public class Pageflow implements Serializable {
...
public static Pageflow instance()
{
...
return (Pageflow) Component.getInstance(Pageflow.class, ScopeType.CONVERSATION, true);
}
...
public class Component {
...
public static Object getInstance(String name, ScopeType scope, boolean create)
{
Object result = scope.getContext().get(name);
result = getInstance(name, create, result);
return result;
}
...
public class ServerConversationContext implements Context {
...
public Object get(String name) {
...
LinkedList<String> stack = getIdStack();
...
for ( String id: stack )
{
result = session.getAttribute( getKey(name, id) );
if (result!=null) return result;
}
return null;
...
}
Using this pattern we can have only one such
Component (in this case
Pageflow) per
Conversation stack. When we ask for a new
instance we will get an old one from some parent
Conversation.
This is the main thing that prevents using nested
Pageflows.
May be it is reasonable to add another option in
Component.getInstance() to lookup only in one current
Conversation.
