ckeditor5 - custom container element - recursion error on paste - ckeditor5

Question

I'm trying to create a CKEditor5 custom element plugin - mainly for custom format/styles -- nested divs etc. Managed to be able to inject/format the elements, and I can type in them. But if I try to copy and paste text into a custom element I get a too much recursion error.
MyWidget plugin:
export default class MyWidgetPlugin extends Plugin {
init() {
const editor = this.editor;
editor.model.schema.register('my-widget', {
inheritAllFrom: '$root',
isLimit: true,
});
editor.conversion.elementToElement({ model: 'my-widget', view: 'my-widget' });
editor.commands.add('myWidget', new MyWidgetCommand(editor));
}
}
MyWidget command:
class MyWidgetCommand extends Command {
execute() {
const editor = this.editor;
const block = first(this.editor.model.document.selection.getSelectedBlocks());
this.editor.model.change(writer => {
const myWidget = writer.createElement('my-widget')
writer.insert ( myWidget, block, 'after');
writer.appendElement( 'paragraph', myWidget );
});
}
}
Inserting a widget injects this into the editor:
<my-widget>
<p></p>
</my-widget>
And I can type fine, but I can't paste. I'm guessing I got the schema wrong... have played around with quite a few different options.. but to no avail.

Answer 1

I didn't check it but I think that the issue is here:
editor.model.schema.register('my-widget', {
inheritAllFrom: '$root',
isLimit: true,
});
This schema rule says that <my-widget> will allow e.g. a <paragraph> inside it. But it doesn't say anything about where <my-widget> may be used. That's because $root is not allowed in any other element (cause it's a root :)).
I think that the following should work fine:
editor.model.schema.register('my-widget', {
inheritAllFrom: '$root',
allowIn: '$root',
isLimit: true,
});
Alternatively, a more generic solution should work too:
editor.model.schema.register('my-widget', {
inheritAllFrom: '$root',
allowWhere: '$block',
isLimit: true,
});
Still, the editor should not crash with an infinite loop, so I reported https://github.com/ckeditor/ckeditor5-engine/issues/1441.