From 7cff5e0da607f4806b38f09ffd1754aac0f3673d Mon Sep 17 00:00:00 2001
From: Nishanth Vijayan <nishanththegr8@gmail.com>
Date: Sat, 6 Aug 2016 17:22:53 +0530
Subject: [PATCH 1/9] Allow organizers to view changes in a per conference
 basis

---
 app/controllers/admin/versions_controller.rb | 10 ++++++++--
 app/views/admin/versions/index.html.haml     | 16 ++++++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/app/controllers/admin/versions_controller.rb b/app/controllers/admin/versions_controller.rb
index 07108d38..b5eec406 100644
--- a/app/controllers/admin/versions_controller.rb
+++ b/app/controllers/admin/versions_controller.rb
@@ -4,8 +4,14 @@ module Admin
 
     def index
       authorize! :index, PaperTrail::Version.new(item_type: 'User')
-      conf_ids_for_organizer = current_user.is_admin? ? Conference.pluck(:id) : Conference.with_role(:organizer, current_user).pluck(:id)
-      @versions = PaperTrail::Version.where(["conference_id IN (?) OR item_type = 'User'", conf_ids_for_organizer])
+      @conf_ids_for_organizer = current_user.is_admin? ? Conference.pluck(:id) : Conference.with_role(:organizer, current_user).pluck(:id)
+      @conference_id = params[:conference_id].to_i unless params[:conference_id].nil?
+      if @conference_id.nil?
+        @versions = PaperTrail::Version.where(["conference_id IN (?) OR item_type = 'User'", @conf_ids_for_organizer])
+      else
+        @versions = PaperTrail::Version.where(['conference_id IN (?)', (@conf_ids_for_organizer & [@conference_id])]).
+                                                                    where.not(item_type: 'User')
+      end
     end
 
     def revert_attribute
diff --git a/app/views/admin/versions/index.html.haml b/app/views/admin/versions/index.html.haml
index 69af134b..5408694d 100644
--- a/app/views/admin/versions/index.html.haml
+++ b/app/views/admin/versions/index.html.haml
@@ -1,6 +1,22 @@
 .row
   .col-md-12
     .page-header
+
+      .dropdown.pull-right
+        %button.btn.btn-success.dropdown-toggle{'data-toggle' => 'dropdown', type: 'button'}
+          - if @conference_id.nil?
+            All Conferences & Users
+          - elsif @conf_ids_for_organizer.include?(@conference_id)
+            = Conference.find(@conference_id).short_title
+          - else
+            Filter By Conference
+          %span.caret
+        %ul.dropdown-menu
+          %li= link_to 'All Conferences & Users',  admin_revision_history_path
+          - @conf_ids_for_organizer.each do |conf_id|
+            - conference = Conference.find(conf_id)
+            %li= link_to conference.short_title,  admin_revision_history_path(conference_id: conference.id)
+
       %h1 Revision History
       %p.text-muted
         Log of changes made to conferences and associated resources

From 614da6003ba8ae6f77459f66ebcd3fa455949f34 Mon Sep 17 00:00:00 2001
From: Nishanth Vijayan <nishanththegr8@gmail.com>
Date: Sat, 6 Aug 2016 17:47:46 +0530
Subject: [PATCH 2/9] Display error if non existant conference's versions are
 queried

---
 app/controllers/admin/versions_controller.rb | 7 +++++--
 app/views/admin/versions/index.html.haml     | 7 +------
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/app/controllers/admin/versions_controller.rb b/app/controllers/admin/versions_controller.rb
index b5eec406..16f38c15 100644
--- a/app/controllers/admin/versions_controller.rb
+++ b/app/controllers/admin/versions_controller.rb
@@ -8,9 +8,12 @@ module Admin
       @conference_id = params[:conference_id].to_i unless params[:conference_id].nil?
       if @conference_id.nil?
         @versions = PaperTrail::Version.where(["conference_id IN (?) OR item_type = 'User'", @conf_ids_for_organizer])
+      elsif !Conference.exists?(id: @conference_id)
+        redirect_to admin_revision_history_path, error: "Conference with ID #{@conference_id} does not exist!"
+        return
       else
-        @versions = PaperTrail::Version.where(['conference_id IN (?)', (@conf_ids_for_organizer & [@conference_id])]).
-                                                                    where.not(item_type: 'User')
+        authorize! :index, PaperTrail::Version.new(conference_id: @conference_id)
+        @versions = PaperTrail::Version.where(conference_id:  @conference_id)
       end
     end
 
diff --git a/app/views/admin/versions/index.html.haml b/app/views/admin/versions/index.html.haml
index 5408694d..456cda33 100644
--- a/app/views/admin/versions/index.html.haml
+++ b/app/views/admin/versions/index.html.haml
@@ -4,12 +4,7 @@
 
