title: button style when form is not valid
body: <p>i'm using jsf/primefaces, when a component of my form is not valid, it is surrounding with red border (his style is ui-state-error).
  Some of component doesn't have ui-state-error behaviour by default so i'm using </p>
  
  <pre><code>&lt;p:selectOneMenu styleClass="#{component.valid ? '' : 'ui-state-error'}"&gt;
  </code></pre>
  
  <p>I'm trying to have a button with red border but "component.valid" doesn't work for p:commandButton. Do you have an idea please ?
  Thanks</p>