The focus on "AJAX contact forms, AJAX file uploads, Avatar Cropping" in the blurb is odd. It sounds like you'll be getting a rundown on some handrolled jQuery stuff.
Personally I can see the benefit of banging out a form in jQuery instead of having to research and integrate another system, but something about the chapter summaries seem strange. It sounds like it's more about building custom front-end components than integrating different libraries (which is what I expected from the title).
In the prerequisites to the book it clearly states that novice developers will have a hard time unless they have some backend experience.
Seeing the integration with a back end (any backend tbh) is better.