Weak PropertyChanged on ObservableObject

[GalaxiaGuy]

I'm currently using ObservableObject from Xamarin Community Toolkit. The implementation is very similar to the ObservableObject here, but one interesting difference is that PropertyChanged event is implemented using a weak event manager implementation.

https://github.com/xamarin/XamarinCommunityToolkit/blob/main/src/CommunityToolkit/Xamarin.CommunityToolkit/ObjectModel/ObservableObject.shared.cs

Is there any possibility of bringing a weak PropertyChanged version of ObservableObject here?

Xamarin Community Toolkit has its own DelegateWeakEventManager which would also need implementing.

https://github.com/xamarin/XamarinCommunityToolkit/blob/main/src/CommunityToolkit/Xamarin.CommunityToolkit/Helpers/DelegateWeakEventManager.shared.cs

There is a conversation here about bringing such a class directly into the BCL, but I would guess it would be quicker and easier to add it here (even if it becomes obsolete in the future).

As another aside, on the MAUI front, DelegateWeakEventManager has been promoted to the main MAUI repo. There is a discussion going on there about the possibility of depending on .NET Community Toolkit (for the main purpose of using the IMessenger) but if it does happen, then it could drop it's DelegateWeakEventManager in favour of using one here, if it gets added.

dotnet/maui#3880

[maxkoshevoi]

In the meanwhile you can use WeakSubscribe as a workaround. It acomplishes the same thing as ObservableObject with WeekEventManager underneath.

It's marked as Obsolete because XCT already has ObervableObject with WeekEventManager underneath, and if publisher and consumer are both week - subscribtion is removed after 1st GC run. You need to use one or the other, but not both: xamarin/XamarinCommunityToolkit#1001

[GalaxiaGuy]

Using a different way of subscribing as a work around is not really an option, since I may not be in control of the code that is doing the subscribing .

[GalaxiaGuy]

Would it be possible to make ObservableObject.PropertyChanged and ObservableObject.PropertyChanging virtual? That way a consumer could override them to use DelegateWeakEventManager.