ReactiveUI

Talk I gave at QCon SF - demo is at https://github.com/reactiveui/RxUI_QCon. Make sure to view each commit in order, as it's a step of the demo!

Transcript

1. Reactive Extensions and ReactiveUI
2. github @xpaulbettsx
3. A Model-View-ViewModel framework for native (non-web) applications.. ...that integrates the Reactive Extensions for .NET. What is ReactiveUI
4. Write completely non-blocking UIs whose interactions are described in a declarative fashion, and be able to test long-running timelines instantly using virtual time Why is that cool?
5. Not just limited to XAML! • ReactiveUI works even on non-XAML platforms • Preliminary support for Cocoa / UIKit, GTK#, and Android • Runs on .NET 4.0, .NET 4.5, Silverlight 5, WP7, WP8, Metro / WinRT, and Mono
6. Code in XAML code-behind is untestable - let’s move as much of our behavior into a separate object that we can test, and abstract away commands from how they’re invoked (button clicks) MVVM
7. ReactiveUI bridges Properties and Observables
8. WhenAny
9. WhenAny
10. WhenAny
11. WhenAny
12. How WhenAny Works • WhenAny determines at runtime how to be notified for a property change on an object • INotifyPropertyChanged • DependencyObjects (XAML) • Key-Value Observing (Cocoa)
13. ToProperty
14. ToProperty
15. OAPH • Subscribes to an IObservable for you and “pipes” it to a property • Makes sure that notifications come back on the UI thread
16. WhenAny and ToProperty fit together like tea and crumpets
17. WhenAny + ToProperty
18. WhenAny + ToProperty
19. WhenAny + ToProperty
20. ReactiveUI bridges Commands and Observables
21. ReactiveCommand = Subject + ICommand • Implements WPF’s ICommand • Is also an IObservable<object>
22. ReactiveCommand
23. ReactiveCommand helps you to decouple Views and ViewModels
24. Doesn’t ICommand have a CanExecute too?
25. CanExecute is IObservable<bool> • You can source this IObservable from anywhere • One particularly useful place, is from WhenAny
26. CanExecute
27. Demo!