Roadmap to CKEditor 5 stable in Drupal 9

Added:

2. Obsoleteness of upgrade path in Drupal 11:
   1. #3239012: [11.x] Remove the CKEditor 4 upgrade path

Documentation gates are complete as of yesterday.

Moving things into core that can only happen once it is in core:

is done.

Added #3228505: Plugin definition DX: automatically check for plugin definitions whether their ::getDefaultSettings() matches the config schema to Test coverage, reliability and maintainability matching or exceeding CKEditor 4's.

#3226335: Follow-up for #3216015: allow contrib & custom Drupal modules providing CKEditor 4 plugins to specify their CKEditor 5 equivalents + settings to be migrated and #3226694: Follow-up for #3216015: refactor SmartDefaultSettings to return messages rather than sending them landed yesterday, together they make the 4-to-5 upgrade path entirely possible and testable!

Fix parent issue 😅

Long overdue for another roadmap update. Many dozens of issues fixed since then. Not focusing on what's been done, but on the work we identified.

Edge cases:

• Bugs encountered and fixed in since #6, which I'm not going to add to the roadmap:
  #3239376: [unbreak tests] SA-CORE-2021-009 broke tests, #3244911: Automatic upgrade path failing when CKEditor 4 has the StylesCombo plugin configured, #3245387: CKEditor5 has an empty settingsForm() method that neither inherits from nor is called by anything, #3245390: CKEditor5::validatePair() and CKEditor5PluginManager::getPluginConfiguration() throw inconsistent exception types, #3245772: Update CKEditor5AllowedTagsTest following the commit of #2763075 into Drupal 9.3, #3246448: Fix cspell & phpcs failures caused by both becoming more strict, #3246647: Filter settings are not removed when a filter is disabled, #3246955: Harden drupal-media by namespacing model attributes
• Not added to roadmap because it is part of the transition to core: https://www.drupal.org/project/ckeditor5/issues/3243869
• Discussions opened by core committer @effulgentsia as part of the core review process, but next steps are not yet clear, hence not yet added to the roadmap: #3246012: Consider changing CKEditor5PluginElementsSubsetInterface to not extend CKEditor5PluginConfigurableInterface, #3246021: Consider removing the special casing of "ckeditor5_sourceEditing" within CKEditor5PluginManager::getProvidedElements(), #3246246: CKEditor 5 plugins needing more complex conditions — all 3 are awaiting feedback from both @effulgentsia as well as other CKEditor 5 module contributors.

Added:

1. Ensure that sites can update from using CKE4 to CKE5 safely when using no contributed CKEditor modules
   • #3245079: Automatic upgrade path always enables all <h*> tags when only >=1 was enabled before
   • #3245320: Automatic upgrade path always disables image uploads — in the UI

2. Ensure contrib modules can do everything: translations, automatic upgrade path from CKE4 …
   • #3245723: Follow-up for #3201637: omitting PrimitiveTypeConstraint violations for filter settings is implemented too broadly
   • #3245807: DX: allow contrib modules to subclass \Drupal\Tests\ckeditor5\Kernel\ValidatorsTest

3. Ensure CKE5 equivalent plugins of CKE4 generate/support equivalent markup
   • #3246168: Images are not linkable through UI; already linked images are unlinked (data loss!)
   • #3246169: Embedded media are not linkable through UI; already linked embedded media are unlinked (data loss!)
   • #3247246: Attribute value encoding not compatible with Xss::filter()
   • #3247634: [upstream] [drupalImage] Unlinking linked inline images while GHS is enabled: wrapping <a> is impossible to remove

4. Ensure CKE5 functionality matches that of Drupal core's CKE4:
   • #3245720: [drupalMedia] Support choosing a view mode for <drupal-media>
   • #3245950: [upstream] <script> tag support in GHS
   • #3246365: [drupalMedia] Show the Image Media's default alt text that is being overridden
   • #3246380: [drupalMedia] Media previews do not update after alt text was modified
   • #3246385: [drupalMedia] Support captions on <drupal-media>

5. Documentation gates
   • #3243850: hook_ckeditor5_plugin_info_alter()'s example sets ['drupal']['config'], but that's not one of the documented definition properties

