Trigger JSF validation using ajax after focus lost

Question

How do you trigger validation on an input component when the component loses focus using ajax instead of waiting for the form to be manually submitted?

Answer 1

Put a <f:ajax event="blur"> in the UIInput component which re-renders a <h:message> associated with the component in question.

<h:inputText id="foo" value="#{bean.foo}" required="true">
    <f:ajax event="blur" render="fooMessage" />
</h:inputText>
<h:message id="fooMessage" />

See also JSF 2.0 tutorial with Eclipse and Tomcat - the view and finetuning validation