       .dropdown.pull-right
         %button.btn.btn-success.dropdown-toggle{'data-toggle' => 'dropdown', type: 'button'}
-          - if @conference_id.nil?
-            All Conferences & Users
-          - elsif @conf_ids_for_organizer.include?(@conference_id)
-            = Conference.find(@conference_id).short_title
-          - else
-            Filter By Conference
+          = @conference_id.nil? ? 'All Conferences & Users' : Conference.find(@conference_id).short_title
           %span.caret
         %ul.dropdown-menu
           %li= link_to 'All Conferences & Users',  admin_revision_history_path

From 71c8dd412749c32bd8c708d61286cff8f0b41cb4 Mon Sep 17 00:00:00 2001
From: Nishanth Vijayan <nishanththegr8@gmail.com>
Date: Sat, 6 Aug 2016 18:48:36 +0530
Subject: [PATCH 3/9] Add controller tests for admin::versions#index

---
 .../controllers/admin/versions_controller_spec.rb | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/spec/controllers/admin/versions_controller_spec.rb b/spec/controllers/admin/versions_controller_spec.rb
index 4694837d..d2baec3d 100644
--- a/spec/controllers/admin/versions_controller_spec.rb
+++ b/spec/controllers/admin/versions_controller_spec.rb
@@ -97,5 +97,20 @@ describe Admin::VersionsController do
         expect(flash[:error]).to match('Revert failed. Attribute missing or invalid')
       end
     end
+
+    describe 'GET #index' do
+      it 'raises error if conference_id is invalid' do
+        sign_in admin
+        get :index, conference_id: 88
+        expect(flash[:error]).to match('Conference with ID 88 does not exist!')
+      end
+
+      it 'raises error if user is not an organizer of specified conference' do
+        user = create(:user)
+        sign_in user
+        get :index, conference_id: conference.id
+        expect(flash[:alert]).to match('You are not authorized to access this area.')
+      end
+    end
   end
 end

From 58a3913735e3db7932662f4ac6cfcf83b66d60fb Mon Sep 17 00:00:00 2001
From: Nishanth Vijayan <nishanththegr8@gmail.com>
Date: Mon, 15 Aug 2016 14:21:33 +0530
Subject: [PATCH 4/9] Use load_and_authorize_resource in versions controlller

---
 app/controllers/admin/versions_controller.rb | 20 +++++++-------------
 app/models/ability.rb                        |  5 ++---
 2 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/app/controllers/admin/versions_controller.rb b/app/controllers/admin/versions_controller.rb
index 16f38c15..7b02461a 100644
--- a/app/controllers/admin/versions_controller.rb
+++ b/app/controllers/admin/versions_controller.rb
@@ -1,26 +1,23 @@
 module Admin
   class VersionsController < Admin::BaseController
-    skip_authorization_check
+    load_and_authorize_resource class: PaperTrail::Version
 
     def index
       authorize! :index, PaperTrail::Version.new(item_type: 'User')
       @conf_ids_for_organizer = current_user.is_admin? ? Conference.pluck(:id) : Conference.with_role(:organizer, current_user).pluck(:id)
       @conference_id = params[:conference_id].to_i unless params[:conference_id].nil?
-      if @conference_id.nil?
-        @versions = PaperTrail::Version.where(["conference_id IN (?) OR item_type = 'User'", @conf_ids_for_organizer])
-      elsif !Conference.exists?(id: @conference_id)
+
+      unless @conference_id.nil? || Conference.exists?(id: @conference_id)
         redirect_to admin_revision_history_path, error: "Conference with ID #{@conference_id} does not exist!"
         return
-      else
-        authorize! :index, PaperTrail::Version.new(conference_id: @conference_id)
-        @versions = PaperTrail::Version.where(conference_id:  @conference_id)
       end
+
+      return unless @conference_id.present?
+      authorize! :index, PaperTrail::Version.new(conference_id: @conference_id)
+      @versions = @versions.where(conference_id:  @conference_id)
     end
 
     def revert_attribute
-      @version = PaperTrail::Version.find(params[:id])
-      authorize! :revert_attribute, @version
-
       if params[:attribute] && @version.changeset.reject{ |_, values| values[0].blank? && values[1].blank? }.keys.include?(params[:attribute])
         if @version.item[params[:attribute]] == @version.changeset[params[:attribute]][0]
           flash[:error] = 'The item is already in the state that you are trying to revert it back to'
@@ -42,9 +39,6 @@ module Admin
     end
 
     def revert_object
-      @version = PaperTrail::Version.find(params[:id])
-      authorize! :revert_object, @version
-
       if @version.event != 'create'
         if @version.reify.save
           flash[:notice] = 'The selected change was successfully reverted'
diff --git a/app/models/ability.rb b/app/models/ability.rb
index 760f43fe..699e4f54 100644
--- a/app/models/ability.rb
+++ b/app/models/ability.rb
@@ -178,9 +178,8 @@ class Ability
       role.resource_type == 'Conference' && (conf_ids_for_organizer.include? role.resource_id)
     end
 
