Simplifying Controllers - Confoo 2015

simplifying controllers gmalette ! "

true story

Simplicity is prerequisite for reliability Edsger W. Dijkstra “

setting expectations

class PostsController < ApplicationController def new @post = Post.new respond_with
@post end def create @post = Post.create(params[:post].permit(:title, :body)) respond_with @post end def show @post = Post.find(params[:id]) respond_with @post end def index @posts = Post.all respond_with @posts end end

@post end def create @post = Post.create(params[:post].permit(:title, :body)) redirect_to @post end def show @post = Post.find(params[:id]) respond_with @post end def index @posts = Post.all respond_with @posts end end

@post end def create @post = Post.create(params[:post].permit(:title, :body)) respond_with @post end def show @post = Post.find(params[:id]) respond_with @post end def index @posts = Post.all respond_with @posts end end

abstractions

abstractions is preserving information that is relevant in a given
context, and forgetting information that is irrelevant in that context John V Guttag “

African Sunset by ShaunLeeSamson / CC BY-ND 3.0

#33CCCC

def github github_login = env["omniauth.auth"].extra.raw_info.login github_token = env["omniauth.auth"].credentials.token github_user =
User.where(:github_login => github_login).first if github_user.nil? && github_org_id = Errbit::Config.github_org_id client = Octokit::Client.new(access_token: github_token) org_ids = client.organizations.map { |org| org.id.to_s } if org_ids.include?(github_org_id) github_user = User.create( name: env["omniauth.auth"].extra.raw_info.name, email: env["omniauth.auth"].extra.raw_info.email ) end end if current_user if github_user && github_user != current_user flash[:error] = "User already registered with GitHub login '#{github_login}'!" else update_user_with_github_attributes(current_user, github_login, github_token) flash[:success] = "Successfully linked GitHub account!" end redirect_to user_path(current_user) elsif github_user update_user_with_github_attributes(github_user, github_login, github_token) flash[:success] = I18n.t "devise.omniauth_callbacks.success", :kind => "GitHub" sign_in_and_redirect github_user, :event => :authentication else flash[:error] = "There are no authorized users with GitHub login '#{github_login}'." redirect_to new_user_session_path end end

def bulk_update @issues.sort! @copy = params[:copy].present? attributes = parse_params_for_bulk_issue_attributes(params) unsaved_issues
= [] saved_issues = [] if @copy && params[:copy_subtasks].present? @issues.reject! {|issue| @issues.detect {|other| issue.is_descendant_of?(other)}} end @issues.each do |orig_issue| orig_issue.reload if @copy issue = orig_issue.copy({}, :attachments => params[:copy_attachments].present?, :subtasks => params[:copy_subtasks].present?, :link => link_copy?(params[:link_copy]) ) else issue = orig_issue end journal = issue.init_journal(User.current, params[:notes]) issue.safe_attributes = attributes call_hook(:controller_issues_bulk_edit_before_save, { :params => params, :issue => issue }) if issue.save saved_issues << issue else unsaved_issues << orig_issue end end if unsaved_issues.empty? flash[:notice] = l(:notice_successful_update) unless saved_issues.empty? if params[:follow] if @issues.size == 1 && saved_issues.size == 1 redirect_to issue_path(saved_issues.first) elsif saved_issues.map(&:project).uniq.size == 1 redirect_to project_issues_path(saved_issues.map(&:project).first) end else redirect_back_or_default _project_issues_path(@project) end else @saved_issues = @issues @unsaved_issues = unsaved_issues @issues = Issue.visible.where(:id => @unsaved_issues.map(&:id)).to_a bulk_edit render :action => 'bulk_edit' end end

params USS Bowﬁn - Dials, Valves and Knobs by Jacopo
Werther / CC BY 2.0

exit branches Exit to I-20, Downtown Atlanta, Georgia by Ken
Lund / CC BY-SA 2.0

render

redirect_to

rescue_from

telling stories

Emilie

Emilie love chocolate

def emilie_eats_chocolate end

def emilie_eats_chocolate return eat_nothing unless parents_agree? end

def emilie_eats_chocolate return eat_nothing unless parents_agree? go_to_grocery end

def emilie_eats_chocolate return eat_nothing unless parents_agree? go_to_grocery if grocery_is_closed? redirect_to
convenience_store end end

convenience_store else grab_chocolate go_in_line end end

convenience_store else grab_chocolate go_in_line take_out_wallet count_money end end

convenience_store else grab_chocolate go_in_line take_out_wallet count_money if enough_money? hand_money receive_change end end

convenience_store else grab_chocolate go_in_line take_out_wallet count_money if enough_money? hand_money receive_change go_back_home eat_chocolate end end

convenience_store else grab_chocolate go_in_line take_out_wallet count_money if enough_money? hand_money receive_change go_back_home eat_chocolate else go_back_home eat_fruits_instead end end end

who does that?

