The PAF renders gears serially (one after the other) so you need to keep that in mind when designing your message passing. A gear rendered earlier in the page cannot see messages posted from a gear later in the page until the page is refreshed. Some ways you can share data among gears are the following:
Bundle the related gears into a single Web application and use the session or application J2EE context.
Use request attributes. The limitation of this is that the classloader policies of the J2EE specifications can only guarantee primitive object types (Strings, Integers, etc.)
Use a back-end persistence layer, such as EJBs or Repositories.
Use a container-specific mechanism. In the case of ATG, this would mean adding an object (for example, a globally or session-scoped component) and accessing it through JNDI.
Use Java Messaging System (JMS) messaging.
