By default the Kendo UI DataSource filters data on the client. For the DropDownList widget, filtration is turned off by default - to enable it, simply specify the filtering method ("startswith", "contains" or "endswith") in the DropDownList filter option
"' Choose a Product... '"
Checkout the following Dojo example
, where the above is demonstrated in action.
In case you would like to perform filtering on the serverSide, the DataSource's serverFiltering option
has to be set to true. This will force filtering to be performed on the server side.