In order to make the Portlet adapter as efficient as possible, a caching strategy was implemented that is beyond the scope of the Portlet's control. It works as follows: uPortal will cache the contents of a Portlet screen until one of the following occurs:
- The user clicks on a link or button within the Portlet.
- The user clicks on a button within the Portlet control bar, i.e. Edit, Help, About, etc.
- The Portlet is focused or unfocused, i.e. the Portlet alternates between being the root of the layout and not the root of the layout.
- A PortalEvent is sent to the Portlet.
When one of these activities occurs, it usually triggers a state change within the Portlet, and the new screen is cached until one of these activities happens again. Therefore, simply clicking refresh on your browser will not cause the Portlet to render itself again. The optional Portlet caching settings mentioned in the Portlet Specification are not implemented at this time.