Data-driven apps

In this chapter, we are going to go through the steps of building a simple mobile app with an embedded database for managing a list of todo items. Before jumping into coding, let’s first look into the overall application architecture. The more complex the system we want to build, the more important it is to properly structure it.

The typical approach is to divide and conquer; break a big problem into smaller problems that are simpler to solve. The most common approach in software development is to break the whole system into clearly separated tiers. In a data-driven app, we should be able to identify at least two logical parts: the UI and data access logic. Clear separation of these two tiers enables a plugin architecture, where the UI can connect to different data access blocks in a standard way and the UI can be replaced without touching the underlying data access layer.

In the context of a Delphi app, we can split our project into three independent...