So far the Toast Back End has been largely headless—content is written to the console, but there is no user interaction. In this chapter we add a web-based user interface to Toast. The goal here is not to create a fancy UI but rather to talk about some commonly used extensibility mechanisms and metaphors set in the context of providing a UI for Toast.
We use this context to introduce the Whiteboard Pattern, a powerful style of using OSGi services to aggregate operations. In building the portal we also look at how to insulate our domain code from OSGi in cases where explicit OSGi use is inevitable.
In this chapter we do the following
• Introduce and explore the Whiteboard Pattern
• Build on our current back end infrastructure ...