Added OnNavigatingFrom extension for popup related navigation

[dartasen]

Description of Change

Added an extension method to OnNavigatingFrom event which checks if the destination page is a popup and if so returns true.

Currently one of the test is failing because MAUI OnNavigatingFromEventArgs seems to provide a wrong DestinationPage argument. Rather than acting like OnNavigatedFrom, it gives the CurrentPage rather than the real navigation destination.

I opened an issue : dotnet/maui#34073

Linked Issues

• Fixes Extend NavigatingFromEventArgs from OnNavigatingFromto allow determine if DestinationPage is Popup #3090

PR Checklist

• Has a linked Issue, and the Issue has been approved(bug) or Championed (feature/proposal)
• Has tests (if omitted, state reason in description)
• Has samples (if omitted, state reason in description)
• Rebased on top of main at time of PR
• Changes adhere to coding standard
• Documentation created or updated: Update MAUI Popup documentation for OnNavigatingFrom extension MicrosoftDocs/CommunityToolkit#617

Additional information

[Copilot]

Pull request overview

This pull request adds an extension method for the OnNavigatingFrom navigation event to detect when navigation is transitioning to a Community Toolkit Popup. The implementation mirrors the existing NavigatedFromEventArgsExtensions but operates during the "navigating" phase rather than the "navigated" phase, allowing developers to detect popup navigation before it completes.

Changes:

• Added NavigatingFromEventArgsExtensions.shared.cs with IsDestinationPageACommunityToolkitPopupPage() extension method
• Updated documentation in NavigatedFromEventArgsExtensions.shared.cs for consistency
• Added comprehensive unit tests in NavigatingFromEventArgsExtensionsTests.cs with positive and negative test cases

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
NavigatingFromEventArgsExtensions.shared.cs	New extension class providing IsDestinationPageACommunityToolkitPopupPage() method to detect popup navigation during the navigating phase
NavigatedFromEventArgsExtensions.shared.cs	Updated documentation comments to use "if" instead of "whether" for consistency with the new extension method
NavigatingFromEventArgsExtensionsTests.cs	Added unit tests covering both true and false cases for popup detection during navigation

[TheCodeTraveler]

Thanks @dartasen!! Approved ✅

Could you please also open a Docs PR on our official documentation repo? https://github.com/MicrosoftDocs/CommunityToolkit/pulls

Once the Docs PR is submitted, I can merge the code here. I plan on releasing CommunityToolkit.Maui v14.0.1 this week once Microsoft.Maui.Controls v10.0.41 is released. If you're able to get the Docs PR in before Friday, we'll include this in the scheduled release and publish it as CommunityToolkit.Maui v14.1.0 instead!

[dartasen]

Thank's @TheCodeTraveler, will look at adding the documentation tomorrow !

However what's the approach you wanna take here ?
Currently the UnitTests are failing until OnNavigatingFrom get fixes in MAUI.
Should I remove them and file an issue to add them back as soon as it's fixed ?

[dartasen]

Added the documentation 😄

[TheCodeTraveler]

Currently the UnitTests are failing until dotnet/maui#34073 get fixes in MAUI

Oh wow - strange! Yea, you're totally right. This is a bug in .NET MAUI: NavigatingFromEventArgs.DestinationPage is actually providing the previous page. Testing it alongside NavigatedFromEventArgs.DestinationPage, we confirm that NavigatingFromEventArgs.DestinationPage provides the destination page.

I confirmed that the unit test is accurate. I also implemented OnNavigatingFrom in the Sample app to confirm it wasn't just a bad test.

Screenshots of Bug

Here's two screenshots showing a breakpoint triggering when I display SimplePopup from our Popups Page in the sample app:

NavigatingFromEventArgs.DestinationPage Incorrect	NavigatedFromEventArgs.DestinationPage Incorrect

And here's a GIF demonstrating that we are correctly navigating to a PopupPage but NavigatingFromEventArgs is proving the incorrect value its DestinationPage property.

Next Steps

In the meantime, I'll convert this PR to a draft and keep an eye on the Issue you opened. Once that Issue is fixed, we'll merge this PR 🙌