Ruby on Rails 2.3: What's New, Release History & Support Lifecycle

What Is New in Ruby on Rails 2.3

How does the Rack integration in Rails 2.3 affect my existing application?

Rails 2.3 runs the entire stack on Rack, which means every request passes through a configurable middleware chain before reaching your controllers.

In practice this gives you three immediate benefits:

• You can swap the built-in WEBrick server for any Rack-compatible server (Thin, Puma, Unicorn) simply by running script/server with a config.ru file.
• The new rake middleware task lets you inspect ordering, add custom middleware, or remove the default ActionController::Lock if you manage concurrency elsewhere.
• Session handling is now lazy-loaded and lives in Rack, so sessions are only touched when you actually read or write session in your controller.

Watch out for code that directly accessed CgiRequest or relied on CGI-specific environment variables - those classes have been removed.

# Example: inserting a custom middleware
# config/initializers/custom_middleware.rb
Rails.application.config.middleware.insert_before ActionDispatch::Static, "MyAuthMiddleware"

What are the most important Active Record enhancements in Rails 2.3?

Rails 2.3 adds nested attributes, nested transactions, dynamic/default scopes, and batch find methods to make complex data workflows easier.

• Nested attributes let you save a parent and its children in one call: accepts_nested_attributes_for :author, :pages.
• Nested transactions use savepoints so you can roll back an inner block without aborting the outer one, e.g. User.transaction { ... User.transaction(:requires_new => true) { ... raise ActiveRecord::Rollback } }.
• Dynamic scopes generate methods on the fly (Order.scoped_by_customer_id(12)) and default_scope applies a base ordering to every query.
• Batch processing with find_in_batches and find_each reduces memory pressure when iterating over thousands of rows.

This matters if your app imports large CSV files or needs atomic updates across several associated models.

How have rendering and routing changed in Rails 2.3?

Rails 2.3 simplifies rendering by inferring the type of template from the string you pass to render, and it streamlines routing by dropping the old formatted_ helpers.

Examples:

# Old style
render :template => 'posts/show'
# New style
render 'posts/show'

Routing now accepts :format as a regular option, cutting route-generation time by roughly 50% and saving up to 100 MB of memory in large apps. You can also split routes across multiple files with RouteSet#add_configuration_file, which is handy for engines.

What should I know about session handling and middleware in Rails 2.3?

Sessions are now lazy-loaded and live in the Rack layer, meaning they are only instantiated when you reference session in a controller.

• Switching the session store is still done via ActionController::Base.session_store = :active_record_store, but the underlying classes have been renamed (e.g., ActionController::Session::CookieStore).
• The mutex that once wrapped the whole request is now the ActionController::Lock middleware, giving you finer control over concurrency.
• Use rake middleware to verify that ActionDispatch::Session::CookieStore (or your chosen store) appears in the stack.

Most teams will see no functional change, but if you previously disabled sessions globally you can now simply avoid touching session and the overhead disappears.