a directive to give focus to an element, adds tabindex if the element doesn't already have it

focus-directive.js

(function() {
    var app = angular.module('mcbFocus', [])
        .directive('focusOn', function() {
            return function(scope, elem, attr) {
            	if(attr.tabIndex === undefined){
            		elem.attr('tabindex', -1);
		}
                scope.$on('focusOn', function(e, name) {
                    if (name === attr.focusOn) {
                        elem[0].focus();
                    }
                });
            };
        })
        .factory('focus', function($rootScope, $timeout) {
            return function(name) {
                $timeout(function() {
                    $rootScope.$broadcast('focusOn', name);
                });
            }
        });
})();