Belighted WTF : What's new in Rails 4 ?

Overview of changes, new features, deprecations in the upcoming new version of Ruby on Rails.

Transcript

1. Weekly Technical Forum What's new in Rails 4 ?
2. Rails 4 at a glance.
3. Table of Contents 1. Turbolinks 2. Queue API 3. Strong parameters 4. Cache digests 5. Routing concerns 6. ActiveRecord::Relation 7. Deprecations 8. Further reading
4. Turbolinks
5. Turbolinks Intended as a replacement for PJAX, focused on simplicity. • Uses pushState to reload the whole body. • Like PJAX, also replaces the <title> tag. • Default in Rails 4, enabled for every link. • Already available in 3.2.8 : https://github.com/rails/turbolinks
6. Turbolinks : benchmark Steve Klabnik wrote a sample app to demonstrate speed gains with heavy assets : https://github.com/steveklabnik/turbolinks_test This uses both the JS/CSS files from Basecamp Next.
7. Turbolinks : in detail Steve Klabnik's video. Let's also do a live benchmark.
8. Turbolinks : gotchas As it is enabled by default, you can opt-out on a per-link basis : It does not trigger the document.ready event in JS, so we'd have to also bind relevant code to page.change, like so : $(function() { initPage(); }); $(window).bind('page.change', function() { initPage(); }); link_to "Awesome home page", root_path, data: { no-turbolinks: true }
9. Queue API
10. Intends to unify all background job providers (delayed_job, resque, ...) under a common, easily-accessible API. Queue API
11. Queue API : code example It just requires an object that responds to #run. Class UserMailJob < Struct.new(:user_id) def run user = User.find(user_id) UserMailer.welcome(user).deliver end end # In users_controller.rb Rails.queue.push UserMailJob.new(@user.id)
12. Strong parameters
13. Strong parameters Moves the concern of attribute access entirely to the controller. Also works for nested resources. class UsersController def create User.create(user_params) end private def user_params params.require(:user). permit(:email, :name) end end
14. Available already in 3.2.8 : https://github.com/rails/strong_parameters Strong parameters
15. Cache digests
16. Cache digests In this situation, you'd normally have to manually expire all dependencies if you changed anything in _comment.html.erb Well, no more !
17. Cache digests • Appends a MD5 digest to a cached template and all its dependencies. • Works implicitly for most rendering cases. • Can also be called explicitly with a comment. <%# Template Dependency: users/comment %> • Available already in 3.2.8 : https://github.com/rails/cache_digests
18. Routing concerns
19. Routing concerns Reusable routes across several resources.
20. ActiveRecord::Relation
21. ActiveRecord::Relation • Relation.first / Relation.last Always ordered by id. • Relation.all Always returns a ActiveRecord::Relation object. • Relation.none Returns a ActiveRecord::NullRelation, for those cases you would return an empty array.
22. ActiveRecord::Relation : bang! Rails 4 adds several bang methods that actually mutate the relation on the fly.
23. Deprecations
24. Deprecations • ActiveRecord::Base.scoped • Dynamic finder methods (find_all_by_...) • Hash-based finders (User.find(:all)) • Scopes are no longer eager-evaluated, need a lambda. • AR::SessionStore, ActiveRessource extracted as gems. • Rails 2-style plugins are completely removed (finally!)
25. Rails Edge guides (generated from master) http://edgeguides.rubyonrails.org/4_0_release_notes.html BostonRB slides on Rails 4. https://speakerdeck.com/u/bostonrb/p/what-to-expect-in-rails-4-dot-0 Video on Rails Queues by Caike Souza http://www.codeschool.com/code_tv/rails-4-queues A Fresh cup : weekly follow-up of the changes in Rails master. http://afreshcup.com/ Further reading
26. HAMMERTIME. STOP