Macro Raspas de Chocolate by Thavlosk / CC BY-SA 3.0
focus

def emilie_eats_chocolate go_to_grocery grab_chocolate pay go_back_home eat_chocolate end

easy stuff

before_action

in the wild

module Spree class CheckoutController < Spree::StoreController before_action :load_order_with_lock before_action :ensure_valid_state_lock_version,
only: [:update] before_action :set_state_if_present before_action :ensure_order_not_completed before_action :ensure_checkout_allowed before_action :ensure_sufficient_stock_lines before_action :ensure_valid_state before_action :associate_user before_action :check_authorization before_action :apply_coupon_code

awesome!

module Spree class CheckoutController < Spree::StoreController before_action :load_order_with_lock before_action :ensure_valid_state_lock_version,
only: [:update] before_action :set_state_if_present before_action :ensure_order_not_completed before_action :ensure_checkout_allowed before_action :ensure_sufficient_stock_lines before_action :ensure_valid_state before_action :associate_user before_action :check_authorization before_action :apply_coupon_code

module Spree class StoreController < Spree::BaseController include Spree::Core::ControllerHelpers::Order skip_before_action :set_current_order,
only: :cart_link

class Spree::BaseController < ApplicationController include Spree::Core::ControllerHelpers::Auth include Spree::Core::ControllerHelpers::RespondWith include Spree::Core::ControllerHelpers::Common
include Spree::Core::ControllerHelpers::Search include Spree::Core::ControllerHelpers::Store include Spree::Core::ControllerHelpers::StrongParameters

module Spree::Core::ControllerHelpers::Auth included do before_action :set_guest_token end end

before_action :filter_user, only: [:update, :create], if: :user_logged_in?

class UsersController < ApplicationController skip_before_filter :authorize_mini_profiler, only: [:avatar] skip_before_filter :check_xhr,
only: [:show, :password_reset, :update, :account_created, :activate_account, :perform_account_activation, :authorize_email, :user_preferences_redirect, :avatar, :my_redirect] before_filter :ensure_logged_in, only: [:username, :update, :change_email, :user_preferences_redirect, :upload_user_image, :pick_avatar, :destroy_user_image, :destroy, :check_emails] before_filter :respond_to_suspicious_request, only: [:create] skip_before_filter :verify_authenticity_token, only: [:create] skip_before_filter :redirect_to_login_if_required, only: [:check_username, :create, :get_honeypot_value, :account_created, :activate_account, :perform_account_activation, :send_activation_email, :authorize_email, :password_reset]

rescue_from

def show @post = Post.find(params[:id]) rescue ActiveRecord::RecordNotFound render_404 end

def show @post = Post.find(params[:id]) end rescue_from ActiveRecord::RecordNotFound do render_404
end

service objects

@copy = params[:copy].present? attributes = parse_params_for_bulk_issue_attributes(params) unsaved_issues = [] saved_issues
= [] if @copy && params[:copy_subtasks].present? @issues.reject! {|issue| @issues.detect {|other| issue.is_descendant_of?(other)}} end @issues.each do |orig_issue| orig_issue.reload if @copy issue = orig_issue.copy({}, :attachments => params[:copy_attachments].present?, :subtasks => params[:copy_subtasks].present?, :link => link_copy?(params[:link_copy]) ) else issue = orig_issue end journal = issue.init_journal(User.current, params[:notes]) issue.safe_attributes = attributes call_hook(:controller_issues_bulk_edit_before_save, { :params => params, :issue => issue }) if issue.save saved_issues << issue else unsaved_issues << orig_issue end end

@issues = issues @copy = params[:copy].present? @attributes = parse_params_for_bulk_issue_attributes(params) @unsaved_issues
= [] @saved_issues = [] if @copy && params[:copy_subtasks].present? @issues.reject! do |issue| @issues.detect {|other| issue.is_descendant_of?(other)} end end

