1.1. Rails Strengths

As you go through this book, you'll learn how Rails can thrive without all of the extensive libraries required by other languages. Ruby's flexibility lets you extend your applications in ways that might have been previously unavailable to you. You'll be able to use a Rails feature called scaffolding to put database-backed user interfaces in front of your customers quickly. Then, as you improve your code, the scaffolding melts away. You'll be able to build database-backed model objects with just a couple of lines of code, and Rails will fill in the tedious details.

The most common programming problem in today's typical development project involves building a web-based user interface to manage a relational database. For that class of problems, Rails is much more productive than any other web development framework either of us has ever used. The strengths aren't limited to any single groundbreaking invention; rather, Rails is packed with features that make you more productive, with many of the following features building on one other:

Metaprogramming

Metaprogramming techniques use programs to write programs. Other frameworks use extensive code generation, which gives users a one-time productivity boost but little else, and customization scripts let the user add customization code in only a small number of carefully selected points. Metaprogramming replaces these two primitive techniques and eliminates their disadvantages. Ruby is one of the best languages for metaprogramming, and Rails uses this capability well.^[]

^[] Rails also uses code generation but relies much more on metaprogramming for the heavy lifting.

Active Record

Rails introduces the Active Record framework, which saves objects to the database. Based on a design pattern cataloged by Martin Fowler, the Rails version of Active Record discovers the columns in a database schema and automatically attaches them to your domain objects using metaprogramming. This approach to wrapping database tables is simple, elegant, and powerful.

Convention over configuration

Most web development frameworks for .NET or Java force you to write pages of configuration code. If you follow suggested naming conventions, Rails doesn't need much configuration. In fact, you can often cut your total configuration code by a factor of five or more over similar Java frameworks just by following common conventions.

Scaffolding

You often create temporary code in the early stages of development to help get an application up quickly and see how major components work together. Rails automatically creates much of the scaffolding you'll need.

Built-in testing

Rails creates simple automated tests you can then extend. Rails also provides supporting code called harnesses and fixtures that make test cases easier to write and run. Ruby can then execute all your automated tests with the rake utility.

Three environments: development, testing, and production

Rails gives you three default environments: development, testing, and production. Each behaves slightly differently, making your entire software development cycle easier. For example, Rails creates a fresh copy of the Test database for each test run.

There's much more, too, including Ajax for rich user interfaces, partial views and helpers for reusing view code, built-in caching, a mailing framework, and web services. We can't get to all of Rails' features in this book; however, we will let you know where to get more information. But the best way to appreciate Rails is to see it in action, so let's get to it.