Remove dart:html page

[MaryaBelanger]

• Removed dart:html page from sidenav
  • Replaced with dart:js_interop
• Removed dart:html from libraries overview page
  • Replaced with dart:js_interop
• Add prev/next to js interop pages
  • (so the js interop overview page will lead to the rest of the js content, even from its place in the libraries section)

Fixes #6314

[dart-github-bot]

Visit the preview URL for this PR (updated for commit 0253bae):

https://dart-dev--pr6345-rm-html-0n7vheaq.web.app

[MaryaBelanger]

@parlough So I removed the dart:html page from the side nav, but didn't address the redirects: one in firebase.json, many in library-tour-redirector.js. I wasn't sure what to do, especially with the latter, because it's pointing to specific sections on the dart:html page that don't necessarily have equivalents on the package:web page. Should we address that or is it safe to leave it alone?

[MaryaBelanger]

@srujzs Can you advise on the deprecation wording I left in a couple places:

• On the libraries Overview page

   dart:js_interop
       DOM and other APIs for browser-based apps. dart:js_interop replaces dart:html.
  

• And on the dart:html page (which still exists but won't be discoverable):

   The dart:html library is deprecated. Instead, use dart:js_interop or package:web.
  

I'm mostly wondering if I should say "dart:js_interop and package:web replace dart:html"? Or does the former imply the latter? Is "replace" the right word, or should we be saying more?

Edit: Another I just added:

• On the Overview page:

  * HTML elements and other resources for web-based applications that need to
  interact with the browser and the Document Object Model (DOM)
  (`dart:js_interop` and `package:web`)
  

[parlough]

@parlough So I removed the dart:html page from the side nav, but didn't address the redirects: one in firebase.json, many in library-tour-redirector.js. I wasn't sure what to do, especially with the latter, because it's pointing to specific sections on the dart:html page that don't necessarily have equivalents on the package:web page. Should we address that or is it safe to leave it alone?

+1 Good idea to remove it from the sidenav and keep it around for now :)

I think it's safe to leave library-tour-redirector.js alone. It's handling old, outdated links and we'll eventually remove it.

As for the existing redirects in firebase.json, consider updating them to point the package:web page?

[parlough]

Thanks Marya! Just a few small suggestions to consider.

---

Continuing our long good bye of dart:html 👋 🥹

[srujzs]

"dart:js_interop and package:web replace dart:html"

I prefer this. While it's true dart:js_interop/_unsafe is the only interop mechanism users can or should use anymore, the natural question will be "where are all the browser APIs?" :).

[srujzs]

Thanks Marya!