Consider making the insert/append/remove view/model API protected

[Reinmar]

Currently I can't think of a case in which you should use methods like Node.remove() or Element.appendChildren(). In all cases which I know you either use deltas (when operating on the model) or model/view writer (when converting).

So, we can make this API protected. In other words, view and model nodes should be immutable, unless you're using the writer or deltas.

Also, we should consider simplifying the writer (at least the model one), because it requires working with ranges which is a pain. I'm constantly changing:

el.appendChildren( foo );

into:

modelWriter.insert( ModelRange.createOn( el ), foo );

Related issue: https://github.com/ckeditor/ckeditor5-engine/issues/737.

[Reinmar]

Once we'll get rid of the public API from nodes, we can perhaps reintroduce it using the writers. Although, perhaps keeping writer and deltas as separate tools is better, because then you'll need to consciously choose which to use.

[pjasiun]

Agree that there is no more good reason to keep them public. One can say that they create the API of this class but it the API which should not be used publically.

The reason why the writer is not used there is because of the circular dependencies. In both view and model, positions, ranges and writer create a layer on top of nodes. It solved a lot of circular dependencies, but it also means that nodes can't use writers, it needs to be included separately.

In general, levels of the model API is the part which should be reviewed before the release. I remember we had a global ticket about this somewhere.

[pjasiun]

It's almost exactly a year since the last comment here and the code is finally ready to keep everything as one API (new writer API). Note that it's not only nodes API what need to be changed to protected, but also selection and markers (and maybe something else).