8. Accessibility
   • #3239423: Toolbar UI accessibility review: round 2
   • #3245735: Follow-up for #3222852: validation errors are not associated with the correct form element
   • #3246188: Vertical tabs auto collapse on viewports smaller than 1360px on certain configuration actions

9. Test coverage, reliability and maintainability matching or exceeding CKEditor 4's:
   • #3243867: ckeditor5_module_implements_alter() looks like it has incorrect logic
   • #3245400: Add an @throws PHPDoc everywhere exceptions are thrown
   • #3246280: Defense in depth: add anti-CSRF token to this module's routes
   • #3246521: Make plugin.manager.ckeditor4to5upgrade.plugin a private service
   • #3246524: Make more (all?) classes @internal
   • #3247683: Disable CKEditor 5's automatic link decorators (in Drupal filters should be used instead)
   • #3247711: Simplify and accelerate builds: update our use of the CKEditor 5 DLL manifest
   • #3248188: Plugin definition DX: validate drupal.conditions

11. Superior configuration UX:
    • #3245967: Messages upon switching to CKEditor 5 are overwhelming
    • #3248177: Language toolbar item cannot be removed from the toolbar

Post-stable, Upstream improvements that would simplify or improve CKEditor 5:

8. #3246260: Simplify CKEditor5ImageController once #2940383 lands

#3249240: HTMLRestrictionsUtilities:: providedElementsAttributes() causes deprecations on PHP 8.1 has been fixed since.

#3224261: [PP-1] Front-end performance: concatenate CKEditor 5 JS assets for every unique configuration was not in here yet, and IMHO is pretty damn important! Added that to Ensure CKE5 functionality matches that of Drupal core's CKE4:.

#15: there's no separate issue for that. ckeditor.module will be removed from Drupal 10. As part of removing that module, we'll also need to change the Standard install profile to use ckeditor5.module instead.

I'd swear such an issue already existed, but I cannot find it right now. Maybe @xjm knows? 🤞

Two new stable-blockers discovered:

1. Added #3256566: [upstream] <style> tag support in GHS to Ensure CKE5 functionality matches that of Drupal core's CKE4.
2. Added #3258030: Text fields using CKEditor 5 do not get visual error indicator to Accessibility.

#3228778: Drupal-specific CKEditor 5 plugins should be able to use Drupal's JS translation API: Drupal.t() landed, which means that only two issues remain under Ensure contrib modules can do everything: translations, automatic upgrade path from CKE4 …:

• #3228464: API for contrib projects to load CKEditor translations
• #3248430: Improve Drupal.ckeditor5 documentation

Landed:

• Contrib enablement: #3228778: Drupal-specific CKEditor 5 plugins should be able to use Drupal's JS translation API: Drupal.t()
• Accessibility: #3238257: Fragment link pointing to <textarea> should be redirected to CKEditor 5 instance when CKEditor 5 replaced that textarea
• Test coverage/DX: #3248188: Plugin definition DX: validate drupal.conditions

New and landed:

• Accessibility: #3258668: Extraneous closing parentheses and curly brace in visually-hidden button description text
• Test coverage: #3259174: Add missing CKE5 SmartDefaultSettings test coverage (wildcard tag with unsupported attribute)

Added #3263384: Add ckeditor5-code-block package and CodeBlock plugin to Ensure CKE5 functionality matches that of Drupal core's CKE4.

#21: Agreed — @tim.plunkett is going to have a go at that 😊

Thanks, @tim.plunkett!

• #3260554: [drupalMedia] Support alignment on <drupal-media> was not in here because it was split from #3246385: [drupalMedia] Support captions on <drupal-media>.
• #3231321: Improve keyboard accessibility in a particular edge case and #3261942: Compatibility issues with inline form errors were newly discovered a11y bugs.

#3224261: [PP-1] Front-end performance: concatenate CKEditor 5 JS assets for every unique configuration falls in the "performance" bucket.

#3228334: Refactor HTMLRestrictionsUtilities to a HtmlRestrictions value object landed.

