# FunctionDataSource to Search Multiple Fields of an Address Book at Runtime

This example uses a FunctionDataSource to perform string matching against multiple fields of a contacts database at runtime. Since the data for this example is loaded into local memory, queries should be quite fast to return data, but use of the custom function allows a more complex search algorithm. A custom formatter allows users to see their search term within the result set. An itemSelectEvent handler is used to update the input field with a custom value and to populate a hidden form field with the selected contact's ID for eventually submitting back to a server.

Find a contact: