Fail better — Presenting errors in Cocoa

It's OK for software to fail — but it should display helpful errors. And the "helpful" part is not optional.

-presentError: is a nice way to build powerful mechanisms for presenting helpful errors in Cocoa applications.

The "Demo" part is available on GitHub: github.com/kemenaran/ios-presentError . A good implementation of -presentError: on iOS is available there: github.com/hectr/ErrorKit

Transcript

1. Fail better CocoaHeads Paris “Ever tried. Ever failed. No matter. Try Again. Fail again. Fail better.” Samuel Beckett
2. presentError:
3. Introduced in Mac OS 10.4
4. -[NSResponder presentError:]
5. Follows the responder chain
6. -[NSResponder willPresentError:]
7. From http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/ ErrorHandlingCocoa/ErrorHandling/ErrorHandling.html
8. From http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/ ErrorHandlingCocoa/ErrorHandling/ErrorHandling.html
9. Why so cool?
10. Contextualization!
11. 1. Level of information 2. Visual context
12. 1. Level of information “I want errors precise, but still understandable”
13. ➤ generate precise errors ➤ rewrite errors for to the context
14. 2. Visual context “Where did this error occur?”
15. ➤ embedding errors in the UI
18. Available on UIResponder too !
19. Available on UIResponder too !
20. Re-implement!
21. Demo
22. Links github.com/kemenaran/ios-presentError github.com/hectr/ErrorKit
23. pierre@capitainetrain.com
24. Thanks