title: How to parameterize requiredMessage attribute in composite component?
body: <p>BalusC provided a good answer to a question about how to set messages per composite component. <a href="https://stackoverflow.com/questions/9247124/specifying-different-error-messages-for-different-composite-components/9248743#comment11658784_9248743">Specifying different error messages for different composite components</a>
  The answer involved using per component resource bundles.</p>
  
  <p>Ive applied this approach but when I use <code>{0}</code> in the message to specify the current component label as part of the message, the <code>{0}</code> is rendered as is in my error, rather than being resolved. Is this resolution of labels available when I use this approach? Or do I have to manually build up the error message in the composite component? e.g.</p>
  
  <pre><code>requiredMessage="#{cc.resourceBundleMap.requiredMessage} #{cc.attrs.prefix} #{cc.attrs.label}"
  </code></pre>
  
  <p>I guess the deeper question is how can I have parameterised message strings in my resource bundle? Will I need to build some kind of custom message resolver?</p>