Your Life With (and Without) Observation
summary
Observation replaces ObservableObject for SwiftUI state, ships in Swift 5.9 as part of the stdlib and requires iOS 17+, uses opt-out by default macros that compile into getters/setters calling a per-instance registar and a thread-local access list to record accessed keypaths, then installs observations to call onChange only for actual property changes. It supports nested optionals and collections, forbids lazy/custom property wrappers and no value types, and Xcode 15 can expand the macros so the generated code is debuggable.
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chapters (14)
- 0:00Introduction to observation
- 1:22Limitations of ObservableObject
- 3:28Observable vs ObservableObject
- 5:12Under the hood of Observation
- 8:06Registrars and access lists
- 11:06Observation tracking
- 13:44Tracking implementation
- 17:31Summary of tracking workflow
- 18:50Migration and pitfalls
- 21:57State vs. Identity
- 24:06Real world animation examples
- 27:13Escaping content closures
- 31:11Limitations and takeaways
- 33:13Q&A and conclusion
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