Java Reference
In-Depth Information
The values displayed in the confirmation page are taken from our managed bean,
confirming that the bean's properties were populated correctly.
JSF Validation
Earlier in this chapter we discussed how the
required
attribute for JSF input fields
allows us to easily make input fields mandatory.
If a user attempts to submit a form with one or more required fields missing, an error
message is automatically generated.
The error message is generated by the
<h:message>
tag corresponding to the invalid
field. The string
First Name
in the error message corresponds to the value of the
label
attribute for the field. Had we omitted the label attribute, the value of the
ields
id
attribute would have been shown instead. As we can see, the
required
attribute makes it very easy to implement mandatory field functionality in
our application.
Recall that the
age
field is bound to a property of type
Integer
in our managed
bean. If a user enters a value that is not a valid integer into this field, a validation
error is automatically generated.