Added two new stable blocking bugs:

1. Performance: #3260032: CKEditor 5 adds ie11.user.warnings library to every page, triggering a FOUC even for anonymous users
2. Test coverage, reliability and maintainability matching or exceeding CKEditor 4's: #3265626: Changes to "Manually editable HTML tags" lost if form is submitted without triggering AJAX

Two more finished:

• #3228464: API for contrib projects to load CKEditor translations
• #3224652: [drupalImage] Add ckeditor5-image's imageresize plugin to allow image resizing

Three outdated (irrelevant now or done in other issue):

• #3246380: [drupalMedia] Media previews do not update after alt text was modified was completed as part of #3262492: Refactor isMediaUrl to more generic API that supplies frontend metadata about media entities
• #3218297: Voiceover + Safari reads aria-describedby twice when focusing toolbar button is outdated/irrelevant now — the markup structure changed a few times since that issue was filed.
• #3206523: Add FunctionalJavascript test coverage for image upload is outdated — it was finished even before CKEditor 5 was added to Drupal core.

#3246188: Vertical tabs auto collapse on viewports smaller than 1360px on certain configuration actions is a Claro bug, not a CKEditor 5 issue.

Removing it from this roadmap.

#29 added two new major stable blocking bugs. But there are more that we created in the past few weeks. (More to follow tomorrow, but here's what I gathered so far.)

• Ensure CKE5 functionality matches that of Drupal core's CKE4: #3264727: [drupalMedia|drupalImage] Allow removing data-align in the UI, and making an image inline
• Ensure CKE5 equivalent plugins of CKE4 generate/support equivalent markup: #3228691: Restrict allowed additional attributes to prevent self XSS

#3248440: [drupalMedia] Media embed attributes are rendered in container div in editing view landed.

#3259493: [GHS] Unable to limit attribute values: ::allowedElementsStringToHtmlSupportConfig() does not generate configuration that CKEditor 5 expects just landed and was still missing here. It also unblocks #3260853: [GHS] Partial wildcard attributes (<foo data-*>, <foo *-bar-*>, <foo *-bar>) and attribute values (<h2 id="jump-*">) not yet supported and #3260869: Resolve mismatch between <$block> interpretation by CKEditor 5 and Drupal, both of which were missing from the roadmap.

#3246385: [drupalMedia] Support captions on <drupal-media> landed!

#3224261: [PP-1] Front-end performance: concatenate CKEditor 5 JS assets for every unique configuration is blocked on #3232810: [PP-1] Allow setting aggregation groups for js files in library definitions, which is an asset library system component issue, not ckeditor5.module.

A key part was split off from #3224261: #3264512: Enable aggregation for CKEditor 5 assets. This already improves front-end performance significantly: from "bad" to "good". #3224261: [PP-1] Front-end performance: concatenate CKEditor 5 JS assets for every unique configuration will get us from "good" to "optimal".

Therefore I propose moving #3224261: [PP-1] Front-end performance: concatenate CKEditor 5 JS assets for every unique configuration from stable blocking to post-stable. @nod_, @catch, @lauriii: thoughts?

👍, moved #3224261: [PP-1] Front-end performance: concatenate CKEditor 5 JS assets for every unique configuration to post-stable!

#3246365: [drupalMedia] Show the Image Media's default alt text that is being overridden landed!

I was the only person advocating for

7. Media improvements
   1. #3196593: Ease the transition to Media: save image uploads in CKEditor 5 as media entities when media is enabled? (or module specific solution if core issue won't land)
   2. #3073901: Determine an upgrade path from CKEditor image button to media library (or module specific solution if core issue won't land)

to be stable blockers. I advocated for that for a long time:

• 3 years ago: #3073901-2: Determine an upgrade path from CKEditor image button to media library:
  

  My perspective: Standard should remove DrupalImage and stop allowing <img>, and add DrupalMediaLibrary, the media_embed filter and allow <drupal-media>.

• 4 months ago: #3073901-27: Determine an upgrade path from CKEditor image button to media library:
  

  Ideally we'd figure this out before Drupal 10, because Drupal 10 will drop support for CKEditor 4. See #3231364: Add CKEditor 5 module to Drupal core.

  The CKEditor 5 module already has the infrastructure it needs for this: it can provide an automatic upgrade path.

