Rails - The Dark Side-2016

Rails is awesome! This is what everyone says. On this talk we will try to check all point of views about the framework. Rails can have some dark sides, horribles, actually. I will let you know what are those aspects/sides and how to avoid them. Many of the truths that we cling to depend on our point of view. Do not turn to the dark side!

Transcript

1. Rails: The Dark Side Franzé Jr.
2. @franzejr
4. Disclaimer “Many of the truths that we cling to depend on our point of view”
5. Different Point of View
6. JS.ERB
7. JS.ERB Controller def my_controller_method ... respond_to do |format| format.html format.js { render template: 'create.js.erb' } end end
8. JS.ERB create.js.erb $("#new_donation").modal("hide"); $("#new_donation").remove(); <%if @donation.state == "paid"%> var content = "<%=escape_javascript(render '/donations/approved_donation')%>"; <%else%> var content = "<%=escape_javascript(render '/donations/refused_donation')%>"; <%end%> ! $(".money #campaign").prepend(content).hide().slideDown() ! $(".money .box.donations").block() ! var donations_html = "<%=escape_javascript(render '/donations/donation', donation: @donation)%>"; $(".money .box.donations .no_donations").remove()/ $(".money .box.donations .transactions-list").append(donations_html); $(".money .box.donations").unblock()
9. JS.ERB create.js.erb $("#new_donation").modal("hide"); $("#new_donation").remove(); <%if @donation.state == "paid"%> var content = "<%=escape_javascript(render '/donations/approved_donation')%>"; <%else%> var content = "<%=escape_javascript(render '/donations/refused_donation')%>"; <%end%> ! $(".money #campaign").prepend(content).hide().slideDown() ! $(".money .box.donations").block() ! var donations_html = "<%=escape_javascript(render '/donations/donation', donation: @donation)%>"; $(".money .box.donations .no_donations").remove()/ $(".money .box.donations .transactions-list").append(donations_html); $(".money .box.donations").unblock()
10. JS.ERB • Client side ? Server side? • It doesn’t look good - mix of JS + ( HTML ) + Ruby ! var poll_stats_html = "<%=escape_javascript(render '/money_polls/money_use_option_stats') %>"; <% if params[:partial_id].present? %> var apend_to = "#feed_<%= params[:partial_id] %>_money_poll_<%=@money_poll.id%>"; <% else %> var apend_to = "#money_poll_<%=@money_poll.id%>"; <% end %> $(poll_stats_html).hide().appendTo(apend_to).fadeIn("slow");
11. JS.ERB Performance
12. JS.ERB Lack of flexibility
13. JS.ERB Complexity Logic in your javascript views to update the page var div = document.createElement("div"); var activities = $(div).html("<%=j render(@feed)%>"); TweenLite.to($(div).find(".activity"), 0, {opacity:0}); $('.ban2').append(activities); TweenMax.staggerTo($(div).find(".activity"), 0.6, {opacity:1}, 0.1); ! <% if @feed.next_page %> $('.pagination').replaceWith('<%= j will_paginate(@feed) %>'); <% else %> $('.pagination').remove(); $('.loadmore').remove(); <% end %>
14. JS.ERB - Potential Solutions A LOT
15. “You cannot escape your destiny. You must face Darth Vader again.”
16. Compatibility / Versions
17. Compatibility / Versions Rails has serious problems with update gems and the Ruby version itself ! “The problem with Rails is not the pace of change so much as the wild changes of direction it takes, sometimes introducing serious performance degradations into official releases. Sometimes it's hard to see a guiding core philosophy other than the fact they want to be on the shiny edge”
18. Learning Curve
19. Learning Curve ❏ ERB Syntax! ❏ HAML/ SLIM! ❏ Puma/Thin! ❏ Capistrano! ❏ RSPEC/Minitest! ❏ Cucumber ❏ Ruby! ❏ Ruby Philosophy! ❏ Active Record! ❏ Gem Management / Bundler! ❏ Routing in Rails
20. And six months later...
22. “Patience you must have my young Padawan.”
23. Scaffolding
24. Scaffolding // Not a good idea ! ! “Rails is awesome because you can do a simple app in one day and it can help you in the creation”
25. Scaffolding // Not a good idea • Inexperienced developers can put scaffold code in production • Don’t have notion about its features • Every project is different and you cannot think it will do all the same. • DO NOT use it professionally.
26. Helpers
27. Helpers Basically:! ! " Improve data visualisation! ! " Help rendering some UI component
