KendoUI Treeview with AngularJS uncheck checkboxes - angularjs

Question

I'm using KendoUI (v2015.1.318) with AngularJS (v1.3.14). After every click on a node, the data will be fetched from an API.
After selecting some items and clicking on the button "add", the items will be added in a seperated list, the expanded treenodes must stay visible but all the
checked items must be unchecked.
After I iterated through the datasource to uncheck the checked items , I have call SetDataSource again. When I have expanded a lot of nodes and checked a few, the UI freezes some seconds while it's processing.
I was wondering if there wasn't a more efficient way to execute this.
I made an example without API call:
$scope.saveTreeFields = function () {
var data = $scope.tree.dataSource._data;
for (var i = 0, j = data.length; i < j; i++) {
checkChildren(data[i]);
}
function checkChildren(data) {
if (data.checked) {
data.checked = false;
}
if (data.items !== undefined) {
for (var i = 0, j = data.items.length; i < j; i++) {
checkChildren(data.items[i]);
}
}
}
$scope.tree.setDataSource(data)
};
Plunker example

Answer 1

Received an answer from Telerik itself.
you can call the dataItem set("checked", false) method to notify the
model of the field change, and the TreeView will update automatically.
Code changes
$scope.saveTreeFields = function () {
var data = $scope.tree.dataSource.data();
for (var i = 0, j = data.length; i < j; i++) {
checkChildren(data[i]);
}
function checkChildren(data) {
if (data.checked) {
data.set("checked", false);
}
if (data.items !== undefined) {
for (var i = 0, j = data.items.length; i < j; i++) {
checkChildren(data.items[i]);
}
}
}
};