A UISelectOne component allows the user to select one value from a set of values. This component can be rendered as a list box, a set of radio buttons, or a menu. This section explains the selectOneMenu tag. The selectOneRadio and selectOneListbox tags are written in a similar way. The selectOneListbox tag is similar to the selectOneMenu tag except that selectOneListbox defines a size attribute that determines how many of the items are displayed at once.
The selectOneMenu tag represents a component that contains a list of items, from which a user can choose one item. The menu is also commonly known as a drop-down list or a combo box. The following code snippet shows the selectOneMenu tag from the bookcashier.jsp page of the Duke’s Bookstore application. This tag allows the user to select a shipping method:
<h:selectOneMenu id="shippingOption" required="true" value="#{cashier.shippingOption}"> <f:selectItem itemValue="2" itemLabel="#{bundle.QuickShip}"/> <f:selectItem itemValue="5" itemLabel="#{bundle.NormalShip}"/> <f:selectItem itemValue="7" itemLabel="#{bundle.SaverShip}"/> </h:selectOneMenu>
The value attribute of the selectOneMenu tag maps to the property that holds the currently selected item’s value. You are not required to provide a value for the currently selected item. If you don’t provide a value, the first item in the list is selected by default.
Like the selectOneRadio tag, the selectOneMenu tag must contain either a selectItems tag or a set of selectItem tags for representing the items in the list. The UISelectItem, UISelectItems, and UISelectItemGroup Components explains these tags.