28. Helpers Mix HTML/Ruby code module DeviseHelper def devise_error_messages! return "" if resource.errors.empty? ! messages = resource.errors.full_messages.map { |msg| content_tag(:li, msg) }.join sentence = I18n.t("errors.messages.not_saved", :count => resource.errors.count, :resource => resource.class.model_name.human.downcase) ! html = <<-HTML <div id="error_explanation" class="alert alert-danger fade in"> <h4>#{sentence}</h4> <ul>#{messages}</ul> </div> HTML ! html.html_safe end end
29. Helpers Mix HTML/Ruby code module DeviseHelper def devise_error_messages! return "" if resource.errors.empty? ! messages = resource.errors.full_messages.map { |msg| content_tag(:li, msg) }.join sentence = I18n.t("errors.messages.not_saved", :count => resource.errors.count, :resource => resource.class.model_name.human.downcase) ! html = <<-HTML <div id="error_explanation" class="alert alert-danger fade in"> <h4>#{sentence}</h4> <ul>#{messages}</ul> </div> HTML ! html.html_safe end end
30. Let’s define a simple helper...
31. And now we have: " Nebulous namespace spread across all controllers/views
32. Not a good idea.
33. Helpers - Potential Solutions Draper adds an object-oriented layer of presentation logic to your Rails application. Without Draper, this functionality might have been tangled up in procedural helpers or adding bulk to your models. With Draper decorators, you can wrap your models with presentation-related logic to organise - and test - this layer of your app much more effectively.
34. Helpers - Potential Solutions https://github.com/drapergem/draper
35. Helpers - Potential Solutions Cells allow you to encapsulate parts of your UI into components into view models. View models, or cells, are simple ruby classes that can render templates.
36. Helpers - Potential Solutions
37. Concerns
38. Concerns ! ! ! "Concerns are also a helpful way of extracting a slice of model that doesn’t seem part of its essence (what is and isn’t in the essence of a model is a fuzzy line and a longer discussion) without going full-bore Single Responsibility Principle and running the risk of ballooning your object inventory." - DHH Why we should use concerns?
39. Is it not a good idea?
40. It depends
41. Concerns Why this can be Bad? Even there are a lot of posts saying Concerns is good idea...
42. Concerns
43. Concerns
45. Concerns • Syntactic Sugar - for include/extend // Add complexity to Ruby's mixins • Add Dependency and Hide complexity • Harder to navigate in the codebase
46. It provides value for your system?
47. Do not use it blindly.
48. Solutions?
49. SINGLE RESPONSIBILITY PRINCIPLE
50. A class should have only one reason to change Robert C. Martin
52. ActiveInteraction manages application-specific business logic. It's an implementation of the command pattern in Ruby.
53. - app/ - controllers/ - accounts_controller.rb - interactions/ - accounts/ - create_account.rb - destroy_account.rb - find_account.rb - list_accounts.rb - update_account.rb - models/ - account.rb - views/ - account/ - edit.html.erb - index.html.erb - new.html.erb - show.html.erb
54. # GET /accounts def index @accounts = ListAccounts.run! end class ListAccounts < ActiveInteraction::Base def execute Account.not_deleted.order(last_name: :asc, first_name: :asc) end end Controller Interaction
55. # GET /accounts/:id def show @account = find_account! end ! private ! def find_account! outcome = FindAccount.run(params) ! if outcome.valid? outcome.result else fail ActiveRecord::RecordNotFound, outcome.errors.full_messages.to_sentence end end Controller
56. class FindAccount < ActiveInteraction::Base integer :id ! def execute account = Account.not_deleted.find_by_id(id) ! if account account else errors.add(:id, 'does not exist') end end end Interaction
57. “The dark side clouds everything. Impossible to see the future is”
58. Thanks!
59. References • https://signalvnoise.com/posts/3372-put-chubby-models-on-a-diet-with-concerns • https://signalvnoise.com/posts/1108-what-belongs-in-a-helper-method • http://www.imdb.com/title/tt0086190/quotes • http://nicksda.apotomo.de/2010/11/lets-write-a-reusable-sidebar-component-in-rails-3/ • https://github.com/apotonick/cells • https://github.com/drapergem/draper • http://blog.codeclimate.com/blog/2012/10/17/7-ways-to-decompose-fat-activerecord-models/ • http://brewhouse.io/blog/2014/04/30/gourmet-service-objects.html • https://github.com/orgsync/active_interaction • https://en.wikipedia.org/wiki/Single_responsibility_principle#cite_note-1