In general, widget support such behavior - request data only on popup open or typing. This, however, changes when MVVM value binding is used, because it sets the model value via widget value
method, which on the other hand will trigger Ajax request if the widget is empty. In order to overcome this behavior, you will need to use a custom
MVVM value binding, which will implement this deferred value setting and data binding. I would suggest you check this code library
, which shows exactly how to accomplish this task (ComboBox is an editor template in the Grid).
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