Block comments should not be owned by the icon in a rendered workspace

Problem statement

On a rendered workspace the icon for opening the comment also owns the text for that comment. This means the block model depends on the rendered icon for information about the comment text (and position). This information should be independent of the icon so that it isn’t lost when loaded/saved in a headless workspace.

Expected Behavior

• Comment data is preserved in headless workspaces.
• There should not be any special cases for serializing comments.

Actual Behavior

• Only the text is preserved in a headless workspace.
• We have to special case delete events to avoid losing the comment when its icon is destroyed.

Steps to Reproduce

See discussion in #1960

Stack Traces

Replace with error stack trace.

Operating System and Browser

Additional Information

[RoboErikG]

So it looks like block_svg is essentially doing that. If the comment text is set to null it deletes the icon and any string object (including empty string) creates the icon if it doesn’t already exist.

Regarding events, it looks like the event setting the comment text to ‘’ is a side effect and the addition/removal of the comment isn’t actually captured in events right now (if you add a comment then remove it without adding any text you won’t see any events). I think adding a comment should fire an event setting the event text to ‘’ and removing a comment should fire an event setting it to null.

Whether we serialize empty comments is a separate question. It looks like we currently don’t, which I’m fine with.

[samelhusseini]

Fixed by #2923