Passing data from page to page: clarification requested

Question

Hello,
I found an old post by craig.mcc which suggests:
"When using JavaServer Faces, your best design strategy is to pretend that there is no such thing as a URL -- that should be an invisible implementation detail, which merely adds complexity if you expose it. Instead, if you need to pass information from one page to another, you should store it as a request/session/application scope attribute (as appropriate) where the destination resource (the "LogIn.jsf" page in this case) can retrieve it via a value binding expression."
Can anyone clarify "store it as a request/session/application scope attribute"? I'm just not entirely sure what he's referring to, or how it might look.
Thanks,
Ryan

Answer 1

Ryan, here is what I did:
(To use your example)
<h:form>
<h:command_link action="submit"
     actionListener="#{MyBean.commandListener}">
<f:parameter name="param1" value="value1" />
<f:parameter name="param2" value="value2" />
</h:command_link>
</h:form >
The Backing Bean Method would look like:
public void commandListener( ActionEvent evt ) {
String param1, param2;
UICommand command = (UICommand)evt.getComponent();
List commandChildren = command.getChildren();
for ( Iterator it = commandChildren.iterator(); it.hasNext(); ) {
UIComponent child = (UIComponent) it.next();
if ( child instanceof UIParameter ) {
String parmName = (String) ( (UIParameter)child ).getName();
String parmValue = (String) ( (UIParameter)child ).getValue();
if ( parmName.equals("param1") )
_param1 = parmValue;
else if ( parmName.equals("param2") )
_param2 = parmValue;
} // end-of-for-loop     
// Other processing on param1 and param2 ........
And you would have a Navigation-rule that maps the action outcome of "submit" to "test.jsp".