Anything written after 1.3 is almost completely applicable today. The auth generator is just a new feature. Learning how the pieces work from the book is still

Anything written after 1.3 is almost completely applicable today. The auth generator is just a new feature. Learning how the pieces work from the book is still worthwhile. My advice if you want to avoid confusion as you're learning is to just use the same version of Phoenix the book does! (1.4 in this case) After you go through it, you can follow the official upgrade guides in just a few minutes.