CKEditor 5 compatibility

Problem/Motivation

Drupal 10 will be delivered with CKEditor 5 (since Drupal 9.3.x, we can enable CKEditor 5 module and set it as a text editor).

In order to make this plugin available for Drupal 10, we should have a branch compliant with Drupal 9 & 10. and rewrite the plugin as it is actually not compatible with CKEditor 5.

Proposed resolution

• On the branch 8.x-2.x create the new Plugin for CKEditor 5
• On the same branch (8.x-2.x) we must have an Upgrade path from CKEditor 4 to CKEditor 5
• Then once everything works with tests for CKE5 & CKE4, we will be able to create another fork branch 3.0.x that only support CKE5 & D10.

Remaining tasks

• ✅ Having a working CKE5 Image Balloon
• ✅ Having a working Upgrade Path from CKE4 to CKE5
• ✅ Having tests for both CK4 & CK5
• List the project under https://www.drupal.org/docs/core-modules-and-themes/core-modules/ckedito... →

User interface changes

The Editor Advanced Button on the CKE5 Image Balloon (the EAI button is the 3 dotted icon).

The Editor Advanced Balloon with all attributes visible.