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>