I have a directive like the one of the examples from AngularJS, shown below. How can I call the toggle method from the global scope? I want to be able to toggle the zippy from some legacy code.

myApp.directive('zippy', 
function(){
    return {
        restrict: 'E',
        replace: true,
        transclude: true,
        scope: { title:'bind' },
        template:
        '<div class="zippy">' +
        '<div class="title">{{title}}</div>' +
        '<div class="body" ng-transclude></div>' +
        '</div>',
        link: function(scope, element, attrs) {
            var title = angular.element(element.children()[0]),
            opened = true;
            title.bind('click', toggle);
            function toggle() {
                opened = !opened;
                element.removeClass(opened ? 'closed' : 'opened');
                element.addClass(opened ? 'opened' : 'closed');
            }
            toggle();
        }
    }
});