Rudimentary export

app/controllers/application_controller.rb

@@ -1,3 +1,5 @@
+require 'csv'
+
 class ApplicationController < ActionController::Base
   # Prevent CSRF attacks by raising an exception.
   # For APIs, you may want to use :null_session instead.

app/controllers/home_controller.rb

@@ -1,4 +1,9 @@
 class HomeController < ApplicationController
   def index
   end
+
+  def ratings
+    @talks = Talk.ordered_by_rating
+    @ratings = Ratings.new
+  end
 end

app/models/ratings.rb

@@ -0,0 +1,16 @@
+class Ratings
+  @ratings = Hash.new(0)
+
+  def initialize
+    ratings = TalkPreference.all.pluck(:talks).reduce(Hash.new(0)) do |result, talks|
+      talks.map(&:to_i).each { |talk| result[talk] += 1 }
+      result
+    end.to_h
+
+    @ratings = Hash.new(0).merge!(ratings)
+  end
+
+  def [](id)
+    @ratings[id]
+  end
+end

app/models/talk.rb

@@ -1,4 +1,9 @@
 class Talk < ActiveResource::Base
   self.site = "https://cfp.openfest.org/api/conferences/2"
   self.element_name = "event"
+
+  def self.ordered_by_rating
+    ratings = Ratings.new
+    all.sort { |left, right| ratings[right.id] <=> ratings[left.id] }
+  end
 end

app/views/home/_talk.csv.erb

@@ -0,0 +1 @@
+<%= CSV.generate_line([talk.id, talk.event_type.name, talk.title, talk.subtitle, @ratings[talk.id]]).html_safe -%>

app/views/home/ratings.csv.erb

@@ -0,0 +1,3 @@
+<%- headers = ['ID', 'Type', 'Title', 'Subtitle', 'Votes'] -%>
+<%= CSV.generate_line headers -%>
+<%= render partial: 'talk', collection: @talks %>

config/routes.rb

@@ -1,4 +1,5 @@
 Rails.application.routes.draw do
   resources :talk_preferences, only: [:index, :show, :create, :update]
   root to: 'home#index'
+  get 'ratings' => 'home#ratings'
 end