-    can [:index, :revert_object, :revert_attribute], PaperTrail::Version do |version|
-      version.item_type == 'User' || (conf_ids_for_organizer.include? version.conference_id)
-    end
+    can [:index, :revert_object, :revert_attribute], PaperTrail::Version, item_type: 'User'
+    can [:index, :revert_object, :revert_attribute], PaperTrail::Version, conference_id: conf_ids_for_organizer
   end
 
   def signed_in_with_cfp_role(user)

From 5965bcf193e8804e9dca41e8f11086f25a441676 Mon Sep 17 00:00:00 2001
From: Nishanth Vijayan <nishanththegr8@gmail.com>
Date: Mon, 15 Aug 2016 15:44:20 +0530
Subject: [PATCH 5/9] Stop checking for non-existing conference_id in versions
 controller

---
 app/controllers/admin/versions_controller.rb       | 5 -----
 spec/controllers/admin/versions_controller_spec.rb | 6 ------
 2 files changed, 11 deletions(-)

diff --git a/app/controllers/admin/versions_controller.rb b/app/controllers/admin/versions_controller.rb
index 7b02461a..0020cf96 100644
--- a/app/controllers/admin/versions_controller.rb
+++ b/app/controllers/admin/versions_controller.rb
@@ -7,11 +7,6 @@ module Admin
       @conf_ids_for_organizer = current_user.is_admin? ? Conference.pluck(:id) : Conference.with_role(:organizer, current_user).pluck(:id)
       @conference_id = params[:conference_id].to_i unless params[:conference_id].nil?
 
-      unless @conference_id.nil? || Conference.exists?(id: @conference_id)
-        redirect_to admin_revision_history_path, error: "Conference with ID #{@conference_id} does not exist!"
-        return
-      end
-
       return unless @conference_id.present?
       authorize! :index, PaperTrail::Version.new(conference_id: @conference_id)
       @versions = @versions.where(conference_id:  @conference_id)
diff --git a/spec/controllers/admin/versions_controller_spec.rb b/spec/controllers/admin/versions_controller_spec.rb
index d2baec3d..6ebd3052 100644
--- a/spec/controllers/admin/versions_controller_spec.rb
+++ b/spec/controllers/admin/versions_controller_spec.rb
@@ -99,12 +99,6 @@ describe Admin::VersionsController do
     end
 
     describe 'GET #index' do
-      it 'raises error if conference_id is invalid' do
-        sign_in admin
-        get :index, conference_id: 88
-        expect(flash[:error]).to match('Conference with ID 88 does not exist!')
-      end
-
       it 'raises error if user is not an organizer of specified conference' do
         user = create(:user)
         sign_in user

From 51d569794f07d8568055c7e9c531c3e3248991a2 Mon Sep 17 00:00:00 2001
From: Nishanth Vijayan <nishanththegr8@gmail.com>
Date: Mon, 15 Aug 2016 16:42:12 +0530
Subject: [PATCH 6/9] Add conference specifc route to revision history page

---
 app/controllers/admin/versions_controller.rb       | 11 +++++------
 app/views/admin/versions/index.html.haml           |  7 +++----
 app/views/layouts/_admin_sidebar.html.haml         |  5 +++++
 config/routes.rb                                   |  2 ++
 spec/controllers/admin/versions_controller_spec.rb |  2 +-
 5 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/app/controllers/admin/versions_controller.rb b/app/controllers/admin/versions_controller.rb
index 0020cf96..34aeffd1 100644
--- a/app/controllers/admin/versions_controller.rb
+++ b/app/controllers/admin/versions_controller.rb
@@ -1,15 +1,14 @@
 module Admin
   class VersionsController < Admin::BaseController
+    load_resource :conference, find_by: :short_title
     load_and_authorize_resource class: PaperTrail::Version
 
     def index
-      authorize! :index, PaperTrail::Version.new(item_type: 'User')
-      @conf_ids_for_organizer = current_user.is_admin? ? Conference.pluck(:id) : Conference.with_role(:organizer, current_user).pluck(:id)
-      @conference_id = params[:conference_id].to_i unless params[:conference_id].nil?
+      @conf_ids_for_organizer = current_user.is_admin? ? Conference.pluck(:short_title) : Conference.with_role(:organizer, current_user).pluck(:short_title)
 
-      return unless @conference_id.present?
-      authorize! :index, PaperTrail::Version.new(conference_id: @conference_id)
-      @versions = @versions.where(conference_id:  @conference_id)
+      return unless @conference.present?
+      authorize! :index, PaperTrail::Version.new(conference_id: @conference.id)
+      @versions = @versions.where(conference_id:  @conference.id)
     end
 
     def revert_attribute
diff --git a/app/views/admin/versions/index.html.haml b/app/views/admin/versions/index.html.haml
index 456cda33..d7cc9798 100644
--- a/app/views/admin/versions/index.html.haml
+++ b/app/views/admin/versions/index.html.haml
@@ -4,13 +4,12 @@
 
