The goal we're working towards is for the Notes home page to automatically update the list of notes, as notes are edited or deleted. What we've done so far is to restructure the application startup so that Socket.IO is initialized in the Notes application. There's no change of behavior yet, except that it will crash due to a missing function.
The approach is for the Notes model classes to send messages whenever a note is created, updated, or deleted. In the router classes, we'll listen to those messages, then send a list of note titles to all browsers attached to the Notes application.
Where the Notes model so far has been a passive repository of documents, it now needs to emit events to any interested parties. This is the listener pattern and, in theory, there will be code that is interested in knowing when notes are created, edited, or destroyed. At the moment, we'll use that knowledge to update the Notes home page, but there are many potential other...