Angularjs的ng-repeat中去除重复的数据

ngApp.filter('unique', function () {
return function (collection, keyname) {
var output = [],
keys = [];

angular.forEach(collection, function (item) {
var key = item[keyname];
if (keys.indexOf(key) === -1) {
keys.push(key);
output.push(item);
}
});

return output;
};
});

<div ng-repeat="item in items | unique: 'id'"></div>