Edit existing category

[ebdavison]

I have been following along with this excellent walk-through and an impressed with the work. Only one thing lacking that I have really been struggling with and that is how to edit an existing Category.

I am sure that the CategoryForm can be re-used but cannot figure out the proper URL nor can I figure out yet how to pass which category to edit to the form/view. I have tried UpdateView class but it complains about an unknown parameter when I pass either a "pk" or "category_id" ...

Can you address how to edit an existing Category?