It was a lengthy chapter, but we did a lot here. We learned how to efficiently use extract method refactoring to simplify and clarify the code. This refactoring was applied to our code to greatly simplify the existing data retrieval flow.
We also saw how we can use the Factory Methods to create reusable Observables by wrapping their complex creation code inside familiarly named methods.
As we were exploring various ways of the method extraction helping us make the code easier to maintain, we saw the limits of this approach, and we learned to use ObservableTransformer to help us overcome those limitations.
The ObservableTransformer was successfully applied to simplify the persistence and error notification code. Further, we learned ...