Improvements to the cell tags plugin

[choldgraf]

This is assuming that #7407 gets merged, which adds core jlab support for cell tags.

Two features that I think would improve the cell tags functionality:

The ability to quickly scan which tags are in each cell

It would be useful to give people visual cues of what tags are attached to a cell without that cell being selected. In the old notebook tag system, you'd see a little word for each tag within the cell header, which made it easy to quickly skim them and see what tags were where. E.g.:

In JupyterLab, you need to make a few UI clicks to see which cells have which tags. It makes this a big clunkier, and impossible to quickly skim the distribution of tags in a notebook:

The ability for users to pre-define some tags

Another useful item would be if there were a way for extension authors to define a list of tags that would be available to users. This would allow users to more quickly enable / disable functionality using tags for a particular use-case.

An example of this is Jupyter Book - currently, users can show / hide elements using hide_input, hide_output, etc tags. However, knowing the full list of possible tags requires people going through the documentation reference. Moreover, there are annoying little things like remembering it's hide_input and not hide_inputs. These add cognitive load to users.

If it were possible for Jupyter Book to say "if the jupyter-book lab extension is installed, then make this subset of tags pre-listed as options", then it could remove this ambiguity without requiring a whole new UI section that's just dedicated to Jupyter Book tags.

[fcollonval]

FYI I released an extension to address this as well as some action buttons: https://github.com/fcollonval/jlab-enhanced-cell-toolbar

[choldgraf]

That is so cool!

[jasongrout]

CC @pya