Ruby on Rails is unquestionably Ruby’s killer app. It can take a lot of credit for lifting Ruby from obscurity outside its native Japan. No other programming language can boast a simple web application framework that also has almost all of that language’s developer mindshare.1 This chapter demonstrates the principles underlying basic Rails usage (in recipes like Recipe 16.6), gives Rails implementations of common web application patterns (Recipes 16.4 and 16.8) and shows how to use standard Ruby tools from within Rails (Recipes 16.22 and 16.23).
Despite its quality and popularity, Rails does not bring anything new to web development. Its foundations are in standard programming patterns like ActiveRecord and Model-View-Controller. It reuses many preexisting Ruby libraries (like Rake and ERb). The power of Rails is in combining these standard techniques with a ruthless dedication to automating menial tasks, and to asserting resonable default behaviors.
If Rails has a secret, it’s the power of naming conventions. The vast majority of web applications are CRUD applications; that is, they create, read, update, and delete information from a database. In these types of applications, Rails shines. You start with a database schema and with almost no code, but Rails ties together many pieces with naming conventions and shortcuts. This lets you put meat on your application very quickly.
Because so many settings and names can be sensibly derived ...