  Up until now, this issue has been saying we need the media and media_library modules to be enabled. But … we could also just do that conditionally as a first step:

  For Drupal 9|10 sites without media/media_library that switch to CKEditor 5

  Keep the current behavior.

  For Drupal 9|10 sites with media/media_library that switch to CKEditor 5

  Switch to Media automatically!

  This seems like a golden opportunity to at least move a big chunk of Drupal sites in the right direction!?

  Thoughts? 🤓

but … the Standard install profile still has not enabled media by default, let alone media_library 😔😔😔

It makes no sense to block CKEditor 5 becoming stable on something that is A) a separate concern, B) has lingered for many years.

So moved this to "post-stable".

Yay, #3227822: [GHS] Ensure GHS works with our custom plugins, to allow adding additional attributes landed, which was the last remaining item under Ensure that sites can update from using CKE4 to CKE5 safely when using no contributed CKEditor modules! 🥳

6 days ago, in #33, I wrote: But there are more that we created in the past few weeks. (More to follow tomorrow, but here's what I gathered so far.) — well, consider today that "tomorrow" 😅

Roughly 50% of the remaining open issues created since the beginning of 2022 are not stable blocking, and the remaining ~50% are. I added those to the roadmap here — they are:

• Ensure CKE5 functionality matches that of Drupal core's CKE4: #3264775: [drupalMedia] Toolbar should be visible when element inside <drupalMedia> is focused
• Superior configuration UX: #3261943: Confusing behavior after pressing "Apply changes to allowed tags" with invalid value
• Ensure CKE5 equivalent plugins of CKE4 generate/support equivalent markup: #3261599: Use CKEditor 5's native <ol start> support (and also support <ol reversed>)
• Superior configuration UX: #3261585: Remove IE11 warning for CKEditor 5 in Drupal 10, since Drupal 10 does not support IE anyway
• Superior configuration UX: #3260857: Expand SourceEditingRedundantTagsConstraintValidator to also check attributes and attribute values
• Superior configuration UX: #3259795: Generalize textPartLanguage's validation: no configuration allowed unless the plugin's toolbar item is active
• Superior configuration UX: #3259443: Plugin settings do not appear when a configurable plugin is added AFTER removing all buttons

#3260853: [GHS] Partial wildcard attributes (<foo data-*>, <foo *-bar-*>, <foo *-bar>) and attribute values (<h2 id="jump-*">) not yet supported landed!

#3264775: [drupalMedia] Toolbar should be visible when element inside <drupalMedia> is focused landed!

#3264727: [drupalMedia|drupalImage] Allow removing data-align in the UI, and making an image inline landed!

#3260032: CKEditor 5 adds ie11.user.warnings library to every page, triggering a FOUC even for anonymous users landed!

EDIT: and that was the last Performance issue! 🥳 AFAICT this means we now meet the Drupal core "Performance" gate: https://www.drupal.org/about/core/policies/core-change-policies/drupal-c....

#3194084: Support functionality equivalent to ckeditor_stylesheets landed!

#3245950: [upstream] <script> tag support in GHS is fixed thanks to #3261600: Update to CKEditor5 v32.0.0 having landed!

Just realized that #3248430: Improve Drupal.ckeditor5 documentation is in the wrong bucket; it belongs under Documentation gates IMHO.

New Ensure that sites can update from using CKE4 to CKE5 safely when using no contributed CKEditor modules issue: #3268174: Bug in CKE 4 → 5 upgrade path "format" does not always map to "heading", it could map to "codeBlock" too, or both, or neither — discovered in #3263384: Add ckeditor5-code-block package and CodeBlock plugin.

@lauriii discovered a critical bug unfortunately: #3268306: [GHS] Custom/unofficial HTML tags not retained: <drupal-media>, <drupal-entity>, <foobar>.

@lauriii discovered two more bugs: #3268318: [drupalMedia] <a> with GHS allowed attributes downcast wraps data-caption with <a> + #3268311: [upstream] [drupalMedia] GHS-enabled markup in data-caption crashes CKEditor 5.

Just triaged all remaining issues with @lauriii.

We updated a few issues with comments or improved titles.

