The Java EE 5 Tutorial (PDF) - Oracle Software Downloads

Referencing a Backing Bean Method
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“Writing a Method to Handle an Action Event” on page 404 describes how to implement a
method that handles an action event.
Referencing a MethodThat PerformsValidation
If the input of one of the components on your page is validated by a backing bean method, you
refer to the method from the component’s tag using the validator attribute.
The Coffee Break application includes a method that performs validation of the email input
component on the checkoutForm.jsp page. Here is the tag corresponding to this component:
This tag references the validate method described in “Writing a Method to Perform
Validation” on page 404 using a method expression.
Referencing a MethodThat Handles aValue-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:
For illustration, “Writing a Method to Handle a Value-Change Event” on page 405 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: