Angularjs的ng-repeat中去除重复数据的方法

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>