       .dropdown.pull-right
         %button.btn.btn-success.dropdown-toggle{'data-toggle' => 'dropdown', type: 'button'}
-          = @conference_id.nil? ? 'All Conferences & Users' : Conference.find(@conference_id).short_title
+          = @conference.nil? ? 'All Conferences & Users' : @conference.short_title
           %span.caret
         %ul.dropdown-menu
           %li= link_to 'All Conferences & Users',  admin_revision_history_path
-          - @conf_ids_for_organizer.each do |conf_id|
-            - conference = Conference.find(conf_id)
-            %li= link_to conference.short_title,  admin_revision_history_path(conference_id: conference.id)
+          - @conf_ids_for_organizer.each do |conference_short_title|
+            %li= link_to conference_short_title,  admin_conference_revision_history_path(conference_id: conference_short_title)
 
       %h1 Revision History
       %p.text-muted
diff --git a/app/views/layouts/_admin_sidebar.html.haml b/app/views/layouts/_admin_sidebar.html.haml
index 62645e0c..0d2fe3c0 100644
--- a/app/views/layouts/_admin_sidebar.html.haml
+++ b/app/views/layouts/_admin_sidebar.html.haml
@@ -136,3 +136,8 @@
       = link_to(admin_conference_roles_path(@conference.short_title)) do
         %span.fa.fa-group
         Roles
+  - if can? :index, PaperTrail::Version.new(item_type: 'User')
+    %li{:class=> active_nav_li(admin_conference_revision_history_path(@conference.short_title))}
+      = link_to(admin_conference_revision_history_path(@conference.short_title)) do
+        %span.fa.fa-history
+        Revision History
diff --git a/config/routes.rb b/config/routes.rb
index 7bd331d9..6426b0d7 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -95,6 +95,8 @@ Osem::Application.routes.draw do
           patch :update_conference
         end
       end
+
+      get '/revision_history' => 'versions#index'
     end
 
     get '/revision_history' => 'versions#index'
diff --git a/spec/controllers/admin/versions_controller_spec.rb b/spec/controllers/admin/versions_controller_spec.rb
index 6ebd3052..f1400e3b 100644
--- a/spec/controllers/admin/versions_controller_spec.rb
+++ b/spec/controllers/admin/versions_controller_spec.rb
@@ -102,7 +102,7 @@ describe Admin::VersionsController do
       it 'raises error if user is not an organizer of specified conference' do
         user = create(:user)
         sign_in user
-        get :index, conference_id: conference.id
+        get :index, conference_id: conference.short_title
         expect(flash[:alert]).to match('You are not authorized to access this area.')
       end
     end

From 3a3d01150a0f4e0edfa2d1be11e99d5c9a32117f Mon Sep 17 00:00:00 2001
From: Nishanth Vijayan <nishanththegr8@gmail.com>
Date: Wed, 17 Aug 2016 05:05:46 +0530
Subject: [PATCH 7/9] Allow other roles to view revision_history only with the
 versions they have access

---
 app/controllers/admin/versions_controller.rb     | 2 +-
 app/models/ability.rb                            | 8 ++++++--
 app/views/admin/versions/index.html.haml         | 2 +-
 app/views/layouts/_admin_sidebar.html.haml       | 2 +-
 app/views/layouts/_admin_sidebar_index.html.haml | 2 +-
 app/views/layouts/_user_menu.html.haml           | 2 +-
 spec/features/ability_spec.rb                    | 7 +++++--
 7 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/app/controllers/admin/versions_controller.rb b/app/controllers/admin/versions_controller.rb
index 34aeffd1..69f57bb9 100644
--- a/app/controllers/admin/versions_controller.rb
+++ b/app/controllers/admin/versions_controller.rb
@@ -4,7 +4,7 @@ module Admin
     load_and_authorize_resource class: PaperTrail::Version
 
     def index
-      @conf_ids_for_organizer = current_user.is_admin? ? Conference.pluck(:short_title) : Conference.with_role(:organizer, current_user).pluck(:short_title)
+      @conf_ids_with_role = current_user.is_admin? ? Conference.pluck(:short_title) : Conference.with_role([:organizer, :cfp, :info_desk], current_user).pluck(:short_title)
 
       return unless @conference.present?
       authorize! :index, PaperTrail::Version.new(conference_id: @conference.id)
diff --git a/app/models/ability.rb b/app/models/ability.rb
index 699e4f54..773195f2 100644
--- a/app/models/ability.rb
+++ b/app/models/ability.rb
@@ -211,8 +211,10 @@ class Ability
       (Conference.with_role(:cfp, user).pluck(:id).include? role.resource_id)
     end
 