#3248425: Ensure that all classes and functions in Drupal-specific CKEditor 5 plugins are documented should've been under Documentation gates

And we identified X issues that should no longer be stable blockers:

• #3248432: [drupalImage] Split DrupalImageEditing into multiple plugins
• #3227354: Add support for ckeditor5-autoformat

We didn't go through Superior configuration UX: because we felt it'd be important to have a Product Manager with us to do that.

@lauriii will start working on #3268311: [upstream] [drupalMedia] GHS-enabled markup in data-caption crashes CKEditor 5 now because we identified that as the highest risk/highest uncertainty one that remains.

#3248430: Improve Drupal.ckeditor5 documentation landed!

#3256566: [upstream] <style> tag support in GHS is done thanks to #3269064: Update to CKEditor 5 v33.0.0. #3230230: Enable table captions; override CKE5's default downcast to generate <table><caption></table> instead of <figure><table><figcaption></figure> is now unblocked.

#3268174: Bug in CKE 4 → 5 upgrade path "format" does not always map to "heading", it could map to "codeBlock" too, or both, or neither landed!

#3267721: Add DrupalCI step for ensuring that CKEditor 5 build files are build correctly was missing from the roadmap … but it just landed!

• #3248228: Unable to change selection after linking inline media when manual decorators have been defined landed, which unblocks #3247683: Disable CKEditor 5's automatic link decorators (in Drupal filters should be used instead).
• #3231337: [drupalMedia] Remove manual dataDowncast from DrupalMediaEditing landed.

#3260869: Resolve mismatch between <$block> interpretation by CKEditor 5 and Drupal is finally in!

But … @lauriii identified #3268307: $block wildcard resolves into a superset of the actual $block tags as an additional stable blocker, so that now takes its place. Fortunately it's a lot simpler.

@lauriii found another data loss stable blocker: #3269868: [drupalImage] Some Image attributes are lost in edge cases where image upcasts into inline image.

Landed:

• #3231328: SmartDefaultSettings should select the CKE5 plugin that minimizes creation of HTML restriction supersets → unblocked #3263384: Add ckeditor5-code-block package and CodeBlock plugin
• #3270110: Toolbar config items missing "press arrow to do {x}" instructions for screenreaders
• #3270112: Excessive aria-live announcing from ckeditor5-admin-help-message live region

#3270108: Editor does not load when using Edge + WHCM and #3259443: Plugin settings do not appear when a configurable plugin is added AFTER removing all buttons landed.

Made a mistake in #66.

One question on the upgrade path, apart from ckeditor4, what happens if you try to add editor support to an existing format that doesn't have an editor enabled?

SmartDefaultSettings computes a CKEditor 5 configuration matching the text format's HTML restrictions, to ensure we support a superset. See the filter_only__filter_html test case in \Drupal\Tests\ckeditor5\Kernel\SmartDefaultSettingsTest::provider() for an example.

Also, what happens when you switch formats from a format without an editor enabled, to ckeditor5?

Same thing as happens when switching to CKEditor 4, thanks to #2099741: Protect WYSIWYG Editors from XSS Without Destroying User Data 😊

Well, that became more nuanced in the meantime 😅 See #3239012-8: [11.x] Remove the CKEditor 4 upgrade path, and more importantly, see #3270831: Make the CKEditor 4 → 5 upgrade path work even when the CKEditor 4 module is removed! 🤓 😄

#3263384: Add ckeditor5-code-block package and CodeBlock plugin landed.

#3261585: Remove IE11 warning for CKEditor 5 in Drupal 10, since Drupal 10 does not support IE anyway landed.

#3268860: Elements wrapping <drupal-media> are not retained landed!

@lauriii found another upstream critical data loss bug: #3271418: [upstream] [drupalMedia] Linked media wrapped with <div> doesn't upcast correctly.

#3269868: [drupalImage] Some Image attributes are lost in edge cases where image upcasts into inline image landed!

#3260857: Expand SourceEditingRedundantTagsConstraintValidator to also check attributes and attribute values landed!

#3268307: $block wildcard resolves into a superset of the actual $block tags landed.

#3231336: Simplify HtmlRestrictions and FundamentalCompatibilityConstraintValidator now that "forbidden tags" are deprecated is no longer a stable blocker due to #3272516: Deprecate FilterInterface::getHTMLRestrictions()' forbidden_tags functionality.

