Referencing a Method That Handles a Value-change Event

If you want a component on your page to generate a value-change event and you want that event to be handled by a backing bean method, you refer to the method using the component’s valueChangeListener attribute.

The name component on the bookcashier.jsp page of the Duke’s Bookstore application references a ValueChangeListener implementation that handles the event of a user entering a name in the name input field:

<h:inputText
     id="name"
     size="50"
     value="#{cashier.name}"
     required="true">
    <f:valueChangeListener type="listeners.NameChanged" />
</h:inputText>

For illustration, Writing a Method to Handle a Value-Change Event describes how to implement this listener with a backing bean method instead of a listener implementation class. To refer to this backing bean method, the tag uses the valueChangeListener attribute:

<h:inputText
     id="name"
     size="50"
     value="#{cashier.name}"
     required="true"
    valueChangeListener="#{cashier.processValueChange}" />
</h:inputText>

The valueChangeListener attribute of this component tag references the processValueChange method of CashierBean using a method expression. The processValueChange method handles the event of a user entering his name in the input field rendered by this component.

Writing a Method to Handle a Value-Change Event describes how to implement a method that handles a ValueChangeEvent.