Add folders to the documents plugin

db/migrate/20171105000000_add_parent_to_document.foodsoft_documents_engine.rb

@@ -0,0 +1,5 @@
+class AddParentToDocument < ActiveRecord::Migration
+  def change
+    add_reference :documents, :parent, index: true
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20171002000000) do
+ActiveRecord::Schema.define(version: 20171110000000) do
 
   create_table "article_categories", force: :cascade do |t|
     t.string "name",        limit: 255, default: "", null: false
@@ -83,8 +83,11 @@ ActiveRecord::Schema.define(version: 20171002000000) do
     t.integer  "created_by_user_id"
     t.datetime "created_at"
     t.datetime "updated_at"
+    t.integer  "parent_id"
   end
 
+  add_index "documents", ["parent_id"], name: "index_documents_on_parent_id", using: :btree
+
   create_table "financial_link", force: :cascade do |t|
     t.text "note"
   end