30.1 Hierarchical Data and Disclosures

In keeping with the automotive theme adopted in the previous chapter, consider an app required to present the user with the hierarchical data illustrated in Figure 30-1:

Figure 30-1

When designing such an app, one option would be to begin with a List containing only the two categories of car (Hybrid and Electric), presenting each subsequent layer of data on separate screens. A typical path through such a user interface might involve selecting the Hybrid category to navigate to a list containing the two hybrid car manufacturers, within which selecting Toyota would display a third screen containing the two hybrid models together with a selectable entry to display the hybrid models manufactured by Toyota’s Lexus sub-brand. Having viewed the Lexus hybrid models, the user would then need to navigate back through multiple list levels to be able to navigate to view Tesla electric vehicles.

Clearly a better option would be to display...