Show abstract, details, pitch diff in proposal

Gemfile

@@ -43,6 +43,9 @@ gem 'react-rails'
 
 gem 'sidekiq'
 
+gem 'diffy'
+gem 'paper_trail'
+
 group :production do
   gem 'rails_12factor'
   gem 'rack-timeout', '~> 0.5'

Gemfile.lock

@@ -112,6 +112,7 @@ GEM
       responders
       warden (~> 1.2.3)
     diff-lcs (1.3)
+    diffy (3.3.0)
     dotenv (2.5.0)
     dotenv-rails (2.5.0)
       dotenv (= 2.5.0)
@@ -252,6 +253,9 @@ GEM
       omniauth-oauth (~> 1.1)
       rack
     orm_adapter (0.5.0)
+    paper_trail (10.3.1)
+      activerecord (>= 4.2)
+      request_store (~> 1.1)
     pg (1.1.3)
     pry (0.12.2)
       coderay (~> 1.1.0)
@@ -450,6 +454,7 @@ DEPENDENCIES
   country_select (~> 1.3.1)
   database_cleaner (~> 1.6.0)
   devise (~> 4.7)
+  diffy
   dotenv-rails
   draper (~> 3.0.1)
   factory_bot_rails
@@ -471,6 +476,7 @@ DEPENDENCIES
   nokogiri (~> 1.10.8)
   omniauth-github
   omniauth-twitter
+  paper_trail
   pg
   pry-rails
   pry-remote

app/assets/stylesheets/modules/_proposal.scss

@@ -267,3 +267,9 @@ div.col-md-4 {
     padding-bottom: 0;
   }
 }
+
+.diff-view {
+  margin-bottom: 10px;
+  padding-bottom: 10px;
+  border-bottom: 1px solid grey;
+}

app/controllers/application_controller.rb

@@ -2,8 +2,6 @@ class ApplicationController < ActionController::Base
   include Pundit
   include ActivateNavigation
   rescue_from Pundit::NotAuthorizedError, with: :user_not_authorized
-  #after_action :verify_authorized, except: :index
-  #after_action :verify_policy_scoped, only: :index
 
   require "csv"
   # Prevent CSRF attacks by raising an exception.
@@ -18,6 +16,7 @@ class ApplicationController < ActionController::Base
   helper_method :schedule_mode?
   helper_method :program_tracks
 
+  before_action :set_paper_trail_whodunnit
   before_action :current_event
   before_action :configure_permitted_parameters, if: :devise_controller?
 

app/helpers/proposal_helper.rb

@@ -1,4 +1,11 @@
 module ProposalHelper
+  def diff(content1, content2)
+     changes = Diffy::Diff.new(content1, content2,
+                               include_plus_and_minus_in_html: true,
+                               include_diff_info: true)
+     changes.to_s.present? ? changes.to_s(:html).html_safe : 'No Changes'
+  end
+
   def rating_tooltip
       <<-HTML
       <p><strong>Ratings Guide</strong></p>

app/models/proposal.rb

@@ -28,6 +28,8 @@ class Proposal < ApplicationRecord
   serialize :last_change
   serialize :proposal_data, Hash
 
+  has_paper_trail only: [:title, :abstract, :details, :pitch]
+
   attr_accessor :tags, :review_tags, :updating_user
 
   accepts_nested_attributes_for :public_comments, reject_if: Proc.new { |comment_attributes| comment_attributes[:body].blank? }
@@ -249,6 +251,10 @@ def has_reviewer_activity?
     ratings.present? || has_reviewer_comments?
   end
 
+  def changeset_fields
+    versions[1..]&.map(&:changeset)&.flat_map(&:keys)&.uniq
+  end
+
   private
 
   def abstract_length

app/views/proposals/_contents.html.haml

@@ -22,3 +22,14 @@
       %div
       = value.capitalize
       %div
+
+- unless proposal.changeset_fields.empty?
+  %h2.fieldset-legend Proposal Diff...
+  - proposal.versions.each do |version|
+    .diff-view
+      - version.changeset.each do |k, (old, new)|
+        %h3.control-label= k.titleize
+        %div= diff old, new
+
+:css
+  = #{Diffy::CSS}

db/migrate/20200223215131_create_versions.rb

@@ -0,0 +1,36 @@
+# This migration creates the `versions` table, the only schema PT requires.
+# All other migrations PT provides are optional.
+class CreateVersions < ActiveRecord::Migration[5.2]
+
+  # The largest text column available in all supported RDBMS is
+  # 1024^3 - 1 bytes, roughly one gibibyte.  We specify a size
+  # so that MySQL will use `longtext` instead of `text`.  Otherwise,
+  # when serializing very large objects, `text` might not be big enough.
+  TEXT_BYTES = 1_073_741_823
+
+  def change
+    create_table :versions do |t|
+      t.string   :item_type, {:null=>false}
+      t.integer  :item_id,   null: false, limit: 8
+      t.string   :event,     null: false
+      t.string   :whodunnit
+      t.text     :object, limit: TEXT_BYTES
+
+      # Known issue in MySQL: fractional second precision
+      # -------------------------------------------------
+      #
+      # MySQL timestamp columns do not support fractional seconds unless
+      # defined with "fractional seconds precision". MySQL users should manually
+      # add fractional seconds precision to this migration, specifically, to
+      # the `created_at` column.
+      # (https://dev.mysql.com/doc/refman/5.6/en/fractional-seconds.html)
+      #
+      # MySQL users should also upgrade to at least rails 4.2, which is the first
+      # version of ActiveRecord with support for fractional seconds in MySQL.
+      # (https://github.com/rails/rails/pull/14359)
+      #
+      t.datetime :created_at
+    end
+    add_index :versions, %i(item_type item_id)
+  end
+end

db/migrate/20200223215132_add_object_changes_to_versions.rb

@@ -0,0 +1,12 @@
+# This migration adds the optional `object_changes` column, in which PaperTrail
+# will store the `changes` diff for each update event. See the readme for
+# details.
+class AddObjectChangesToVersions < ActiveRecord::Migration[5.2]
+  # The largest text column available in all supported RDBMS.
+  # See `create_versions.rb` for details.
+  TEXT_BYTES = 1_073_741_823
+
+  def change
+    add_column :versions, :object_changes, :text, limit: TEXT_BYTES
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2018_01_11_175100) do
+ActiveRecord::Schema.define(version: 2020_02_23_215132) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -250,5 +250,16 @@
     t.index ["uid"], name: "index_users_on_uid"
   end
 
+  create_table "versions", force: :cascade do |t|
+    t.string "item_type", null: false
+    t.bigint "item_id", null: false
+    t.string "event", null: false
+    t.string "whodunnit"
+    t.text "object"
+    t.datetime "created_at"
+    t.text "object_changes"
+    t.index ["item_type", "item_id"], name: "index_versions_on_item_type_and_item_id"
+  end
+
   add_foreign_key "session_formats", "events"
 end