@issues = issues @copy = params[:copy].present? @attributes = attributes @unsaved_issues
= [] @saved_issues = [] if @copy && params[:copy_subtasks].present? @issues.reject! do |issue| @issues.detect {|other| issue.is_descendant_of?(other)} end end

class BulkIssuesUpdater attr_reader :issues, :copy, :attributes, :unsaved_issues, :saved_issues def initialize(issues,
attributes, params) @issues = issues @copy = params[:copy].present? @attributes = attributes @unsaved_issues = [] @saved_issues = [] if @copy && params[:copy_subtasks].present? @issues.reject! do |issue| @issues.detect {|other| issue.is_descendant_of?(other)} end end end end

@copy = params[:copy].present? attributes = parse_params_for_bulk_issue_attributes(params) unsaved_issues = [] saved_issues
= [] if @copy && params[:copy_subtasks].present? @issues.reject! {|issue| @issues.detect {|other| issue.is_descendant_of?(other)}} end @issues.each do |orig_issue| orig_issue.reload if @copy issue = orig_issue.copy({}, :attachments => params[:copy_attachments].present?, :subtasks => params[:copy_subtasks].present?, :link => link_copy?(params[:link_copy]) ) else issue = orig_issue end journal = issue.init_journal(User.current, params[:notes]) issue.safe_attributes = attributes call_hook(:controller_issues_bulk_edit_before_save, { :params => params, :issue => issue }) if issue.save saved_issues << issue else unsaved_issues << orig_issue end end

@issues.each do |orig_issue| orig_issue.reload if @copy issue = orig_issue.copy({}, :attachments
=> params[:copy_attachments].present?, :subtasks => params[:copy_subtasks].present?, :link => link_copy?(params[:link_copy]) ) else issue = orig_issue end journal = issue.init_journal(User.current, params[:notes]) issue.safe_attributes = attributes call_hook(:controller_issues_bulk_edit_before_save, { stuff }) if issue.save saved_issues << issue else unsaved_issues << orig_issue end end

orig_issue.reload if @copy issue = orig_issue.copy({}, :attachments => params[:copy_attachments].present?, :subtasks
=> params[:copy_subtasks].present?, :link => link_copy?(params[:link_copy]) ) else issue = orig_issue end journal = issue.init_journal(User.current, params[:notes]) issue.safe_attributes = attributes

def update_issue(orig_issue) orig_issue.reload if @copy issue = orig_issue.copy({}, :attachments =>
params[:copy_attachments].present?, :subtasks => params[:copy_subtasks].present?, :link => link_copy?(params[:link_copy]) ) else issue = orig_issue end journal = issue.init_journal(User.current, params[:notes]) issue.safe_attributes = attributes issue end

@issues.each do |orig_issue| orig_issue.reload if @copy issue = orig_issue.copy({}, :attachments
=> params[:copy_attachments].present?, :subtasks => params[:copy_subtasks].present?, :link => link_copy?(params[:link_copy]) ) else issue = orig_issue end journal = issue.init_journal(User.current, params[:notes]) issue.safe_attributes = attributes call_hook(:controller_issues_bulk_edit_before_save, { stuff }) if issue.save saved_issues << issue else unsaved_issues << orig_issue end end

@issues.each do |orig_issue| issue = update_issue(orig_issue) call_hook(:controller_issues_bulk_edit_before_save, { stuff })
if issue.save saved_issues << issue else unsaved_issues << orig_issue end end

def update_issues @issues.each do |orig_issue| issue = update_issue(orig_issue) call_hook(:controller_issues_bulk_edit_before_save, {
stuff }) if issue.save saved_issues << issue else unsaved_issues << orig_issue end end end

def bulk_update @issues.sort! updater = BulkIssuesUpdater.new( @issues, parse_params_for_bulk_issue_attributes(params), params )
updater.update_issues if unsaved_issues.empty? flash[:notice] = l(:notice_successful_update) unless saved_issues.empty? if params[:follow] if @issues.size == 1 && saved_issues.size == 1 redirect_to issue_path(saved_issues.first) elsif saved_issues.map(&:project).uniq.size == 1 redirect_to project_issues_path(saved_issues.map(&:project).first) end else redirect_back_or_default _project_issues_path(@project) end else @saved_issues = @issues @unsaved_issues = unsaved_issues @issues = Issue.visible.where(:id => @unsaved_issues.map(&:id)).to_a bulk_edit render :action => 'bulk_edit' end end

