Technology books are more like milk than wine. They don’t get better with age. Brad Ediger’s Advanced Rails is fairly well written and provides lots of details, but much of the information is outdated. Ruby on Rails has changed. The plugin ecosystem of Ruby gems has changed. Even the underlying Ruby language has changed.
Ediger used detailed examples to explain advanced Ruby on Rails concepts. Oh, did I mention they were detailed? Yeah, lots of details. If I had just bought the book in 2008 and was building a Rails web applications, then those examples may have been super helpful. But I read this in 2014 and did not find the information helpful. Advanced Rails covers a good list of topics including security, RESTful web services, performance optimization, and internationalization, but it isn’t worth slogging through pages of coding details for projects that have probably changed significantly or are no longer influential in the ecosystem.
I would not recommend reading Advanced Rails. It has curdled.