title: JSF component object
body: <p>There are many tutorials on the internet where component object on JSF page is used.
  Usually component.clientId or component.valid are used.
  Example</p>
  
  <pre><code>&lt;h:inputText .... styleClass="#{component.valid ? '' : 'ui-input-invalid'}"/&gt;
  </code></pre>
  
  <p>If i create page with such component, i get an error:</p>
  
  <pre><code>javax.el.PropertyNotFoundException: 
  The class 'javax.faces.component.UIPanel' does not have the property 'valid'.
  </code></pre>
  
  <p>I googled that for inputText should be there UIInput class (which has isValid method), but i have there UIPanel (which dasn't).</p>
  
  <p>Any idea why is there UI Panel?
  (Java EE 6, JSF 2.1, Weblogic 12.1.2)</p>