WPF Gap: CollectionViewSource doesn't support all WPF scenarios

Proposal: CollectionViewSource doesn’t support all WPF scenarios

Summary

The CollectionViewSource in UWP is inferior to the one in WPF doc here.

The WPF one supports live filtering, grouping, and sorting all out of the box. The UWP one does not. ☹

For instance, this DataGrid grouping scenario is not easily achievable in UWP.

Rationale

Creating sorted, grouped, and/or filtered lists in UWP is a pain, especially trying to combine any combination of these. The CollectionViewSource is supposed to be this abstraction above the data layer itself. UWP/WinUI should provide a first/best-in-class solution to these common scenarios and match or improve upon the WPF APIs.

Scope

Capability	Priority
Allow (Live) Grouping	Must
Allow (Live) Sorting	Must
Allow (Live) Filtering	Must
Allow any combination of the three to work in tandum together	Must
Able to configure CVS in XAML	Should

[kateryna-novak]

@kateryna-novak if you just need grouping, there’s the ObservableGroup option as well as shown in the MVVM Toolkit app Collection sample: https://aka.ms/mvvmtoolkit/app

@michael-hawker I need filtering and grouping. That’s why I’m asking.

[michael-hawker]

@LadderLogic I own the Windows Community Toolkit, so I don’t know if there’s plans on the WinUI side to work on this in the near future or not. I don’t think @anawishnoff is the correct owner for this anymore, @gabbybilka who should own this now?

We have an AdvancedCollectionView in the Toolkit, but it doesn’t cover all the scenarios currently (thus why I opened this issue for tracking with the platform).

I’m not too sure where our gaps lie currently as we have some other helpers we’ve developed since for grouping scenarios. We want to improve our samples more later this year with our next release, so we’ll have a better understanding then. I know @Sergio0694 has been making some examples of these scenarios for the MVVM Toolkit Samples, but not sure if they’re merged into main yet or just in a PR.