[upstream] [GHS] colgroup and col elements are removed from markup when included in "Manually editable HTML tags"

I am assuming this will need to be either a bug or feature request upstream in CKEditor - but reporting here first to get feedback / ideas.

+1 😅 Glad you thought of this already! 🙏

In CKEditor5 the colgroup and col elements are removed from the markup when editing - even when added to "Manually editable HTML tags" or when using Full HTML format.

This sounds like a bug in CKEditor 5's Table plugin's integration with their GeneralHtmlSupport plugin.

Please repeat this bug report upstream, including your sample markup to reproduce it. 🙏

In short - I believe col and colgroup elements should be supported without requiring the TableColumnResize plugin / allowing full HTML. The practicalities of that approach I am unsure of.

It is not possible to support these additional elements automatically when the Table plugin/UI is enabled, because:

		{
			"name": "Table column resize",
			"className": "TableColumnResize",
			"description": "Adds support for table column resize, which allows to set the width of each column in a table using a resize handle.",
			"docs": "features/tables/tables-resize.html",
			"path": "src/tablecolumnresize.js",
			"requires": [
				"Table"
			],
			"htmlOutput": [
				{
					"elements": "colgroup"
				},
				{
					"elements": "col",
					"styles": "width"
				}
			]

— https://github.com/ckeditor/ckeditor5/blob/v39.0.0/packages/ckeditor5-ta...

👆 only that additional CKEditor 5 plugin is able to create those elements. But you're right that it should be possible to support them manually through the use of GHS (which in Drupal indeed corresponds to configuring them as ).

Thanks Wim - appreciate the direction of where to look. I've opened upstream bug https://github.com/ckeditor/ckeditor5/issues/15368

Note that actually just a few days ago I finished 📌 [Style] Warn the user about styles for unsupported elements Needs work , which would warn you immediately that this is not yet supported. That should mitigate the frustration, but it won't unblock you. So keeping this issue around … waiting for an upstream fix :)

Possibly because ✨ Add table.TableColumnResize for formats with arbitrary HTML supported RTBC isn't committed yet, I seem to be able to define these elements in a custom plugin without anything complaining that table resize already defines them.

It might break when that issue lands but for now I'm working around using https://www.drupal.org/project/ckeditor5_colgroup → which I've published if anybody else is in the same situation and needs a short term fix.

Hopefully this gets traction upstream and I can abandoned that work around

📌 [Style] Warn the user about styles for unsupported elements Needs work just made this easier to discover 👍