Styling input component after validation failed

Question

How can I style a component after validation failed?

I have the following textfield:

Answer 1

I tried the linked example and got the SystemEventListener.processEvent() to trigger when using

So i figured it has do with faces-config.xml. Specifying the primefaces InputText as source-class did the trick:

    
        RequiredFieldValidationListener
        javax.faces.event.PostValidateEvent
        org.primefaces.component.inputtext.InputText
    

to use