AndularJS - Pass Event into custom directive

Pass Event into custom directive

//controller
angular.module('b1').controller('WarehousePurchaseEdit',
    function () {
    c.onPurchaseDateChange = function () {
        alert(c.oldPurchaseDate);
    }

)};

//view
<div ext-on-changes purchase="c.model" handler="c.onPurchaseDateChange()"></div>

//directive
angular.module('b1').directive("extOnChanges", function ($translate) {
    return {
        scope: {
            purchase: '=',
            handler: '&'
        },
        template: 'Current date: {{purchase.purchaseDate}}, current warehouse: {{purchase.warehouseName}}' +
            '<button ng-click="s.clickFromDirective()">Call Controller function</button>    ',
        controllerAs: 's',
        controller: function ($scope) {
            var s = this;
            s.clickFromDirective = function (){
                // var params = {event: event, el: element};
                $scope.handler();
            }
        }
    }
});