[HelpPages] Fix json & move modaction logging (#700)

* Fix #492 (json error when no help pages exist)
* Move modactions into class

app/controllers/help_controller.rb

@@ -3,8 +3,7 @@
 class HelpController < ApplicationController
   respond_to :html, :json
   helper :wiki_pages
-  before_action :admin_only, only: [:new, :create, :edit,
-                                    :update, :destroy]
+  before_action :admin_only, except: %i[index show]
 
   def show
     if params[:id] =~ /\A\d+\Z/
@@ -18,16 +17,14 @@ class HelpController < ApplicationController
           redirect_to help_pages_path
         end
       end
-      format.json do
-        raise ActiveRecord::RecordNotFound if @help.blank?
-        render json: @help
-      end
     end
   end
 
   def index
     @help_pages = HelpPage.help_index
-    respond_with(@help_pages)
+    respond_with(@help_pages) do |format|
+      format.json { render json: @help_pages.to_json }
+    end
   end
 
   def new
@@ -42,27 +39,20 @@ class HelpController < ApplicationController
 
   def create
     @help = HelpPage.create(help_params)
-    if @help.valid?
-      flash[:notice] = 'Help page created'
-      ModAction.log(:help_create, {name: @help.name, wiki_page: @help.wiki_page})
-    end
+    flash[:notice] = "Help page created" if @help.valid?
     respond_with(@help)
   end
 
   def update
     @help = HelpPage.find(params[:id])
     @help.update(help_params)
-    if @help.valid?
-      flash[:notice] = "Help entry updated"
-      ModAction.log(:help_update,{name: @help.name, wiki_page: @help.wiki_page})
-    end
+    flash[:notice] = "Help entry updated" if @help.valid?
     respond_with(@help)
   end
 
   def destroy
     @help = HelpPage.find(params[:id])
     @help.destroy
-    ModAction.log(:help_delete, {name: @help.name, wiki_page: @help.wiki_page})
     respond_with(@help)
   end
 

app/models/help_page.rb

@@ -5,7 +5,10 @@ class HelpPage < ApplicationRecord
   validates :wiki_page, :name, presence: true
   normalizes :name, with: ->(name) { name.downcase.strip.tr(" ", "_") }
   validate :wiki_page_exists
+  after_create :log_create
+  after_update :log_update
   after_destroy :invalidate_cache
+  after_destroy :log_destroy
   after_save :invalidate_cache
   belongs_to :wiki, class_name: "WikiPage", foreign_key: "wiki_page", primary_key: "title"
 
@@ -37,4 +40,20 @@ class HelpPage < ApplicationRecord
   def self.help_index
     Cache.fetch("help_index", expires_in: 12.hours) { HelpPage.all.sort_by(&:pretty_title) }
   end
+
+  module LogMethods
+    def log_create
+      ModAction.log(:help_create, { name: name, wiki_page: wiki_page })
+    end
+
+    def log_update
+      ModAction.log(:help_update, { name: name, wiki_page: wiki_page })
+    end
+
+    def log_destroy
+      ModAction.log(:help_delete, { name: name, wiki_page: wiki_page })
+    end
+  end
+
+  include LogMethods
 end