[Experiment] MarkdownTextBlock

[nerocui]

MarkdownTextBlock

Problem Statement

The existing MarkdownTextBlock in the toolkit is old and out of maintenance. It's based on custom parser code and the users have been requesting more features and bug fixes.

Proposed Solution

Since in .NET ecosystem, there's already an existing state of the art markdown library, Markdig, it'd be in our best interest to integrate that into a new MarkdownTextBlock and explore the various possibilities it brings.

Open Questions

• How do we bring the same level of extensibility of the Markdig library to the new MarkdownTextBlock?
• There are some limitations from using RichTextBlock as the rendering target. What's the best way to mitigate them?
• How will this run in Uno Platform if it depends on RichTextBlock?
• What kind of performance metrics are necessary? How do we measure and achieve them?
• What's the accessibility requirement?

Code: https://github.com/CommunityToolkit/Labs-Windows/tree/main/components/MarkdownTextBlock
Initial PR: #480

[JoeTomkinson]

@nerocui can you give us a bit of an update as we're 3 months on from your initial post above, as to what you think the current state of the MarkdownTextBlock is?

I've installed the pre-release '0.1.240517-build.1678' version to take a look at it, can already see some interesting issues with rendering code blocks and when the MarkdownTextBlock is inside of data templates, although still testing as to whether that's an issue specific to being inside of a data template or something related to binding.

[nerocui]

Thanks for your interest in the control. There are some dependency that needs to be fixed first before the code block can function properly. Currently we have the syntax highlighting turned off because of that.

I'm interested in what kind of issue you are seeing when rendering in templates. Could you post them here? I want to collect feedback and improve this control as it's still in an "experiment" phase.

[JoeTomkinson]

I raised an issue initially outlining the main issue that is present in the pre-release NuGet version of the Markdown control. I've included a comment in there as well that outlines a handful of other issues I've noticed so far.

I am going to try and get an environment set-up to start creating PRs against the Labs so I can help out a bit.

[JoeTomkinson]

The issue with rendering inside of the data template was a bit of a red--herring, there's an exception when ApplyText recieves a null string for any reason and that causes it to just stop rendering the rest of the markdown, so just needed a check and return rather than an exception throw.