how to create a new instance of the object for ng-repeat

Question

How can i create a new instance of an object with different(unique) hashkey or id for ng-repeat?. I tried to use "track by", but can't get it to work.

My code below:

For each row in the table (could be 5 ,10 ...rows), I want to display the same set of check boxes stored in this list:

    $scope.list_of_checkboxes = 
[
    {
      name: "ch1",
      properties:[{t:"text1",v:0},{t:"text2",v:0},{t:"text3",v:0}]
    },
     {
      name: "ch2",
      properties:[{t:"text1",v:0},{t:"text2",v:0},{t:"text3",v:0}]
    }
 ];

Once check box is checked i am storing check box object in $scope.table_rows.objects by using this library: http://vitalets.github.io/checklist-model/

$scope.table_rows=[{row_1:'row # 1', objects:[]},{row_2: 'row # 2',objects:[]},{row3:'row # 3',objects:[]}]

Check boxes are displayed and functioning fine. However, when i store objects of checked check boxes in $scope.table_rows.objects, they all have the same hashkey. This is the problem. Because, when i display properties:[{t:"text1",v:0},{t:"text2",v:0},{t:"text3",v:0}] as input fields and update one of the properties values for example table_rows[key].objects[1].v = 30, the same value getting copied to properties of the same object stored in other rows.

I tried to return new instance (but it doesn't work):

$scope.list_of_checkboxes = function (){ 

 return ([
    {
      name: "ch1",
      properties:[{t:"text1",v:0},{t:"text2",v:0},{t:"text3",v:0}]
    },
     {
      name: "ch2",
      properties:[{t:"text1",v:0},{t:"text2",v:0},{t:"text3",v:0}]
    }
 ])
}

Answer 1

Not the complete implementation but you can try using track by $id(obj) :

HTML :

<div ng-app="myApp" ng-controller="Ctrl">
<table>
    <tr ng-repeat=" row in rows track by row.name">
<td ng-repeat="role in roles track by $id(role)" >
  <input type="checkbox" checklist-model="user.roles" checklist-value="$id"/> {{role.name}},{{$id}}
        </td>
        </tr>
</table>
<br><br><br>
user.roles {{ user.roles | json }}
</div>

JavaScript :

var app = angular.module("myApp", ["checklist-model"]);

app.controller('Ctrl', function($scope) {
$scope.rows=[{
    name:'first'
},{
    name:'second'
},{
    name:'third'
}];
$scope.roles =[
{
  name: "ch1"
},
 {
  name: "ch2"    }
];

$scope.user = {
roles: []
};
});

Demo : http://jsfiddle.net/FC9c7/78/