[Feature]: ReactiveUI.Fody [ReactiveCollection] attribute for adding change notifications from collections

[MGRussell]

The [Reactive] attribute in Fody is extremely handy for reducing boiler plate and clutter, but does not have a comparable partner for observable collections. Would it be reasonable to add a [ReactiveCollection] attribute that results in similar notifications for collection changes?

One implementation idea may be to tie such notifications into a change notification on the property itself, so that if the list is recreated it will continue to deliver notifications: this.WhenAnyValue(x => x.SomeObservableCollection).Do(x => x.CollectionChanged += (_,_) => this.RaisePropertyChanged(nameof(SomeObservableCollection))).Subscribe(); . This would then be added into any constructor which is not called by another constructor.

[tomasfil]

Hello, there is new source generator in works as Glenn noticed here:
https://github.com/reactiveui/ReactiveObject.Generators/issues/1

[ChrisPulman]

Hi, an update to this, the ReactiveUI Source generators are now located here ReactiveUI.SourceGenerators
I will look at the possibilities of adding such a feature to this project.

[ChrisPulman]

reactiveui/ReactiveUI.SourceGenerators#271
This PR intends to introduce the functionality as requested, if accepted this should make it to the next release.