-    can [:index, :revert_object, :revert_attribute], PaperTrail::Version, item_type: 'Event', conference_id: conf_ids_for_cfp
-    can [:index, :revert_object, :revert_attribute], PaperTrail::Version do |version|
+    can [:index, :revert_object, :revert_attribute], PaperTrail::Version,
+        item_type: %w(Event EventType Track DifficultyLevel EmailSettings Room Cfp Program Comment), conference_id: conf_ids_for_cfp
+    can [:index, :revert_object, :revert_attribute], PaperTrail::Version,
+        ["item_type = 'Commercial' AND conference_id IN (?) AND (object LIKE '%Event%' OR object_changes LIKE '%Event%')", conf_ids_for_cfp] do |version|
       version.item_type == 'Commercial' && conf_ids_for_cfp.include?(version.conference_id) &&
       (version.object.to_s.include?('Event') || version.object_changes.to_s.include?('Event'))
     end
@@ -237,6 +239,8 @@ class Ability
       role.resource_type == 'Conference' && role.name == 'info_desk' &&
       (Conference.with_role(:info_desk, user).pluck(:id).include? role.resource_id)
     end
+
+    can [:index, :revert_object, :revert_attribute], PaperTrail::Version, item_type: 'Registration', conference_id: conf_ids_for_info_desk
   end
 
   def signed_in_with_volunteers_coordinator_role(user)
diff --git a/app/views/admin/versions/index.html.haml b/app/views/admin/versions/index.html.haml
index d7cc9798..860419af 100644
--- a/app/views/admin/versions/index.html.haml
+++ b/app/views/admin/versions/index.html.haml
@@ -8,7 +8,7 @@
           %span.caret
         %ul.dropdown-menu
           %li= link_to 'All Conferences & Users',  admin_revision_history_path
-          - @conf_ids_for_organizer.each do |conference_short_title|
+          - @conf_ids_with_role.each do |conference_short_title|
             %li= link_to conference_short_title,  admin_conference_revision_history_path(conference_id: conference_short_title)
 
       %h1 Revision History
diff --git a/app/views/layouts/_admin_sidebar.html.haml b/app/views/layouts/_admin_sidebar.html.haml
index 0d2fe3c0..eab6a74b 100644
--- a/app/views/layouts/_admin_sidebar.html.haml
+++ b/app/views/layouts/_admin_sidebar.html.haml
@@ -136,7 +136,7 @@
       = link_to(admin_conference_roles_path(@conference.short_title)) do
         %span.fa.fa-group
         Roles
-  - if can? :index, PaperTrail::Version.new(item_type: 'User')
+  - if can?(:index, PaperTrail::Version.new(conference_id: @conference.id, item_type: 'Event')) || can?(:index, PaperTrail::Version.new(conference_id: @conference.id, item_type: 'Registration'))
     %li{:class=> active_nav_li(admin_conference_revision_history_path(@conference.short_title))}
       = link_to(admin_conference_revision_history_path(@conference.short_title)) do
         %span.fa.fa-history
diff --git a/app/views/layouts/_admin_sidebar_index.html.haml b/app/views/layouts/_admin_sidebar_index.html.haml
index 4ae56dce..30ad5dcb 100644
--- a/app/views/layouts/_admin_sidebar_index.html.haml
+++ b/app/views/layouts/_admin_sidebar_index.html.haml
@@ -27,7 +27,7 @@
       = link_to(admin_users_path) do
         %span.fa.fa-user
         Users
-  - if can? :index, PaperTrail::Version.new(item_type: 'User')
+  - if can? :index, PaperTrail::Version
     %li
       = link_to(admin_revision_history_path) do
         %span.fa.fa-history
diff --git a/app/views/layouts/_user_menu.html.haml b/app/views/layouts/_user_menu.html.haml
index 95c7937e..50aa14d3 100644
--- a/app/views/layouts/_user_menu.html.haml
+++ b/app/views/layouts/_user_menu.html.haml
@@ -44,7 +44,7 @@
     = link_to(admin_users_path) do
       %span.fa.fa-user
       Users
-- if can? :index, PaperTrail::Version.new(item_type: 'User')
+- if can? :index, PaperTrail::Version
   %li
     = link_to(admin_revision_history_path) do
       %span.fa.fa-history
diff --git a/spec/features/ability_spec.rb b/spec/features/ability_spec.rb
index 2bcd8331..d5462db6 100644
--- a/spec/features/ability_spec.rb
+++ b/spec/features/ability_spec.rb
@@ -56,6 +56,7 @@ feature 'Has correct abilities' do
     expect(page).to have_link('Difficulty Levels', href: "/admin/conferences/#{conference1.short_title}/program/difficulty_levels")
     expect(page).to have_link('Questions', href: "/admin/conferences/#{conference1.short_title}/questions")
     expect(page).to have_link('Roles', href: "/admin/conferences/#{conference1.short_title}/roles")
+    expect(page).to have_link('Revision History', href: "/admin/conferences/#{conference1.short_title}/revision_history")
 
