Building_Rails_with_Trailblazer_slides.pdf

RubyConf TW 2019

Transcript

1. Building Rails with Trailblazer, The Good, Bad and Ugly 開拓拓者們建立鐵道的辛酸⾎血淚淚史
2. Why This Talk? Share some experience Collect insights from people here Make some friends Free conference tickets
3. @wenchuan_lin
4. 1 Experience with Ruby?
 3 Form Object?
 Service Object? 2 Experience with Rails? 4 Trailblazer(TRB)?
5. Controller def create run Song::Create do |result| redirect_to songs_path(result["model"]) end render :new end def create authorize! :create, Song @song = Song.new(params[:song]) if @song.save current_user.increment_song_counter redirect_to @song else render :new end end Rails Rails With TRB
6. Model class Song < ActiveRecord::Base has_many :authors end class Song < ActiveRecord::Base has_many :authors validates :name, :author, presence: true after_save :notify_author end Rails Rails With TRB
7. TRB Operation class Song::Create < Trailblazer::Operation step Model( Song, :new ) step Policy::Pundit( Policy, :create? ) step Contract::Build( constant: Song::Create ) step Contract::Validate() step Contract::Persist() fail Notifier::DBError step :update_song_count! step :notify_author def update_song_count!(options, current_user:, **) current_user.increment_song_counter end def notify_author!(options, **) #… end end class Song::Create < Reform::Form property :name validate :name, presence: true end Reform
9. The Advanced Business Logic Framework It extends the basic MVC pattern with new abstractions.
10. Then Why Trailblazer?
11. Story • Huge Web Form • Complicated Associations between Models • Increasing Requirements and Features
12. The Decision ✅ Great Fit to Our Scenario ✅ Integration with Rails (Validation / I18n) ✅ Online Documentation / Book ✅ Incrementally Adoptable
13. 2016 Q3 - Kickoff / Initial commit 2017 Q1 - Only 3 Operations Created... 2017 Q2 - 2 Core Business Concepts Migrated 2017 Q4 - EmailMessage 2018 Q2 - OnlineAppForm Now... TimeLine
14. 7xx Classes, 5x Concepts Business / Utils / Migration….
15. Obstacles
16. ::call !"" ::build_operation # !"" #initialize # # !"" #setup! # # # !"" #assign_params! # # # # # !"" #params! # # # !"" #setup_params! # # # !"" #build_model! # # # # !"" #assign_model! # # # # # !"" #model! # # # # !"" #setup_model! # !"" #run # # !"" #process Callstack in Operation Too many….
17. DSL in Trailblazer-Rails Form / Present / Call / Run…..
18. You need more than Book / Documentation But Sometimes the source code is difficult to trace - Trailblazer - Trailblazer-operation - Trailblazer-rails - Trailblazer-loader - Reform / Reform-Rails - Disposable / Twin - Cell - ……
19. Getter, Setter Reform #to_nested_hash #deserialize! ActiveModel #attributes #assign_attributes
20. *main process of Reform object
 **alias method for #valid?
 #valid? 
 Method (A) #validate Method (B) #validate_with Method(C) Reform ✅ * ✅ ❎ ActiveModel ✅ ** ✅ ✅ Validation Layer
21. Populate In Reform songs: [ {name: "Midnight Rendezvous"}, {name: "Information Error"} ] class Song < ActiveRecord::Base belongs_to :album end class Album < ActiveRecord::Base has_many :songs end class AlbumForm < Reform::Form collection :songs, populate_if_empty: Song do property :name end end
22. Miscellaneous I18n Scope / Simple Form / Form builder / Trailblazer Loader
23. def update fail 'Invalid submit value' if !params[:complete].present? && !params[:update].present? obj = resource_instance obj.assign_attributes(items_completion_params) if params[:update] ? obj.save : obj.complete_items respond_to do |format| format.html { redirect_to obj, notice: "#{params[:commit]} successfully completed." } format.json { render json: {status: :ok} } end else if params[:update] respond_to do |format| format.html { redirect_to obj, alert: obj.errors.full_messages.join(', ') } format.json { render json: {status: :bad_request, msg: 'Failed to update remark'} } end else flash.now[:alert] = 'Failed to complete' obj.items.select(&:_complete).each { |i| i.status = Dealing::STATUS_DEALING } render :edit end end end Revisit, Refactor, Rewrite def update result = Dealing::Save.call(params) if result.success? # ... elsif result['complete.failure?'] flash.now[:alert] = 'Failed to complete' render :edit else # ... end end class Dealing::Save < Trailblazer::Operation step Model( Song, :find ) step Nested { :build! } step Contract::Build( constant: Dealing::Update ) step Contract::Validate() step Contract::Persist() #=> save failure :error! def build!(options, params:, **) if params[:complete].present? Dealing::Complete elsif params[:update].present? self.class else fail 'Invalid submit value' end end end class Dealing::Complete < Trailblazer::Operation step Contract::Build( constant: Dealing::Complete ) step Contract::Validate() step Contract::Persist() #=> complete_items failure :error! failure :revert_status! def revert_status!(options, **) #... end end Save Complete
24. What do we get from Trailblazer?
25. Cost • Another framework / DSL to learn • Sometimes it is not so friendly to Rails • The part of document is incomplete • Debug is harder than before
26. The Benefits
27. Easy to Test Manual / Automation
28. Business Process Driven Process Builder / Policy / Concept Folder
29. Maintainability Separation of Concerns
30. Resilient Team Respond to Change / Build Convention
31. That’s IT? Tips of Technology Adoption
32. Goal Oriented Set a Goal in Early Stage, and Retrospective
33. 1 Training / Team Support Discussion / Code Review / Pair Programming
34. 34 Be a Evangelist 守、破、離 / Keep improving
35. More than a Tool / Framework Level Up the Mindset
36. Conclusion
37. No Conclusion Just some friendly advice …..
38. Separate Business⚡ Persistence Layers
39. Step-Wise, Keep Pushing
41. Ruby, Rails, Trailblazer
42. Thank you