Sanity on Rails — How to write maintainable Rails applications in 2017

Rails is not your application! Don’t overcomplicate your development life by trying to make everything fit within its MVC structure. A framework provides tools and abstractions, use them to build your business logic, don’t force your business logic to fit into them.

1. Sanity on Rails Michael Kohl Deccan RubyConf 2017
2. • Michael Kohl (@citizen428) • CTO @ Lockstep Labs • Based in Bangkok, Thailand • Ruby developer since ~2004 • Former mentor at RubyLearning Deccan RubyConf 2017 locksteplabs.com Yours truly
3. Deccan RubyConf 2017 locksteplabs.com The problem
4. Deccan RubyConf 2017 locksteplabs.com The problem • Recurring problems • Dependencies • Framework entanglement • Implicit code • Good news: easily avoidable
5. Deccan RubyConf 2017 locksteplabs.com Dependencies
6. Deccan RubyConf 2017 locksteplabs.com Dependencies • Bootstrap the app faster • Prevent “not invented here syndrome” • Get peer reviewed • Easily get outdated • Memory footprint & startup times • Have more dependencies
7. Deccan RubyConf 2017 locksteplabs.com Dependencies • Be selective about dependencies • Look for actively maintained gems • Use gems for common tasks • Prefer developers with vested interest
8. Deccan RubyConf 2017 locksteplabs.com Dependencies
9. Deccan RubyConf 2017 locksteplabs.com Dependencies
10. Deccan RubyConf 2017 locksteplabs.com Framework entanglement
11. "A basic conceptional structure (as of ideas)" – Merriam Webster "A basic structure underlying a system, concept, or text." – Oxford English dictionary Deccan RubyConf 2017 locksteplabs.com Frameworks
12. Deccan RubyConf 2017 locksteplabs.com Frameworks - Controllers • Abstracting HTTP communication • Authentication • Authorization • Sessions / cookies • Param validation / transformation • Redirection / rendering
13. Deccan RubyConf 2017 locksteplabs.com Frameworks - Controllers # Actions resources :actions, only: [:index] namespace :actions do resource :enqueue_cvs, only: [:create] resource :import_cvs, only: [:create] resource :generate_suggestions, only: [:create] resource :logs, only: [:destroy] end # Users resources :users, except: [:new, :edit, :show] namespace :users do resources :filters, only: [:create] resources :passwords, only: [:create, :edit, :update] end
14. Deccan RubyConf 2017 locksteplabs.com Frameworks - Models • Wrapper around datastore • ActiveRecord configuration • Associations • Validations • Finders / scopes • Simple accessors / mutation methods
15. Deccan RubyConf 2017 locksteplabs.com Frameworks - Models • Extract POROs • Various extraction patterns • Service objects • Form objects • Query objects • many more • Use namespacing
16. Deccan RubyConf 2017 locksteplabs.com Frameworks - Models ! tree app/services/cv app/services/cv "## file_mover.rb "## importer.rb "## parser.rb "## repository.rb "## suggestion_handler.rb $## viewer.rb
17. Deccan RubyConf 2017 locksteplabs.com Frameworks - Models require_dependency 'cv' class Cv # Class for importing CV files into ElasticSearch in a standardized way. class Importer attr_accessor :file_name, :content, :md5sum, :file_type, :attributes, :parse def self.import(file_name, content, attr = {}) new(file_name, content, attr).import end def initialize(file_name, content, attr = {}) self.file_name = File.basename(file_name) … parse_attributes(attr) end def import add_to_es extract_plaintext parse_cv if parse end
18. Deccan RubyConf 2017 locksteplabs.com Frameworks - Models Credit: Code Climate
19. Deccan RubyConf 2017 locksteplabs.com Frameworks - Models class AbandonedTrialQuery def initialize(relation = Account.scoped) @relation = relation end def find_each(&block) @relation. where(plan: nil, invites_count: 0). find_each(&block) end end Credit: Code Climate
20. Deccan RubyConf 2017 locksteplabs.com Frameworks - Views • Response generation • Should be mostly logic free • Rails conflates view model & template • Helpers become dumping grounds
21. Deccan RubyConf 2017 locksteplabs.com Frameworks - Views class UserView < ApplicationView include ActionView::Helpers::TagHelper forward :first_name, :last_name def formatted_full_name content_tag :strong, "#{first_name} #{last_name}" end end
22. Deccan RubyConf 2017 locksteplabs.com Implicit code
23. Deccan RubyConf 2017 locksteplabs.com Implicit code • “Convention over configuration” • Magic: • AR configuration • Instance variables in views • Implicit code: • AR callbacks • before_action/after_action
24. Deccan RubyConf 2017 locksteplabs.com Implicit code • Hard for newcomers to understand • Hard to follow code flow • Easy, not simple • Doesn’t apply in all cases
25. Deccan RubyConf 2017 locksteplabs.com Implicit code • Be more explicit! • Reading is more important than writing! • POROs to encapsulate processes • Don’t try to be too clever!
26. • Be selective when adding gems • Build business logic on top of what Rails provides, don’t mix it with framework code • Explicit is often better than implicit • There are no silver bullets, all software development involves tradeoffs. Deccan RubyConf 2017 locksteplabs.com Summary
27. • How DHH Organizes His Rails Controllers
 http://jeromedalbert.com/how-dhh-organizes- his-rails-controllers/ • 7 Patterns to Refactor Fat ActiveRecord Models
 http://blog.codeclimate.com/blog/2012/10/17/7- ways-to-decompose-fat-activerecord-models/ • Objects on Rails
 http://objectsonrails.com Deccan RubyConf 2017 locksteplabs.com Resources
28. Deccan RubyConf 2017 locksteplabs.com Thank you!