Widgets: text widget and media widgets cannot be edited in accessibility mode

[designsimply]

Steps to reproduce:

1. Go to WP-Admin ->Appearance ->Widgets.
2. Add a text widget to any widget area and add some content.
3. Click on Screen Options at the top of the page and enable Accessibility Mode.
4. Attempt to edit the widget.

Result: there were options to move the widget to different widget areas, but no option to edit the widget itself. The following error appears in the console:

TypeError: b is not a constructor
tinymce.min.js:13:11887

Video: ​1m9s

^{Seen at ​http://alittletestblog.com/wp-admin/widgets.php?editwidget=text-3&sidebar=sidebar-1&key=0 using Firefox 53.0.3 on Mac OS X 10.12.5 on a site running WordPress 4.9-alpha-40885.}

/hat tip @kokkieh for reporting the issue.

[afercia]

Can confirm 😞 Regression from 4.7. See below how the previous text widget looked like in the accessibility mode in WP 4.7:

[westonruter]

It's also a problem for the media widgets (image, video, audio)

I don't, however, get any JS error.

[westonruter]

​https://github.com/xwp/wordpress-develop/pull/234

[westonruter]

@afercia @designsimply please give 40986.0.diff​ a try. It should fix the Text widget and Media widgets so that they work on the widgets admin screen in accessibility mode, while also working without the mode and also working in the customizer.

[afercia]

@westonruter looks good to me, tested a bit also on Windows IE 11 👍
About $( window ).load() shouldn't that just be changed to on()? See for example #25371.

[afercia]

Looking a bit into the history of the Widgets screen "accessibility mode", it was introduced in [11503] and it's basically the no-js fallback of this screen. All the "classical" widgets can be edited also when JS is off, while the new ones are JS-based.
When the "accessibility mode" is on, the main widgets JavaScript file doesn't get enqueued and the Widgets screen is fully functional, it just works without the JS enhancement. So I'm wondering what the no-js fallback should be for the new widgets: they can still be repositioned but there's no way to edit their content. Should a no-js fallback be provided in the first place? Should the new widgets be hidden when no-js? Should a warning appear? Or...? From a more general perspective, is WordPress still aiming to provide no-js fallbacks in a future where many UI components will be built with JS?

[westonruter]

I think a no-JS fallback should be considered passé.

[westonruter]

In 40941:

Widgets: Add accessibility mode support for TinyMCE-enhanced Text and Media widgets (Video, Audio, Images).

Amends [40640], [40631].
Props westonruter, afercia.
See #35243, #32417.
Fixes #40986.

[westonruter]

Re-opening for 4.8.1.

[afercia]

I think a no-JS fallback should be considered passé.

I tend to agree, however I think WordPress should consider to announce publicly that from now on a no-js fallback is not guaranteed, as this is a big shift from the development practices adopted in the last years.

[westonruter]

In 41051:

Widgets: Add accessibility mode support for TinyMCE-enhanced Text and Media widgets (Video, Audio, Images).

Merges [40941] to 4.8 branch.
Amends [40640], [40631].
Props westonruter, afercia.
See #35243, #32417.
Fixes #40986 for 4.8.1.