问Angular指令如何给元素添加属性？

EN

//html
<div ng-app="app">
    <div ng-controller="AppCtrl">
        <a my-dir ng-repeat="user in users">{{user.name}}</a>
    </div>
</div>

//js
var app = angular.module('app', []);
app.controller("AppCtrl", function ($scope) {
    $scope.users = [{name:'John',id:1},{name:'anonymous'}];
    $scope.fxn = function() {
        alert('It works');
    };

})  
app.directive("myDir", function ($compile) {
    return {
        link:function(scope,el){
            el.attr('ng-click','fxn()');
            //$compile(el)(scope); with this the script go mad 
        }
     };
});