Lean Mobile App Development

Data layer

Switching from one service provider to another (key partner) is easy if your app is well structured. Use a separate layer for accessing data and define contracts for the communication between your data layers and your controllers. Contracts are known as an interface (for Android) or as a protocol (for iOS). They contain no implementation and are nothing but appointments between one class and another. They define what methods are available, what parameters are required, and what the result type will be.

For example, let's say we are getting data from some kind of source. In the interface IRepository, we will define the names, results, and parameters for all methods that represent some operation. To be more precise, let's say we ...