     visit edit_admin_conference_path(conference1.short_title)
     expect(current_path).to eq(edit_admin_conference_path(conference1.short_title))
@@ -137,6 +138,7 @@ feature 'Has correct abilities' do
     expect(page).to have_link('Difficulty Levels', href: "/admin/conferences/#{conference2.short_title}/program/difficulty_levels")
     expect(page).to_not have_link('Questions', href: "/admin/conferences/#{conference2.short_title}/questions")
     expect(page).to have_link('Roles', href: "/admin/conferences/#{conference2.short_title}/roles")
+    expect(page).to have_link('Revision History', href: "/admin/conferences/#{conference2.short_title}/revision_history")
 
     visit edit_admin_conference_path(conference2.short_title)
     expect(current_path).to eq(root_path)
@@ -181,7 +183,7 @@ feature 'Has correct abilities' do
     expect(current_path).to eq(root_path)
 
     visit admin_revision_history_path
-    expect(current_path).to eq(root_path)
+    expect(current_path).to eq(admin_revision_history_path)
   end
 
   scenario 'when user is info desk' do
@@ -214,6 +216,7 @@ feature 'Has correct abilities' do
     expect(page).to_not have_link('Difficulty levels', href: "/admin/conferences/#{conference3.short_title}/program/difficulty_levels")
     expect(page).to have_link('Questions', href: "/admin/conferences/#{conference3.short_title}/questions")
     expect(page).to have_link('Roles', href: "/admin/conferences/#{conference3.short_title}/roles")
+    expect(page).to have_link('Revision History', href: "/admin/conferences/#{conference3.short_title}/revision_history")
 
     visit edit_admin_conference_path(conference3.short_title)
     expect(current_path).to eq(root_path)
@@ -258,6 +261,6 @@ feature 'Has correct abilities' do
     expect(current_path).to eq(root_path)
 
     visit admin_revision_history_path
-    expect(current_path).to eq(root_path)
+    expect(current_path).to eq(admin_revision_history_path)
   end
 end

From ac420ab3a432244369d143bbff76f2d54fa3381e Mon Sep 17 00:00:00 2001
From: Nishanth Vijayan <nishanththegr8@gmail.com>
Date: Tue, 16 Aug 2016 15:15:01 +0530
Subject: [PATCH 8/9] Handle versions where conference_id is not set

There are version records that exist prior to the when changelog was introduced
These versions do not have conference_id set.
---
 .../versions/_object_desc_and_link.html.haml  | 78 +++++++++++--------
 1 file changed, 44 insertions(+), 34 deletions(-)

diff --git a/app/views/admin/versions/_object_desc_and_link.html.haml b/app/views/admin/versions/_object_desc_and_link.html.haml
index 53f5a22d..cc844bd5 100644
--- a/app/views/admin/versions/_object_desc_and_link.html.haml
+++ b/app/views/admin/versions/_object_desc_and_link.html.haml
@@ -1,18 +1,25 @@
+- conference = Conference.find_by(id: version.conference_id)
+- conference_short_title = conference.try(:short_title) || 'deleted_conference'
+- conference_title = conference.try(:title) || 'Deleted Conference'
+
 - case version.item_type
 - when 'UsersRole'
   - users_role = current_or_last_object_state(version.item_type, version.item_id)
   - user = current_or_last_object_state('User', users_role.user_id)
   = 'role'
-  = link_to users_role.role.name, admin_conference_role_path(conference_id: Conference.find(version.conference_id).short_title, id: users_role.role.name)
+  = link_to users_role.role.name, admin_conference_role_path(conference_id: conference_short_title, id: users_role.role.name)
   = version.event == 'create' ? 'to' : 'from'
   = 'user'
 
   = link_to (user.try(:name) || 'deleted user'), admin_user_path(id: users_role.user.id)
 
 - when 'Subscription', 'Registration'
-  = 'conference'
-  = link_to Conference.find(version.conference_id).title,
-          admin_conference_registrations_path(conference_id: Conference.find(version.conference_id).short_title)
+  - if conference
+    = 'conference'
+    = link_to conference_title,
+            admin_conference_registrations_path(conference_id: conference_short_title)
+  - else
+    = "deleted conference with ID #{version.conference_id}"
 
 - when 'Commercial'
   - commercial = current_or_last_object_state(version.item_type, version.item_id)
@@ -25,7 +32,7 @@
     - if commercialable_last_version.item
       event
       =  link_to commercialable.title,
-             admin_conference_program_event_path(conference_id: Conference.find(version.conference_id).short_title, id: commercialable.id)
+             admin_conference_program_event_path(conference_id: conference_short_title, id: commercialable.id)
     - else
       = commercialable.title
 
@@ -33,134 +40,134 @@
     commercial in venue
     - if commercialable_last_version.item
       = link_to commercialable.name,
-            edit_admin_conference_venue_path(conference_id: Conference.find(version.conference_id).short_title,
+            edit_admin_conference_venue_path(conference_id: conference_short_title,
                                                 id: commercialable.id, anchor: 'commercials-content')
     - else
       = commercialable.name
 
