Was hoping to see fireworks and i read bubble gums. It's ok but is for beginners, nothing fancy nor complex. Using php for serving the pages and node.js as back-end.
Example are shown trough the stock market, live update from values and symbols.
Nicest part, the notes for improvements.
Didn't learn a lot, just basics. Probably the interest chapter are the last 2, authentication and fall back ways from SSE to normal polling with ajax. Nothing that I've didn't heard of.
I won't recommend it.