Demo Page: Give user feedback when "options" is not valid JSON.

[aprotim]

Marked version:

Commit: da9d155

Markdown flavor: all

Description

When the "options" object provided by users doesn't parse, make the input field red to let them know:

And when it does parse, return to a regular old textarea.

Expectation

Some kind of visual indication that the options entered into the text box aren't valid.

Result

No such indication.

What was attempted

https://marked.js.org/demo/?text=%23%23%23%20These%20options%20don%27t%20work.&options=a

Contributor

• Test(s) exist to ensure functionality and minimize regression (if no tests added, list tests covering this PR); or,
• no tests required for this PR.
• If submitting new feature, it has been documented in the appropriate places.

Committer

In most cases, this should be a different person than the contributor.

• Draft GitHub release notes have been updated.
• CI is green (no forced merge required).
• Merge PR

[styfle]

Great! 🎉

[UziTech]

Great work. I'm wondering if there is also a way we can allow them to choose the version on marked that they want to use.