#3222757: [drupalImage] Make image alt text required or strongly encouraged landed! The last accessibility stable blocker!

Happy to report that I discovered #3228580: Follow-up for #3222852: additional test coverage for real-time validation race conditions has been irrelevant for many months, ever since #3228477: CKEditor5PluginConfigurableInterface should extend PluginFormInterface and ConfigurableInterface instead of adding ::settingsForm() happened! It just was never a high enough priority to investigate. But with few issues remaining, it made sense today :)

#3230230: Enable table captions; override CKE5's default downcast to generate <table><caption></table> instead of <figure><table><figcaption></figure> is in the wrong bucket.

Same for #3247634: [upstream] [drupalImage] Unlinking linked inline images while GHS is enabled: wrapping <a> is impossible to remove, #3268318: [drupalMedia] <a> with GHS allowed attributes downcast wraps data-caption with <a> and #3268311: [upstream] [drupalMedia] GHS-enabled markup in data-caption crashes CKEditor 5

All four belong in the Ensure that sites can update from using CKE4 to CKE5 safely when using no contributed CKEditor modules bucket.

Moved them.

#3222756: Allow using images from external source is also in the wrong bucket: the markup is supported already (i.e. it is not lost), we're just lacking the UX to create images that are externally hosted ("hotlinked").

(This is a very bad practice, but we should ensure that existing content doesn't break.)

#3261599: Use CKEditor 5's native <ol start> support (and also support <ol reversed>) is also in the wrong bucket: the markup is supported already, and editable already. But instead of requiring users to go to "Source Editing" today (just like in CKEditor 4, actually!), we should allow them to use the native functionality instead.

So, moved to Low-hanging fruit major UX improvements over CKEditor 4.

Finally, #3228691: Restrict allowed additional attributes to prevent self XSS is also in the wrong bucket: this is purely a thing to improve the configuration UX and overall security — you can configure CKEditor 4 to allow self-XSS, but once this lands, you won't be able to anymore. Which means that it'll only be possible to self-XSS if already there are no HTML restrictions, i.e. when using the Full HTML text format.

Therefore, moving to Superior configuration UX.

Consequently, the Ensure CKE5 equivalent plugins of CKE4 generate/support equivalent markup bucket is done, which more closely reflects reality: all of the markup that could be edited with CKE4 can already be edited with CKE5 today! 🤓🥳🚀 ***

*** With the exception of a few upstream critical data loss bugs that only manifest in very specific circumstances, listed in the Ensure that sites can update from using CKE4 to CKE5 safely when using no contributed CKEditor modules bucket.

#3269657: [drupalMedia] The CKEditor 4 → 5 upgrade path for the media_embed filter should not forcefully allow the `data-view-mode` attribute on `<drupal-media>` was split off from #3245720: [drupalMedia] Support choosing a view mode for <drupal-media>, but it's an essential follow-up. So adding to the roadmap :)

#3268983: [regression] FilterHtml throws Unsupported operand types error when * used in tag attribute is a bug introduced by #3228334: Refactor HTMLRestrictionsUtilities to a HtmlRestrictions value object 😬

New stable blockers discovered (so far…) at Drupal Dev Days Ghent 2022:

1. #3273527: Upgrade path never configures the ckeditor5_heading plugin to allow <h1>
2. #3273510: CKEditor 5 crash when multiple alignment buttons are activated due to duplicate configuration
3. #3273312: Upgrading from CKEditor 4 for a text format that has FilterInterface::TYPE_MARKUP_LANGUAGE filters enabled

🥳 Better to know about these now rather than months from now!

• #3273527: Upgrade path never configures the ckeditor5_heading plugin to allow <h1> and #3273312: Upgrading from CKEditor 4 for a text format that has FilterInterface::TYPE_MARKUP_LANGUAGE filters enabled landed during Drupal Dev Days Ghent 2022 last week!
• #3265626: Changes to "Manually editable HTML tags" lost if form is submitted without triggering AJAX landed Saturday.