updater = BulkIssuesUpdater.new( @issues, parse_params_for_bulk_issue_attributes(params), params ) updater.update_issues

class BulkIssuesUpdater def initialize(issues, attributes, params) end def update_issues end
private def update_issue(original_issue) end end

form objects

class ValueForm include ActiveModel::Validations attr_accessor :value validates :value, presence: true
end

form = ValueForm.new form.valid? #=> false form.value = 3 form.valid?
#=> true

multiple records Picture by BrokenSphere / CC BY-SA 3.0

if dog.valid? && cat.valid? && mouse.valid? dog.save cat.save mouse.save end

class PetFamilyForm attr_accessor :dog, :cat, :mouse validates :cat, :is_on_dog validates
:mouse, :is_on_cat def save dog.save cat.save mouse.save end end

diﬀerent rules

class User < AR::Base validates :email, presence: true length: {
maximum: 255 } end

clas NormalUserForm validates :email, presence: true end class UserWithoutEmailForm #
no need for an email! end

class User < AR::Base validates :email, presence: true on: :dummy_user
end

user.save(context: :dummy_user)

gem ‘reform’ gem ‘active_type’

refactor time! Adventure Time by jm08191998 / CC BY-SA 3.0

form objects

convenience_store else grab_chocolate go_in_line take_out_wallet count_money if enough_money? hand_money receive_change go_back_home eat_chocolate else go_back_home eat_fruits_instead end end end

convenience_store else grab_chocolate if payment_form.enough_money? payment_form.pay go_back_home eat_chocolate else go_back_home eat_fruits_instead end end end

before_action

return eat_nothing unless parents_agree?

def check_permission return eat_nothing unless parents_agree? end

before_action :check_permission def check_permission eat_nothing unless parents_agree? end

def emilie_eats_chocolate go_to_grocery if grocery_is_closed? redirect_to convenience_store else grab_chocolate if
payment_form.enough_money? payment_form.pay go_back_home eat_chocolate else go_back_home eat_fruits_instead end end end

exit branches

def emilie_eats_chocolate go_to_grocery if grocery_is_closed? redirect_to convenience_store else grab_chocolate if
payment_form.enough_money? payment_form.pay go_back_home eat_chocolate else go_back_home eat_fruits_instead end end end

focus Macro Raspas de Chocolate by Thavlosk / CC BY-SA
3.0

def go_to_grocery visit :grocery if grocery_is_closed? redirect_to convenience_store end end

def grab_chocolate return if performed? ... end

all steps may exit

def go_to_grocery visit :grocery if grocery_is_closed? redirect_to convenience_store end end

def go_to_grocery visit :grocery if grocery_is_closed? redirect_to convenience_store halt end
end

catch throw Brett Gardner leaping catch by Keith Allison /
CC BY-SA 2.0

def go_to_grocery visit :grocery if grocery_is_closed? redirect_to convenience_store throw :halt
end end

def emilie_eats_chocolate catch(:halt) do … end end

around_action :catch_halt def catch_halt catch(:halt) { yield } end

haltable do some_method end def some_method halt end

def emilie_eats_chocolate haltable do go_to_grocery grab_chocolate pay go_back_home eat_chocolate end
end

does it work?

before_action :retrieve_customer_session, :handle_theme_switching, :ensure_order_created_if_paid, :set_checkout_cookie, :set_tracking_tokens, :cleanup_params, :funnel_tracking

def update haltable do handle_checkout_if_completed ensure_customer_has_access_to_checkout ensure_checkout_not_processing apply_external_params scrub_checkout update_and_validate_checkout
ensure_checkout_synced ensure_checkout_has_no_stock_problems handle_updated_checkout end end

def update_checkout updater = Checkout::Updater.new(checkout) updater.update(checkout_params) end

last words

easy stuff

service objects

form objects

exit branches

questions?

thanks :)

exit branches service objects

function update(request, response) { }

function update(request, response) { response.write(“Hello World") }

function update(request, response) { response.redirect("home.html") }

def update updater = WorldUpdater.new updater.update_world(params, response) end

def update_world(params, response) # Very complex logic here response.location =
resource_path end

def update_world(params, response) # Very complex logic here response.location =
resource_path halt end

questions?

thanks :)

Simplifying Controllers - Confoo 2015

Simplifying Controllers - Confoo 2015

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