   - when 'Conference'
     = link_to 'commercial',
-            admin_conference_commercials_path(conference_id: Conference.find(version.conference_id).short_title)
+            admin_conference_commercials_path(conference_id: conference_short_title)
 
 - when 'EventsRegistration', 'Comment', 'Vote', 'Event'
   = 'event'
   - object = current_or_last_object_state(version.item_type, version.item_id)
   - event_id = object.try(:id) || object.try(:event_id) || object.commentable_id
   = link_to (current_or_last_object_state('Event', event_id).try(:title) || 'deleted event'),
-          admin_conference_program_event_path(conference_id: Conference.find(version.conference_id).short_title, id: event_id)
+          admin_conference_program_event_path(conference_id: conference_short_title, id: event_id)
 
 - when 'Target'
   = 'target'
   - target = current_or_last_object_state(version.item_type, version.item_id)
-  = link_if_alive version, target.to_s, admin_conference_targets_path(conference_id: Conference.find(version.conference_id).short_title)
+  = link_if_alive version, target.to_s, admin_conference_targets_path(conference_id: conference_short_title)
 
 - when 'EventSchedule'
   - event_schedule = current_or_last_object_state(version.item_type, version.item_id)
   event
   = link_to (current_or_last_object_state('Event', event_schedule.event_id).try(:title) || 'deleted event'),
-           admin_conference_program_event_path(conference_id: Conference.find(version.conference_id).short_title, id: event_schedule.event_id)
+           admin_conference_program_event_path(conference_id: conference_short_title, id: event_schedule.event_id)
   in
   =  link_to "Schedule #{event_schedule.schedule_id}",
-            admin_conference_schedule_path(conference_id: Conference.find(version.conference_id).short_title, id: event_schedule.schedule_id)
+            admin_conference_schedule_path(conference_id: conference_short_title, id: event_schedule.schedule_id)
 
 - when 'Schedule'
   = link_if_alive version, "Schedule #{version.item_id}",
-            admin_conference_schedule_path(conference_id: Conference.find(version.conference_id).short_title, id: version.item_id)
+            admin_conference_schedule_path(conference_id: conference_short_title, id: version.item_id)
 
 - when 'Conference'
   = 'conference'
-  = link_to Conference.find(version.conference_id).title,
-          edit_admin_conference_path(id: Conference.find(version.conference_id).short_title)
+  = link_to Conference.find(version.item_id).title,
+          edit_admin_conference_path(id: Conference.find(version.item_id).short_title)
 
 - when 'RegistrationPeriod'
   = link_if_alive version, 'registration period',
-          admin_conference_registration_period_path(conference_id: Conference.find(version.conference_id).short_title)
+          admin_conference_registration_period_path(conference_id: conference_short_title)
 
 - when 'Contact'
   = link_if_alive version, 'contact details',
-          edit_admin_conference_contact_path(conference_id: Conference.find(version.conference_id).short_title)
+          edit_admin_conference_contact_path(conference_id: conference_short_title)
 
 - when 'Program'
   = link_if_alive version, 'program',
-          admin_conference_program_path(conference_id: Conference.find(version.conference_id).short_title)
+          admin_conference_program_path(conference_id: conference_short_title)
 
 - when 'Cfp'
   = link_if_alive version, 'cfp',
-          admin_conference_program_cfp_path(conference_id: Conference.find(version.conference_id).short_title)
+          admin_conference_program_cfp_path(conference_id: conference_short_title)
 
 - when 'Track'
   = 'track'
   - track = current_or_last_object_state(version.item_type, version.item_id)
   = link_if_alive version, track.name,
-          admin_conference_program_track_path(conference_id: Conference.find(version.conference_id).short_title, id: version.item_id)
+          admin_conference_program_track_path(conference_id: conference_short_title, id: version.item_id)
 
 - when 'EventType'
   = 'event type'
   - event_type = current_or_last_object_state(version.item_type, version.item_id)
   = link_if_alive version, event_type.title,
-          admin_conference_program_event_types_path(conference_id: Conference.find(version.conference_id).short_title)
+          admin_conference_program_event_types_path(conference_id: conference_short_title)
 
 - when 'Role'
   = 'role'
   - role = current_or_last_object_state(version.item_type, version.item_id)
   = link_if_alive version, role.name,
-          admin_conference_role_path(conference_id: Conference.find(version.conference_id).short_title, id: role.name)
+          admin_conference_role_path(conference_id: conference_short_title, id: role.name)
 
 - when 'Venue'
   = 'venue'
   - venue = current_or_last_object_state(version.item_type, version.item_id)
   = link_if_alive version, venue.name,
-          admin_conference_venue_path(conference_id: Conference.find(version.conference_id).short_title)
+          admin_conference_venue_path(conference_id: conference_short_title)
 
