<p id="app" ng-app="app" ng-controller="ctrl">
    <a ng-if="show" onclick="func1()">click</a>
</p>
<script src="http://cdn.bootcss.com/angular.js/1.5.6/angular.min.js"></script>
<script>
    angular.module('app', []).controller('ctrl', function ($scope, $timeout) {

        $timeout(function () {
            $scope.show = true
        })

        $scope.func1 = function () {
            alert(arguments[0])
        }
    })

    function func1() {
        angular.element(document.getElementById('app')).scope().func1('123')
    }
</script>