JSF2 Flash Scope
-----------------


- Different from other scopes since we don't use annotations

- Really, there's just a Flash-scope OBJECT maintained by JSF
  that contains methods like a Map. 

- Concept borrowed from Ruby on Rails

- The key point is that unlike request-scoped beans, flash scoped
  beans survive a single redirection navigation. Request-scoped
  beans only survive a forward. So flash scope helps us implement
  the Post/Redirect/Get pattern efficiently

- Here's some code:

 public class MyBean
 {
     public String method1()	// "action" method
     {
        . . .
	Flash flash = FacesContext.getCurrentInstance().getExternalContext().getFlash();

        flash.put("whatever", someObject);

        return "page2?faces-redirect=true";  // force redirection
     }
}

- Then in the redirected JSF page, you can use the EL:

      <h:outputText value="#{flash.whatever.someProp}" />