Jquery extensions that add missing addClass, removeClass, and hasClass shims for SVG elements

addClass, removeClass, and hasClass shims

	//addClass shim for SVG
	var originalAddClass = $.fn.addClass;
	$.fn.addClass = function(value) {
		var orig = originalAddClass.apply(this, arguments);

		if(!value) return orig;

		for (var i=0; i<this.length; i++ ) {
			var elem = this[ i ];
			if ( elem instanceof SVGElement ) {
				var newClasses = value.split(' ');
				var classes = $(elem).attr('class') || '';

				for (var j=0; j<newClasses.length; j++) {
					if(!$(elem).hasClass(value)) {
						//classname doesn't already exist
						classes += ' ' + newClasses[j];
					}
				};
				classes = classes.trim();
				if (classes != '') {
					$(elem).attr('class', classes);
				}
			}
		}
		return orig;
	};

	//removeClass shim for SVG
	var originalRemoveClass = $.fn.removeClass;
	$.fn.removeClass = function(value) {
		var orig = originalRemoveClass.apply(this, arguments);

		for (var i=0; i<this.length; i++ ) {
			var elem = this[ i ];
			if ( elem instanceof SVGElement ) {
				if ( $(elem).attr('class') ) {
					var classes = $(elem).attr('class').split(' ');
					var classesToRemove = value.split(' ');

					for (var j=0; j<classesToRemove.length; j++) {
						var index = classes.indexOf(classesToRemove[j]);
						if (index > -1) {
							//remove the class from the array
							classes.splice(index, 1);
						}
					};
					classes = classes.join(' ');

					if(classes=='') {
						//if there are no more classnames remaining, remove the attribute altogether
						$(elem).removeAttr('class');
					}
					else {
						//otherwise, update the classname
						$(elem).attr('class', classes);
					}
				}
			}
		}
		return orig;
	};

	//hasClass shim for SVG
	var originalHasClass = $.fn.hasClass;
	$.fn.hasClass = function(value) {
		var orig = originalHasClass.apply(this, arguments);

		for (var i=0; i<this.length; i++ ) {
			var elem = this[ i ];
			if ( elem instanceof SVGElement ) {
				if ( $(elem).attr('class') ) {
					var currentClasses = $(elem).attr('class').split(' ');

					var index = currentClasses.indexOf(value);
						if(index > -1) {
							return true;
						}
						else {
							return false;
						}
				}
				else {
					return false;
				}
			}
		}
		return orig;
	};