Topics Covered

• Upgrade walkthrough and checklists
• Removal of Rails 2 style plugins
• Deprecation of Rails 2 finder syntax (e.g., find(:all))
• Changes to routing: applications that use match may be affected
• Deprecation of certain dynamic finders (e.g., find_all_by_...)
• Deprecation of eager-evaluated scopes
• Changes to ActiveRecord::Relation: #all, #includes, and #order
• Removal of whiny nils
• Security improvements when using validates_format_of
• Extraction of the ActiveRecord Session Store
• Extraction of action caching and page caching
• Extraction of activeresource
• Image assets in lib/ and vendor/ are no longer automatically precompiled
• Changes to cross-site request forgery protection with AJAX (remote) forms

• Turbolinks introduction and usage
• Thread-safe by default: how to upgrade and what to look out for
• Improvements to ActiveRecord associations
• Introduction of model and controller concerns: app/models/concerns and app/controllers/concerns
• Introduction of strong_parameters as an alternative to attr_accessible and attr_protected
• Support for the PATCH verb
• Routing concerns
• ActionController::Live for live streaming
• Russian doll caching
• Declarative ETags for caching
• Encrypted cookies
• Binaries are generated in bin/ and checked into source control (bin/rails and bin/rake)
• New default test directory structure (test/models, test/controllers, etc...)

Updates

Upgrading to Rails 4 covers the major deprecations and new features in Rails 4.0.0.rc1. You will also receive updates (via email) as Rails 4.0.0 final nears.

Guarantee

If you purchase Upgrading to Rails 4 and are not satisfied, email me and I will issue you a refund.

rails4_upgrade gem

Some chapters in the book use the rails4_upgrade gem, a free/open-source project I started to make certain elements of the upgrade process easier. Check it out and let me know what you think.

Reviewers

Thanks to these folks who are looking over the book's content for technical accuracy and overall flow:

• Steve Klabnik
• Caius Durling
• Ashish Dixit
• Ernie Miller
• Darcy Laycock
• Sean Marcia
• Giles Bowkett

Recent Updates

• April 29, 2013: Updates gem versions for Rails 4.0.0.rc1.
• April 26, 2013: How to install new binaries in bin/, Rails 4 no longer uses the :assets group in Gemfile, encrypted cookies have changed slightly since 4.0.0.beta1, dalli is required to use memcached.
• March 21, 2013: XML parsing has been extracted to a gem, rails test command, strong_parameters can raise an exception in development mode, validates_confirmation_of adds error messages to the _confirmation field.

Who is the author?

I'm Andy Lindeman. My day job has me work with Rails on a daily basis. I also help to maintain rspec—a popular testing framework—and its Rails' helpers, rspec-rails.

I gave a widely viewed presentation for the Atlanta Ruby Users Group entitled Rails 4 Whirlwind Tour.

I'd love to hear from you. You can email me, follow me on Twitter, and watch me on GitHub.