Screen Navigation in iOS

Bohdan Orlov tackles one of iOS development's messiest problems: screen navigation that's actually testable and maintainable. Most apps get this wrong from day one.

This deep dive walks through iOS navigation patterns from basic UIViewController presentations to sophisticated coordinator architectures. Orlov progressively adds abstraction layers to decouple screens and make navigation logic unit testable, addressing real-world challenges like deep links and push notifications.

Key Takeaways

• Storyboard segues force runtime string identifiers and two-step initialization patterns
• Protocol-oriented dependency injection decouples view controllers and enables unit testing
• Flow Coordinators create module facades but require parallel UI hierarchy maintenance
• Deep link navigation uses graph algorithms to reconcile actual vs required screen stacks
• Priority-based modal handling prevents blocking screens from breaking navigation flows

The article reveals a graph-based algorithm for handling deep links that's far more scalable than the naive sequential approach most teams use.