Jquery toggleAttr plugin, which toggles the (boolean) attribute for each element or, if given a second parameter toggles the attribute of each element to that value, like toggle(bool) and toggleClass(class, bool) do.

jquery.toggleattr.coffee

$.fn.toggleAttr = (attr, bool) ->
	if bool
		return @attr attr, attr
	if typeof bool isnt 'undefined'
		return @removeAttr attr
	@each ->
		$e = $ @
		if typeof $e.attr(attr) is 'undefined'
			$e.attr attr, attr
		else
			$e.removeAttr attr

jquery.toggleattr.js

$.fn.toggleAttr = function(attr, bool) {
	if (bool) {
		return this.attr(attr, attr);
	}
	if (typeof bool !== 'undefined') {
		return this.removeAttr(attr);
	}
	return this.each(function() {
		var $e = $(this);
		if (typeof $e.attr(attr) === 'undefined') {
			$e.attr(attr, attr);
		} else {
			$e.removeAttr(attr);
		}
	});
};