One more question on this subject ... how would I know what/when to add to the "requires" section?
There's nothing about modifying that section in the walkthrough for the CityBars sample application ... if it wasn't for doing a line-by-line comparison to the existing working demo download, I never would have realised I needed those entries.
I had assumed that by adding the components to the designer surface, the necessary "requires" would be automagically populated. Not the case?
Requires are simple but seemingly hard to explain.
A few examples:
If a store uses a particular model then it would need to require that model to be loaded before it's defined.
If you have a view that instantiates another view by name or xtype then you'd need to require it.
In general, the framework should do a good job telling you that files we're loaded in the correct order if you do it wrong.
Application requires are slightly different in that it says here's all my stuff. It's up to you if you want to require only top level classes and have them require what they need or simply require everything.