- properly labels all the code editor areas (Theme/Plugin, Custom HTML widget, Additional CSS), whether CodeMirror is enabled or disabled
- adds `role="textbox"` and `aria-multiline="true"` to the CodeMirror editing area to allow assistive technologies properly identify it as a textarea
- standardizes the "keyboard trap" help text across the admin and keeps it as a list for better readability
- use the Help text elements as target for `aria-describedby`, to make screen readers read out the help text when focusing the editors
- fixes the `aria-expanded` attribute usage in the Customizer "Additional CSS" help toggle
- moves focus to the CodeMirror editing area when clicking on the associated label
- in the Plugin editor screen: changes a `<big>` element to `<h2>` for better semantics and consistency with the Theme editor screen
- also, removes a few textdomain leftovers, see `better-code-editing` and `default`
Props westonruter, melchoyce, afercia.
Fixes#41872.
Built from https://develop.svn.wordpress.org/trunk@41586
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* Code editor is integrated into the Theme/Plugin Editor, Additional CSS in Customizer, and Custom HTML widget. Code editor is not yet integrated into the post editor, and it may not be until accessibility concerns are addressed.
* The CodeMirror component in the Custom HTML widget is integrated in a similar way to TinyMCE being integrated into the Text widget, adopting the same approach for integrating dynamic JavaScript-initialized fields.
* Linting is performed for JS, CSS, HTML, and JSON via JSHint, CSSLint, HTMLHint, and JSONLint respectively. Linting is not yet supported for PHP.
* When user lacks `unfiltered_html` the capability, the Custom HTML widget will report any Kses-invalid elements and attributes as errors via a custom Kses rule for HTMLHint.
* When linting errors are detected, the user will be prevented from saving the code until the errors are fixed, reducing instances of broken websites.
* The placeholder value is removed from Custom CSS in favor of a fleshed-out section description which now auto-expands when the CSS field is empty. See #39892.
* The CodeMirror library is included as `wp.CodeMirror` to prevent conflicts with any existing `CodeMirror` global.
* An `wp.codeEditor.initialize()` API in JS is provided to convert a `textarea` into CodeMirror, with a `wp_enqueue_code_editor()` function in PHP to manage enqueueing the assets and settings needed to edit a given type of code.
* A user preference is added to manage whether or not "syntax highlighting" is enabled. The feature is opt-out, being enabled by default.
* Allowed file extensions in the theme and plugin editors have been updated to include formats which CodeMirror has modes for: `conf`, `css`, `diff`, `patch`, `html`, `htm`, `http`, `js`, `json`, `jsx`, `less`, `md`, `php`, `phtml`, `php3`, `php4`, `php5`, `php7`, `phps`, `scss`, `sass`, `sh`, `bash`, `sql`, `svg`, `xml`, `yml`, `yaml`, `txt`.
Props westonruter, georgestephanis, obenland, melchoyce, pixolin, mizejewski, michelleweber, afercia, grahamarmfield, samikeijonen, rianrietveld, iseulde.
See #38707.
Fixes#12423, #39892.
Built from https://develop.svn.wordpress.org/trunk@41376
git-svn-id: http://core.svn.wordpress.org/trunk@41209 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Andrea Fercia
Weston Ruter