I use the Drupal 8 Book module for books where each chapter has a different author.
The Book Navigation block uses book-tree.html.twig (core/modules/book/templates) to generate a book tree showing chapter titles. I want to show author names also.
I can subclass and edit book-tree.html.twig, but I don't know how to get the author name passed in so I can use it. How do I go about this? Only the title, the url, and some flags are passed in now.
As an alternative, I can get the id for each chapter node from its url as a string. Can I use this id to load the chapter node from within the twig template? If so, I can get the author name from the node directly.