directive.js

focusApp.directive('activeLink', function($location) {

    var link = function(scope, element, attrs) {
        scope.$watch(function() { return $location.path(); }, 
        function(path) {
            var url = element.find('a').attr('href');
            if (url) {
                url = url.substring(1);
            }

            if (path == url) {
                element.addClass("active");
            } else {
                element.removeClass('active');
            }

        });
    };

    return {
        restrict: 'A',
        link: link
    };
});