 - when 'Lodging'
   = 'lodging'
   - lodging = current_or_last_object_state(version.item_type, version.item_id)
   = link_if_alive version, lodging.name,
-          admin_conference_lodgings_path(conference_id: Conference.find(version.conference_id).short_title)
+          admin_conference_lodgings_path(conference_id: conference_short_title)
 
 - when 'Room'
   = 'room'
   - room = current_or_last_object_state(version.item_type, version.item_id)
   = link_if_alive version, room.name,
-          admin_conference_venue_rooms_path(conference_id: Conference.find(version.conference_id).short_title)
+          admin_conference_venue_rooms_path(conference_id: conference_short_title)
 
 - when 'Sponsor'
   = 'sponsor'
   - sponsor = current_or_last_object_state(version.item_type, version.item_id)
   = link_if_alive version, sponsor.name,
-          admin_conference_sponsors_path(conference_id: Conference.find(version.conference_id).short_title)
+          admin_conference_sponsors_path(conference_id: conference_short_title)
 
 - when 'SponsorshipLevel'
   = 'sponsorship level'
   - sponsorship_level = current_or_last_object_state(version.item_type, version.item_id)
   = link_if_alive version, sponsorship_level.title,
-          admin_conference_sponsorship_levels_path(conference_id: Conference.find(version.conference_id).short_title)
+          admin_conference_sponsorship_levels_path(conference_id: conference_short_title)
 
 - when 'Ticket'
   = 'ticket'
   - ticket = current_or_last_object_state(version.item_type, version.item_id)
   = link_if_alive version, ticket.title,
-          admin_conference_ticket_path(conference_id: Conference.find(version.conference_id).short_title, id: version.item_id)
+          admin_conference_ticket_path(conference_id: conference_short_title, id: version.item_id)
 
 - when 'Campaign'
   = 'campaign'
   - campaign = current_or_last_object_state(version.item_type, version.item_id)
   = link_if_alive version, campaign.name,
-          admin_conference_campaigns_path(conference_id: Conference.find(version.conference_id).short_title)
+          admin_conference_campaigns_path(conference_id: conference_short_title)
 
 - when 'DifficultyLevel'
   = 'difficulty level'
   - difficulty_level = current_or_last_object_state(version.item_type, version.item_id)
   = link_if_alive version, difficulty_level.title,
-          admin_conference_program_difficulty_level_path(conference_id: Conference.find(version.conference_id).short_title, id: version.item_id)
+          admin_conference_program_difficulty_level_path(conference_id: conference_short_title, id: version.item_id)
 
 - when 'Splashpage'
   = link_if_alive version, 'splashpage',
-          admin_conference_splashpage_path(conference_id: Conference.find(version.conference_id).short_title)
+          admin_conference_splashpage_path(conference_id: conference_short_title)
 
 - when 'EmailSettings'
   = link_if_alive version, 'email settings',
-          admin_conference_emails_path(conference_id: Conference.find(version.conference_id).short_title)
+          admin_conference_emails_path(conference_id: conference_short_title)
 
 - when 'User'
   - if version.event == 'update'
@@ -168,6 +175,9 @@
     = link_to (current_or_last_object_state('User', version.item_id).try(:name) || 'deleted user'), admin_user_path(id: version.item_id)
 
 - unless %w(Conference Subscription Registration User).include?(version.item_type)
-  = "in conference"
-  = link_to Conference.find(version.conference_id).short_title,
-          edit_admin_conference_path(id: Conference.find(version.conference_id).short_title)
+  - if conference
+    = "in conference"
+    = link_to conference_short_title,
+            edit_admin_conference_path(id: conference_short_title)
+  - else
+    = "in deleted conference with ID #{version.conference_id}"

From 9221f92b1913943345ae6b2a911ab4cba9d5cc80 Mon Sep 17 00:00:00 2001
From: Nishanth Vijayan <nishanththegr8@gmail.com>
Date: Wed, 28 Sep 2016 03:28:47 +0530
Subject: [PATCH 9/9] Use link_to_user instead of explicit link

---
 app/views/admin/versions/_object_desc_and_link.html.haml | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/app/views/admin/versions/_object_desc_and_link.html.haml b/app/views/admin/versions/_object_desc_and_link.html.haml
index cc844bd5..a0f494dd 100644
--- a/app/views/admin/versions/_object_desc_and_link.html.haml
+++ b/app/views/admin/versions/_object_desc_and_link.html.haml
@@ -10,8 +10,7 @@
   = link_to users_role.role.name, admin_conference_role_path(conference_id: conference_short_title, id: users_role.role.name)
   = version.event == 'create' ? 'to' : 'from'
   = 'user'
-
-  = link_to (user.try(:name) || 'deleted user'), admin_user_path(id: users_role.user.id)
+  = link_to_user(users_role.user_id)
 
 - when 'Subscription', 'Registration'
   - if conference