New stable blockers, both relating to the upgrade path for contrib modules:

• #3238333: Roadmap to CKEditor 5 stable in Drupal 9
• #3273325: CKE5 and contrib: better "next action" description on upgrade path messages

Oops, that first one should have been #3274278: Migrate "codetag" contrib CKEditor 4 plugin to built-in equivalent in core's CKEditor 5 of course.

One more stable blocker discovered: #3274937: Get CKEditor 5 to work in (modal) dialogs.

#3268318: [drupalMedia] <a> with GHS allowed attributes downcast wraps data-caption with <a> is fixed, which is possible now that we've done #3269651: Update Drupal 9.3.x to CKEditor 5 v34.0.0 along with other un-backported issues 👍

#3274651: Impossible to enable <ol type> or <ul type> with GHS: switch to List's successor, DocumentList is another stable blocker that was discovered at DDD: it results in losing the type attribute on either <ol> or <ul>.

#3245720: [drupalMedia] Support choosing a view mode for <drupal-media> just landed, which means #3269657: [drupalMedia] The CKEditor 4 → 5 upgrade path for the media_embed filter should not forcefully allow the `data-view-mode` attribute on `<drupal-media>` is now unblocked!

#3274278: Migrate "codetag" contrib CKEditor 4 plugin to built-in equivalent in core's CKEditor 5 landed!

#3273325: CKE5 and contrib: better "next action" description on upgrade path messages just landed!

#3230230: Enable table captions; override CKE5's default downcast to generate <table><caption></table> instead of <figure><table><figcaption></figure> and #3261943: Confusing behavior after pressing "Apply changes to allowed tags" with invalid value landed!

@bnjmnm just found a new stable-blocking bug: #3238333: Roadmap to CKEditor 5 stable in Drupal 9 👍

Obviously the link in #100 was wrong 🙈 It should've been #3276974: [drupalMedia] Media View Modes don't work if alignment not enabled.

Good news: #3268311: [upstream] [drupalMedia] GHS-enabled markup in data-caption crashes CKEditor 5 has been fixed upstream, and we got the fix thanks to #3274767: Update to CKEditor 5 v34.0.0. We still had that issue to write an explicit test, but per #3268311-14: [upstream] [drupalMedia] GHS-enabled markup in data-caption crashes CKEditor 5, that is not possible. One less stable blocker! 🥳

#3231334: Global attributes (<* lang> and <* dir="ltr rtl">): validation + support (fix data loss) landed :)

#3248425: Ensure that all classes and functions in Drupal-specific CKEditor 5 plugins are documented just landed!

#3229078: Unit tests for all @CKEditor5Plugin plugin classes and #3261599: Use CKEditor 5's native <ol start> support (and also support <ol reversed>) landed 👍

And non-stable blocker #3277405: Update @ckeditor/ckeditor5-list to v34.0.1 also landed, which means that stable blocker #3274651: Impossible to enable <ol type> or <ul type> with GHS: switch to List's successor, DocumentList is now unblocked 🥳

I did another round of ckeditor5.module issue queue triaging. Results:

• New stable blocker: #3272516: Deprecate FilterInterface::getHTMLRestrictions()' forbidden_tags functionality — deprecation in filter module which has allowed us to make #3231336: Simplify HtmlRestrictions and FundamentalCompatibilityConstraintValidator now that "forbidden tags" are deprecated not a stable blocker.
• New stable blocker: #3273983: Do not assume that plugin supporting <tag attr> also supports <tag> in SourceEditingRedundantTags and upgrade path — this is the last issue raised at DDD Ghent 2022 that hasn't been thoroughly followed up on so far.
• Added #3263668: Re-enable inline form errors in assessActiveTextEditorAfterBuild function to post-stable roadmap, specifically under Upstream Drupal improvements that would simplify or improve CKEditor 5, which is blocked on a Vertical Tabs bugfix.
• Added #3269101: [PP-1] Ensure enabled CKEditor 5 plugins remain available by calculating corresponding dependencies to post-stable roadmap, under the same section, but this one is blocked on Text Editor module gaining proper support for config dependencies.
• Added #3248432: [drupalImage] Split DrupalImageEditing into multiple plugins, #3273746: Move media-embed-error class styling from core themes to CKEditor 5, #3275237: Don't convert, instead use response.entity_type in DrupalImageUploadEditing to post-stable roadmap's Maintainability section.
• Added #3274635: [upstream] Use CKEditor 5's native <ol type> and <ul type> UX to post-stable roadmap's Low-hanging fruit major UX improvements over CKEditor 4 section.

