(Alt.) Refactor BoundColumn attributes to allow override of class names. #349

[graup]

Related issue: #349
Original PR: #367

So now I added Table.get_column_class_names which gets the original set of class names (parsed from column attributes) as well as the bound column to replicate the old behavior but allow to override it.

This might still need a bit more documentation, I think.

[jieter]

shouldn't this be get_td_class_names or just get_td_class?

[jieter]

Thanks for working on this secont option, I think I like this one better, API is simpler.

Not totally sure about:

• the name of get_column_class_names,
• in the case of the <th>, a note about the adding addition of ordering/descending/ascending to the class might be in place.
• while writing the previous point, I noticed we have a different but similar way in which we allow customisation of the classes for ordering. Why not use something like that to tackle this problem? (Not very well thought through yet).
• As for documenting it, I think the get_colum_class_names docstr should mention it is intended to be overridden to allow customisation.
• Some others which I commented on inline.

[graup]

I fixed the things you mentioned and added more documentation.

I agree with your third point, it is still a bit weird to have a completely different API for this. I was also thinking about how we could get this into the attributes, but the only option I saw would be to allow passing a function (or lambda) into that, which is also a bit messy.

[graup]

At least with this version the (eventual) removal of the name class and migration path is very clear. We just have to remove the line classes_set.add(bound_column.name) and tell people to override the function to add it back.

[jieter]

Decided to merge, thanks @graup!

[jieter]

I just did a pre-release of 2.0.0 with version 2.0.0a0. Please help by testing and report any issues.