A SingleSelect widget is a list control that allows a user to select one item from a list of items. In the default state the SingleSelect control has a read-only text area with a dropdown button. When the dropdown button is clicked, a dropdown window appears containing a vertical list of items from which the user can select just one item. On selection, the dropdown disappears and the option selected by the user is set in the widget’s text area. The actual value of the SingleSelect is the key value of the selected item and this is the value that is transfered to the server.

The list of items presented in the SingleSelect dropdown window is obtained from the ListCommand component that is associated with the widget.

This component binds to a Java non-array data type object.

Listing 1: SingleSelect UPL

!ui-select:frmCar
    caption:$s{Favorite Car} binding:code
    list:$s{carlist} blankOption:$s{}

Listing 2: Car Listable class

public class Car implements Listable {

    private String code;

    private String name;
    
    public Car(String code, String name) {
        this.code = code;
        this.name = name;
    }

    @Override
    public String getListKey() {
        return code;
    }

    @Override
    public String getListDescription() {
        return name;
    }

    ...
}

Listing 3: Car list command

@Component("carlist")
public class CarListCommand extends AbstractListCommand {

    @Override
    public List<? extends Listable> execute(Locale locale, Object... params)
            throws UnifyException {
        List<Car> list = new ArrayList<CarData>();
        list.add(new Car("HND", "Honda"));
        list.add(new Car("LEX", "Lexus"));
        list.add(new Car("MRC", "Mercedes-Benz"));
        list.add(new Car("TYA", "Toyota"));
        return list;
    }
}