length) {
			i = attributes.length;
			while (i--) {
				attribute = attributes.item(i);
				attributeName = attribute.nodeName;
				if (attributeName.slice(0,5) === 'data-') {
					dataset[attributeName.slice(5)] = attribute.value;
				}
			}
		}
	}
	return dataset;
}