CKEditor removes empty html5 anchors without name attribute

[Henning]

Since the name attribute is obsolete for a elements in html, we made a plugin variant that creates anchors with id attribute only.

However, the anchor elements with just an id attribute are removed by CKEditor automatically.

From ​https://dev.ckeditor.com/ticket/10325 I do understand that you have to remove anchor elements that cannot be edited. But anchor elements having just an id (and no name) attribute are html5, and can be edited at least by our plugin variant.

I don't find a configuration of allowedContent or so to let CKEditor preserve <a id="x"></a>.

From the CKEditor source code, I see that you remove as follows:

• In core\htmldataprocessor.js

// Remove empty link but not empty anchor. (#3829)
  a: function( element ) {
  if ( !( element.children.length || element.attributes.name || element.attributes[ 'data-cke-saved-name' ] ) )

• In function validateElement

case 'a':
  // Code borrowed from htmlDataProcessor, so ACF does the same clean up.
  if ( !( element.children.length || element.attributes.name ) )

My suggestion is allowing to somewhere configure the attributes (other than name) which, if set, preserve empty a elements...

[Piotrek Koszuliński]

I agree. The core should not make a decision about such thing itself or it should be configurable. I would keep empty anchors with id or name and base the removal on ACF's settings. For instance, currently the anchor features allows this:

allowedContent: 'a[!name,id]',

It means that even when we remove that code from HTMLDP and filter.js that anchor will be removed because name is required. But it's ok, because the anchor feature does not recognise such anchors so they are not transformed into fake objects and cannot be edited (this is a thing for a separate ticket if someone misses it). But the point is that we'll unblock other developers who will be able now to use empty anchors without names.

[Henning]

Hi Reinmar,

thank you for scheduling this issue. So we can look forward to remove my rather ugly workaround (temporarily add names to the anchors when editing the text in CKEditor).

Best, Henning

[Olek Nowodziński]

It looks like it needs Reinmar's attention because we're hitting a bus factor wall.

Different approaches in ​branch:t/13516 and ​branch:t/13516-research.

[Olek Nowodziński]

Replying to Reinmar: So it's bigger that expected?

[Piotrek Koszuliński]

No, it isn't. I just won't be able to properly review it in 4.5.2.

[Piotrek Koszuliński]

I pushed ​branch:t/13516b. As you can see it was quite easy, nothing philosophical.

[Szymon Kupś]

Merged changes into master with ​git:1f1a9b3.