Angular: Empty Fiddle

http://angularjs.org/

HTML

<script src="http://code.angularjs.org/angular-1.0.1.js"></script>
<div ng-controller="TestCtrl">
    
    <button data-id="345" ng-click="doStuff($event.target)">Button</button>
    
</div>

JavaScript

var app = angular.module("app", []);

app.controller("TestCtrl", function ($scope) {

    $scope.doStuff = function (item) {
        console.log(item); // OK
        console.log(angular.element(item)[0]); // OK
        console.log(angular.element(item)[0].data('id')); // undefined
    };

});