Move C# Markup Extensions from Forms to Toolkit

[jfversluis]

Summary

The C# Markup Extensions in its current form need to move from Forms into the Toolkit.

We want to add this in a separate package from the main one and therefore also a separate (new) namespace

[VincentH-Net]

Still blocked by xamarin/Xamarin.Forms#12136

[VincentH-Net]

Here is the source for C# Markup including CSharpForMarkup Part 2 PR features, in a single commit:

VincentH-Net/Xamarin.Forms@939150d

• Separated C# Markup API + unit tests from Forms projects
• Fully working with 100% code coverage, all tests green
• Using IVT from Forms while waiting for [Spec] APIS That need to be made public for contributors and Xamarin Community Tookit Xamarin.Forms#12136

[jsuarezruiz]

@VincentH-Net I would like to know how I can help you to move the CSharpForMarkup to the XCT. XCT was recently added to the .NET Foundation and a Support document has been created https://github.com/xamarin/XamarinCommunityToolkit/blob/main/Support.md
@ahoefling Could you share the PRs you created (related with the Popup Control)?. I would like to update the list of blocking points, which have PR and which are still pending.

[VincentH-Net]

Thanks for your offer @jsuarezruiz! This is how we could get it done:

1. Could you create a PR in Forms 5 to make the API's listed in [Spec] APIS That need to be made public for contributors and Xamarin Community Tookit Xamarin.Forms#12136 public (just the ones needed for C# Markup)?

2. After that I can update the above C# Markup source to your Forms PR branch and make a PR against XCT (this means that the C# Markup XCT package will depend on Forms 5; since it is it's own package without any dependencies on other XCT packages, we can release this even before the main XCT package supports Forms 5).

3. After this you can submit your PR and get it merged

4. After your Forms PR is merged I can update my XCT PR to the public Forms NuGets and submit it

Tbc the Xamarin.Forms.Core API's that C# Markup itself needs access to are:

Internal

• Binding.SelfPath constant
• GestureRecognizer default ctor
• NullEffect class
• IPaddingElement interface

Private

• FontElement class
• PaddingElement class

In addition, the C# Markup unit tests need to access below API's. If that would be preferred by the team, we could opt to keep below API's as they are, and use reflection in XCT unit tests to access them. Since we won't ship the unit tests, that would not introduce any risks for XCT users.

Xamarin.Forms.Core.UnitTests Internal:

• RelativeLayoutTests.UnitExpressionSearch class

Xamarin.Forms.Core private API's on BindableObject:

• GetContext method
• BindableContextAttributes enum
• BindablePropertyContext nested class
• SetValueArgs nested class

[SkyeHoefling]

@jsuarezruiz

Could you share the PRs you created (related with the Popup Control)?

I have submitted a PR to XCT yet as it needs to support Xamarin.Forms 5.0. The original PR for Popup Control in Xamarin Forms is xamarin/Xamarin.Forms#9616.

As of today the only outstanding PR I have to Xamarin.Forms is opening up a few APIs to allow UWP support xamarin/Xamarin.Forms#12279.

Popup Control Ready Platform
The table below designates which platforms are ready for development once XCT support Xamarin.Forms 5.0

Platform	Status
Android	✔ Ready
iOS	✔ Ready
UWP	🔃 Waiting for PR

I haven't submitted any PR to XCT for the Popup Control, once we get a branch that support Xamarin.Forms 5.0 I can start submitting PRs

[pictos]

I think that we can create a branch here targeting Forms 5.0. FYI, The last time that I did it I face some issues with PancakeView and controls can have an odd behavior (like camera view)