Modify one field in a MVVM DataSource

[Dr.YSG]

I have a DataSource that I am using as the VM for a Grid.

After the reader grabs the data, I have a change event that I need to run to compare what is local (in an indexed db) with what was fetched.

In the snippet below I set row[i].Newer to false if the data is not newer.
Then I trigger the change on the ObservableObject.

This is all working fine, until I do a "cancel changes" from the Grid Toolbar. which seems to reset things.

How should I be updating the DS?

if (vm.oldTest(layers.at(i).Type, layers.at(i).Date, dbm.LayerInfo)) {
    layers.at(i).Newer = false;
    layers.at(i).trigger("change");
}

[Petur Subev]

Hello,

The dataSource of the Grid keeps copy of the 'original' dataItems (it saves it when the Grid is bound) and when the cancelChangs is invoked - all the items from that pristine collection are used and all other changes applied are lost.

If sync of the dataSource is called - on success the pristine collection is updated with these successfully updated dataItems.

Kind Regards,
Petur Subev
Telerik