Introduce a way to check if changes were introduced by typing

[scofalik]

I think it would be useful to have a way to check if given changes were done through typing. I see it as a method on Typing or InputCommand instance.

This could be solved in one of two ways:

1. Add special batch type (yeah, we made precedence with undo :P).
2. Store all InputCommand batches in some kind of a WeakSet.

Then, we could use it like this:

modelDocument.on( 'change', ( evt, batch ) => {
    if ( typingPlugin.isTyping( batch ) ) {
        // ...
    }
} );

modelDocument.registerPostFixer( writer => {
    if ( typingPlugin.isTyping( writer.batch ) ) {
        // ...
    }
} );

When this is done, we should fix changes introduced by this PR: https://github.com/ckeditor/ckeditor5-typing/pull/213/files

[Reinmar]

Sounds really interesting. 👍

[jodator]

I'm also in favor of such change. There are many cases in which we need such check and some standardized way for this would be awesome.

I like the typing batch type (and possibly create undo batch types also).

[Reinmar]

When this is done, we should fix changes introduced by this PR: https://github.com/ckeditor/ckeditor5-typing/pull/213/files

If this PR needs to add some API that we'd be removing after closing this ticket, I'd do that right now.

[Reinmar]

I like the typing batch type (and possibly create undo batch types also).

I don't know the situation and I can't tell if this makes sense in a long run – whether we'll not need dozens of types and/or those types will become unreliable for some reason (by getting weaker meaning or something). Once we'll start introducing them there will be no way back.

2. Store all InputCommand batches in some kind of a WeakSet.

So, unless you're really sure about the new types, I'd go for local changes, like the proposed here.

[jodator]

Quick questions about API:

1. Shouldn't we check isInput() vs isTyping() - technically we would like to check user input as in Input plugin.
2. Resolving the isInput() vs isTyping() will resolve where the method lands. For me it looks like inputPlugin.isInput( batch ) - other wise as proposed by @scofalik.
3. Should we expose the InputCommand.batches? I'd say this is protected but OTOH the InputCommand.buffer is exposed.

[Reinmar]

Ad 1. Typing = input + delete. So we can even have multiple methods for that in multiple places.

Ad 3. What would be the purpose of exposing it?

[jodator]

Ad 3. What would be the purpose of exposing it?

None probably. I'd leave that as private.

[scofalik]

Probably not worth exposing right now. I use input buffer batches in track changes (and AFAIR they are used somewhere else too) but that's the "current batch" and this is an important property. Old batches, stored in a WeakMap are probably not useful.