The image must extend $block

[Reinmar]

As explained in https://github.com/ckeditor/ckeditor5-engine/issues/532#issuecomment-280919795.

It's a part of bigger refactoring which we need to make.

[scofalik]

I wonder whether we should re-think what kind of abstract definitions we have in schema. Maybe having $block is just incorrect?

[Reinmar]

That's still open for me too. But I don't think that "block" is that bad. Image is a block element after all. It's just not a text container.

[Reinmar]

Handling block images correctly will require https://github.com/ckeditor/ckeditor5-engine/issues/894.

[Reinmar]

Once we'll make image a block, we also need to check if it's correctly handled in some merging scenarios on Backspace. E.g. ckeditor/ckeditor5-engine#907 (comment)

[Reinmar]

We made caption inheriting from blocks in https://github.com/ckeditor/ckeditor5-image/pull/95/files which introduced https://github.com/ckeditor/ckeditor5-block-quote/issues/10 ;<.

[Reinmar]

This was fixed once we refactored the schema. The $block element was detached from the isBlock property. Now, the image can have isBlock, be "allowed where $block is", but it's also isObject so it's filtered out properly by e.g. the list feature.