package org.andromda.cartridges.jsf.renderkit;
   
   import java.io.IOException;
   import java.util.UUID;
   import javax.faces.component.UIComponent;
   import javax.faces.context.FacesContext;
   import javax.faces.render.Renderer;
   import org.andromda.cartridges.jsf.component.TransactionToken;
   
  /**
   * The transaction token renderer (just adds the transaction token value
   * as an attribute of the parent component so we can skip multi-submits of the same action).
   *
   * @author Chad Brandon
   */
  public class TransactionTokenRenderer
      extends Renderer
  {
      /**
       * @see javax.faces.render.Renderer#encodeBegin(javax.faces.context.FacesContext, javax.faces.component.UIComponent)
       */
      @SuppressWarnings("unchecked")
      public void encodeBegin(
          FacesContext context,
          UIComponent component)
          throws IOException
      {
          if (component.getParent() != null)
          {
              component.getParent().getAttributes().put(TransactionToken.TRANSACTION_TOKEN, UUID.randomUUID().toString());
          }
      }
  }