Source generated sample registration

[Arlodotexe]

Overview

• Closes Investigate non-reflection alternatives to current sample system #18
• Adds a source generator - crawls for ToolkitSampleAttribute and generates a method that returns metadata for all found.
• Removed reflection-based sample discovery - in favor of the source generated sample data.
• Adds C# 10 - to CommunityToolkit.Labs.Core only.
• Adds IsExternalInit - Polyfill was needed to use Records.
• Has been tested - all project heads have been tested and work with the new code.

Functional example

With temporary second sample control added

Attributes

Generated code

Full circle

[michael-hawker]

UWP compile issue: MainPage.xaml.cs:77 selectedMetadata.Type wasn't updated to SampleControlType?

Should be:

var controlInstance = Activator.CreateInstance(selectedMetadata.SampleControlType);

In CommunityToolkit.Labs.Uwp. didn't see file changed in PR so I couldn't make a suggestion.

Otherwise, I think this is pretty cool, and I think good to go! Assuming this is Source Generator V2 vs V1?

I also know you wanted @Sergio0694 to take a quick look too for his input as the Source Generator ninja... 😋

[Arlodotexe]

@michael-hawker Good catch, looks like merged code that didn't get updated. Build validation would be nice here haha.

@Sergio0694 Any feedback at all? I could probably make the source generator incremental but this is a pretty slim generator.

[michael-hawker]

@Arlodotexe I know the main thing with the original source generators is that it doesn't matter if it doesn't do a lot of work if the solution/project is large enough it's still trying to run it on everything all the time. But maybe we won't have a big problem in Labs?

[Arlodotexe]

@Arlodotexe I know the main thing with the original source generators is that it doesn't matter if it doesn't do a lot of work if the solution/project is large enough it's still trying to run it on everything all the time. But maybe we won't have a big problem in Labs?

I had an incremental version at one point, but it was difficult to debug so I swapped to the regular ones. Code should be clean enough to make switching pretty painless if we start seeing issues.

[Sergio0694]

The generator seems fine for what it needs to do, other than it not being incremental. Left a few notes here and there with some questions, but overall it looks ok at least for now. Note for the future, please consider documenting your code better 😅

[Sergio0694]

Seems fine, just left another couple of nits 👍