ractive/src/utils/matches.js

Next-generation DOM manipulation

import isClient from 'config/isClient';
import vendors from 'config/vendors';
import createElement from 'utils/createElement';

var matches, div, methodNames, unprefixed, prefixed, i, j, makeFunction;

if ( !isClient ) {
	matches = null;
} else {
	div = createElement( 'div' );
	methodNames = [ 'matches', 'matchesSelector' ];

	makeFunction = function ( methodName ) {
		return function ( node, selector ) {
			return node[ methodName ]( selector );
		};
	};

	i = methodNames.length;

	while ( i-- && !matches ) {
		unprefixed = methodNames[i];

		if ( div[ unprefixed ] ) {
			matches = makeFunction( unprefixed );
		} else {
			j = vendors.length;
			while ( j-- ) {
				prefixed = vendors[i] + unprefixed.substr( 0, 1 ).toUpperCase() + unprefixed.substring( 1 );

				if ( div[ prefixed ] ) {
					matches = makeFunction( prefixed );
					break;
				}
			}
		}
	}

	// IE8...
	if ( !matches ) {
		matches = function ( node, selector ) {
			var nodes, parentNode, i;

			parentNode = node.parentNode;

			if ( !parentNode ) {
				// empty dummy <div>
				div.innerHTML = '';

				parentNode = div;
				node = node.cloneNode();

				div.appendChild( node );
			}

			nodes = parentNode.querySelectorAll( selector );

			i = nodes.length;
			while ( i-- ) {
				if ( nodes[i] === node ) {
					return true;
				}
			}

			return false;
		};
	}
}

export default matches;