After examining the ClickServlet class, I noticed the newPageInstance() method,
which is where new instances of Page objects are created. By default,
newPageInstance() calls Class.newInstance() on the given class. This can be
overridden by subclassing ClickServlet. However, I believe this functionality
should be factored out into a separate class. A separate page factory would
allow page objects to be created in more flexible ways (e.g., from Spring
contexts or Tapestry IoC registries) without altering the ClickServlet. I
imagine an interface like the following:
interface PageFactoryService {
void onInit(ServletContext servletContext) throws Exception;
Page newPageInstance(String path, Class<? extends Page> pageClass,
HttpServletRequest request) throws Exception;
void onDestroy();
}
The ConfigService API would be revised to support this new service:
interface ConfigService {
...
PageFactoryService getPageFactoryService();
...
}
This interface would have a default implementation, which could be overidden
with the help of ConfigService. ClickServlet.newInstance() could then delegate
to this page factory.
