Cancellable Flows in Kotlin Coroutines: The Complete Guide
Article Summary
Kotlin Flow cancellation isn't just calling cancel() and hoping for the best. Sahil Thakar breaks down 11 sophisticated techniques that prevent memory leaks and save battery life.
This comprehensive guide from droidcon explores Flow cancellation in Kotlin Coroutines, covering everything from basic job cancellation to advanced operators like transformWhile and collectLatest. Each technique includes practical code examples and real-world use cases.
Key Takeaways
- Job cancellation stops flows at suspension points like delay() and emit()
- withTimeout throws exceptions; withTimeoutOrNull returns null gracefully
- takeWhile stops flows completely; filter continues but skips values
- collectLatest cancels previous collection when new values emit
- ensureActive() makes CPU-intensive flows respect cancellation signals
Critical Insight
Choosing the right Flow cancellation technique based on your use case (lifecycle management, timeouts, conditions, or count limits) dramatically improves Android app performance and resource management.
