optimize queries

app/controllers/admin/base_controller.rb

@@ -3,9 +3,14 @@
 module Admin
   class BaseController < ApplicationController
     before_action :verify_user_admin
+    before_action :load_all_conferences
 
     private
 
+    def load_all_conferences
+      @conferences = Conference.all
+    end
+
     def current_ability
       @current_ability ||= AdminAbility.new(current_user)
     end

app/controllers/application_controller.rb

@@ -5,7 +5,6 @@ class ApplicationController < ActionController::Base
   include ApplicationHelper
   add_flash_types :error
   protect_from_forgery with: :exception, prepend: true
-  before_action :get_conferences
   before_action :store_location
   # Ensure every controller authorizes resource or skips authorization (skip_authorization_check)
   check_authorization unless: :devise_controller?
@@ -37,10 +36,6 @@ class ApplicationController < ActionController::Base
     end
   end
 
-  def get_conferences
-    @conferences = Conference.all
-  end
-
   def current_ability
     @current_ability ||= Ability.new(current_user)
   end

app/controllers/conferences_controller.rb

@@ -6,8 +6,9 @@ class ConferencesController < ApplicationController
   load_and_authorize_resource find_by: :short_title, except: :show
 
   def index
-    @current = Conference.where('end_date >= ?', Date.current).reorder(start_date: :asc)
-    @antiquated = @conferences - @current
+    @current, @antiquated = Conference.reorder(start_date: :asc).all.partition do |conference|
+      conference.end_date >= Date.current
+    end
   end
 
   def show

app/controllers/schedules_controller.rb

@@ -6,39 +6,52 @@ class SchedulesController < ApplicationController
   before_action :respond_to_options
   load_resource :conference, find_by: :short_title
   load_resource :program, through: :conference, singleton: true, except: :index
+  before_action :load_withdrawn_event_schedules, only: [:show, :events]
 
   def show
-    @rooms = @conference.venue.rooms if @conference.venue
-    schedules = @program.selected_event_schedules
-    unless schedules
+    @event_schedules = @program.selected_event_schedules(
+      includes: [{ event: %i[event_type speakers submitter] }]
+    )
+
+    unless @event_schedules
       redirect_to events_conference_schedule_path(@conference.short_title)
+      return
     end
 
-    @events_xml = schedules.map(&:event).group_by{ |event| event.time.to_date } if schedules
-    @dates = @conference.start_date..@conference.end_date
-    @step_minutes = @program.schedule_interval.minutes
-    @conf_start = @conference.start_hour
-    @conf_period = @conference.end_hour - @conf_start
+    respond_to do |format|
+      format.xml do
+        @events_xml = @event_schedules.map(&:event).group_by{ |event| event.time.to_date } if @event_schedules
+      end
 
-    # the schedule takes you to today if it is a date of the schedule
-    @current_day = @conference.current_conference_day
-    @day = @current_day.present? ? @current_day : @dates.first
-    unless @current_day
-      # the schedule takes you to the current time if it is beetween the start and the end time.
-      @hour_column = @conference.hours_from_start_time(@conf_start, @conference.end_hour)
+      format.html do
+        @rooms = @conference.venue.rooms if @conference.venue
+        @dates = @conference.start_date..@conference.end_date
+        @step_minutes = @program.schedule_interval.minutes
+        @conf_start = @conference.start_hour
+        @conf_period = @conference.end_hour - @conf_start
+
+        # the schedule takes you to today if it is a date of the schedule
+        @current_day = @conference.current_conference_day
+        @day = @current_day.present? ? @current_day : @dates.first
+        unless @current_day
+          # the schedule takes you to the current time if it is beetween the start and the end time.
+          @hour_column = @conference.hours_from_start_time(@conf_start, @conference.end_hour)
+        end
+        # Ids of the @event_schedules of confrmed self_organized tracks along with the selected_schedule_id
+        @selected_schedules_ids = [@conference.program.selected_schedule_id]
+        @conference.program.tracks.self_organized.confirmed.each do |track|
+          @selected_schedules_ids << track.selected_schedule_id
+        end
+        @selected_schedules_ids.compact!
+      end
     end
-    # Ids of the schedules of confrmed self_organized tracks along with the selected_schedule_id
-    @selected_schedules_ids = [@conference.program.selected_schedule_id]
-    @conference.program.tracks.self_organized.confirmed.each do |track|
-      @selected_schedules_ids << track.selected_schedule_id
-    end
-    @selected_schedules_ids.compact!
   end
 
   def events
     @dates = @conference.start_date..@conference.end_date
-
-    @events_schedules = @program.selected_event_schedules
+    @events_schedules = @program.selected_event_schedules(
+      includes: [:room, { event: %i[track event_type speakers submitter] }]
+    )
     @events_schedules = [] unless @events_schedules
 
     @unscheduled_events = @program.events.confirmed - @events_schedules.map(&:event)
@@ -54,4 +67,10 @@ class SchedulesController < ApplicationController
       format.html { head :ok }
     end if request.options?
   end
+
+  def load_withdrawn_event_schedules
+    # Avoid making repetitive EXISTS queries for these later.
+    # See usage in EventsHelper#canceled_replacement_event_label
+    @withdrawn_event_schedules = EventSchedule.withdrawn_or_canceled_event_schedules(@program.schedule_ids)
+  end
 end