This book is for programmers looking to build and deploy web-based applications. This includes application programmers who are new to Rails (and perhaps even new to Ruby) as well as those who are familiar with the basics but want a more in-depth understanding of Rails.
We presume some familiarity with HTML, Cascading Style Sheets (CSS), and JavaScript—in other words, the ability to view source on web pages. You needn’t be an expert on these subjects; the most you’ll be expected to do is copy and paste material from the book, all of which can be downloaded.
The focus of this book is on the features and choices made by the Rails core team. More specifically, this book is for users of the Rails framework—people who tend to be more concerned about what Rails does, as opposed to how it does it or how to change Rails to suit their needs. Examples of topics not covered in this book include the following:
Introduced in Rails 4, Turbolinks is a way to load pages more quickly by just loading markup.[4] If you want to know more about how Rails makes your pages load faster, follow that link. But should you instead be content with the knowledge that Rails makes pages load fast and not need to know more, that’s OK too.
Rails itself is highly hackable and extensible, but this book doesn’t cover the concept of how to create your own Rails engine.[5] If that topic is of interest to you, we highly recommend Crafting Rails 4 Applications [Val13] as a follow-on to this book.
The Rails team has chosen not to include plenty of features—such as user authentication—in the Rails framework itself. That doesn’t mean that these features aren’t important, but it generally does mean that no single solution is the obvious default for Rails users.