What's New in Rails 4.2

A brief overview of new features in Ruby on Rails 4.2

Presented at Austin on Rails on October 28, 2014

Transcript

1. What's New In Rails 4.2 Anthony Lewis
2. @AnthonyLewis Best known for my hit single “Candy Rain”
3. @AnthonyLewis Also, wrote a book…
4. Rails 4.2 • Active Job • Action Mailer • Global ID • Adequate Record • Web Console • Other Changes • Installation • Release Notes
5. Active Job • Framework for background processing using Resque, Delayed Job, Sidekiq, etc. • Switch between background runners without having to rewrite jobs • If no adapter is specified, jobs run immediately
6. Configuration • Add your preferred background processing library to your application’s Gemfile: • Update Rails configuration: gem 'sidekiq' config.active_job.queue_adapter = :sidekiq
7. Creating Jobs • Use the Rails generator to create a new job: $ bin/rail g job process_video create app/jobs/process_video_job.rb
8. Job Source • The newly created job: class ProcessVideoJob < ActiveJob::Base queue_as :default def perform(*args) # Do something later end end
9. Enqueue Job • Enqueue with or without a time: # Run next ProcessVideo.perform_later(@video) # Run tomorrow ProcessVideo.set(wait: 1.day) .perform_later(@video)
10. Error Handling • Catch exceptions with a block: class ProcessVideoJob < ActiveJob::Base ... rescue_from(Exception) do |e| # do something with exception end end
11. Action Mailer • ActionMailer now uses ActiveJob to send email • Call deliver_now to send a message inline # Send inline UserMailer.success_email(@user) .deliver_now
12. Action Mailer • Call deliver_later to enqueue delivery • Accepts :wait, :wait_until, and :queue options # Enqueue and send later UserMailer.success_email(@user) .deliver_later
13. Global ID • A unique identifier for a model instance • ActiveJob uses Global ID to automatically serialize and deserialize objects irb> video.to_global_id.to_s => "gid://appname/Video/1"
14. Adequate Record • Optimizations to Active Record that make the find, find_by_*, and find_by methods up to 2x faster • Caches the static parts of the SQL query User.find(1) # Caches the static part: # SELECT * FROM users WHERE id = ? User.find(2) # Uses the cache, executes faster
15. Web Console • Debugging tool for your Rails app • Automatically opens a Rails console on exceptions • Can also be opened with the console view helper <%= console %>
17. Other Changes • Previously deprecated functionality has been removed • Check for deprecation warnings before updating • The respond_with / class-level respond_to methods have been moved to the responders gem • The default host for rails server is now localhost instead of 0.0.0.0 • If you dev in a virtual machine this will bite you
18. Other Changes • The default log level for production is now :debug, just like development and test • The HTML sanitizer has been replaced with a new version. • Some sanitized output might change • Foreign key support (finally) • And more…
19. Release Notes • The work-in-progress release notes are online: http://edgeguides.rubyonrails.org/4_2_release_notes.html
20. Installation # In your terminal: $ gem install rails --pre # In your Gemfile: gem 'rails', '~> 4.2.0.beta2'
21. Questions?
22. Thank You!