#3276974: [drupalMedia] Media View Modes don't work if alignment not enabled landed!

#3228691: Restrict allowed additional attributes to prevent self XSS landed 🚀

Moved it to the wrong place 🙈

#3272516: Deprecate FilterInterface::getHTMLRestrictions()' forbidden_tags functionality landed!

#3269657: [drupalMedia] The CKEditor 4 → 5 upgrade path for the media_embed filter should not forcefully allow the `data-view-mode` attribute on `<drupal-media>` landed 👍

#3259593: Alignment being available as separate buttons AND in dropdown is confusing landed, which means #3273510: CKEditor 5 crash when multiple alignment buttons are activated due to duplicate configuration no longer occurs! Marking it as fixed :)

#3277438: Update to CKEditor 5 v34.1.0 allowed us to mark 2 stable blockers as done! 🥳

1. #3271418: [upstream] [drupalMedia] Linked media wrapped with <div> doesn't upcast correctly
2. #3247634: [upstream] [drupalImage] Unlinking linked inline images while GHS is enabled: wrapping <a> is impossible to remove

🥳

10 stable blockers remain, of which 2 are blocked on upstream.

#3274651: Impossible to enable <ol type> or <ul type> with GHS: switch to List's successor, DocumentList landed!

#3276217: [drupalMedia] add tests to confirm GHS attributes are retained in linked media landed.

5 new stable blockers, all for accessibility. Thanks @bnjmnm for triaging https://github.com/ckeditor/ckeditor5/labels/domain%3Aaccessibility:

1. #3283800: [upstream] CKE5 dropdowns keyboard support
2. #3283801: [upstream] CKE5 dropdown focus handling is not fully accessible
3. #3283802: Update CKEditor 5 to 35.3.2 to fix voice control/IME on some platforms
4. #3283803: [upstream] CKE5 toggleable toolbar items not enough contrast
5. #3283804: [upstream] CKE5 dropdown screenreader support

#3247683: Disable CKEditor 5's automatic link decorators (in Drupal filters should be used instead) and #3273983: Do not assume that plugin supporting <tag attr> also supports <tag> in SourceEditingRedundantTags and upgrade path landed! That means #3222797: Upgrade path from CKEditor 4's StylesCombo to CKEditor 5's Style is now unblocked 👍

#3274937: Get CKEditor 5 to work in (modal) dialogs is in!

#3290810: Remove updates added prior to 9.4.0 (9.4.4 for ckeditor) and add 9.4.0 database dumps landed.

Added #3294908: Configuration overlaps between Styles and other CKE5 plugins.

#3294908: Configuration overlaps between Styles and other CKE5 plugins landed!

#3268306: [GHS] Custom/unofficial HTML tags not retained: <drupal-media>, <drupal-entity>, <foobar> landed 👍

#3306216: Contrast perception issues with icons including low-opacity fills landed!

#3222756: Allow using images from external source landed ✔️

Fixed thanks to #3306153: Update CKEditor 5 to 35.1.0 landing:

• #3283800: [upstream] CKE5 dropdowns keyboard support
• #3283801: [upstream] CKE5 dropdown focus handling is not fully accessible
• #3283803: [upstream] CKE5 toggleable toolbar items not enough contrast
• #3283804: [upstream] CKE5 dropdown screenreader support

That only leaves #3283802: Update CKEditor 5 to 35.3.2 to fix voice control/IME on some platforms, but per @xjm in #138, that need not block marking CKEditor 5 as stable in #3307186: Mark CKEditor 5 stable!

CKEditor 5 is now stable!

See #3307186-32: Mark CKEditor 5 stable.

🚀

P.S.: @lauriii even wrote a haiku for the occasion:

I write, erase, rewrite
Erase again, and then
CKEditor 5 is stable

👏

Final update: #3283802: Update CKEditor 5 to 35.3.2 to fix voice control/IME on some platforms landed a week ago! 😊