What is the purpose of ReactiveUI's IViewFor<T> (and its implementing types) in WPF? [closed]

Question

I am in the process of learning ReactiveUI and so far I love it but I now realise that the framework encompasses XAML (i.e. the view layer) as well, offering things like ReactiveUserControl and ReactiveView.

Why do I need, or want these? System.Reactive/ReactiveUI offer massive advantages on the Model/ViewModel side but what are the advantages on the View side, again, in the context of a WPF app? Unit testing perhaps?

Note: I like WPF, I like its data binding. All my XAML bindings are strongly-typed and easy to refactor, customise, re-skin, debug and whatnot. I learned to use but not over-use the converters so never have a prob with those either. I never felt a need to override the UserControl class. With that said, I never had a problem with the WPF itself.

If I decide to use the IVIewFor<T> implementations, will my XAML designer go nuts? Will I lose anything? Will I end up debugging memory leaks, UI stutter and strange CPU spikes? We'll be making a very large app so we go by the 'better safe than sorry' principle as we were burnt by the CAB framework before.

If I decide against, what benefits of the ReactiveUI will we lose? Would I be heathens for doing this, or is it more of an optional aspect of the framework?

So far I understand the benefits in case of WinForms or Android (it offers binding support as I understood) but not WPF. While it sure does have its quirks, I don't feel the need for another framework on top of it.

Answer 1

You would implement IViewFor<T> when you for example want to set up bindings in the view and when you want to handle activation and deactivation, e.g.:

this.WhenAnyValue(x => x.ViewModel.Name).BindTo(this, view => view.Name.Text);

this.WhenActivated(d => { /* do something */});

These methods are implemented as extension methods. Please refer to the docs for more information and examples:

https://reactiveui.net/docs/handbook/data-binding/ https://reactiveui.net/docs/handbook/when-activated/

Of course you don't have to use all features of ReactiveUI. It's perfectly fine to set up bindings in the XAML markup as usual and still bind to ReactiveObjects.