paper_trail gemを利用して更新履歴を保存する

github.com

Gemfileにgemを追加して bundle install

gem 'paper_trail'

generaterでpaper_trail用のDBを作るマイグレーションファイルを作成して db:migrateを実行

bundle exec rails generate paper_trail:install 
bundle exec rake db:migrate

作られるマイグレーションファイルはこんな感じ

# This migration creates the `versions` table, the only schema PT requires.
# All other migrations PT provides are optional.
class CreateVersions < ActiveRecord::Migration[6.0]

  # 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.bigint   :item_id,   null: false
      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

履歴管理したいモデルに has_paper_trail を追加

class Widget < ActiveRecord::Base
  has_paper_trail
end

更新者をセットするようにapplication_controllerに追記 deviseなど使っていてcurrent_userが存在すれば以下だけでよい

class ApplicationController
  before_action :set_paper_trail_whodunnit
end

コレでpaper_trailのセットアップは完了 次に紐づく関連テーブルの履歴管理もしたいのでpaper_trail-association_trackingを導入する

github.com

Gemfileにgemを追加して bundle install

gem 'paper_trail-association_tracking'

generaterでpaper_trail用のDBを作るマイグレーションファイルを作成して db:migrateを実行

rails generate paper_trail_association_tracking:install
bundle exec rake db:migrate

作られるマイグレーションファイルはこんな感じ

# This migration and AddTransactionIdColumnToVersions provide the necessary
# schema for tracking associations.
class CreateVersionAssociations < ActiveRecord::Migration[6.0]
  def self.up
    create_table :version_associations do |t|
      t.integer  :version_id
      t.string   :foreign_key_name, null: false
      t.integer  :foreign_key_id
      t.string   :foreign_type
    end
    add_index :version_associations, [:version_id]
    add_index :version_associations,
      %i(foreign_key_name foreign_key_id foreign_type),
      name: "index_version_associations_on_foreign_key"
  end

  def self.down
    remove_index :version_associations, [:version_id]
    remove_index :version_associations,
      name: "index_version_associations_on_foreign_key"
    drop_table :version_associations
  end
end

# This migration and CreateVersionAssociations provide the necessary
# schema for tracking associations.
class AddTransactionIdColumnToVersions < ActiveRecord::Migration[6.0]
  def self.up
    add_column :versions, :transaction_id, :integer
    add_index :versions, [:transaction_id]
  end

  def self.down
    remove_index :versions, [:transaction_id]
    remove_column :versions, :transaction_id
  end
end

生成されたinitializerを更新 config/initializers/paper_trail.rb

PaperTrail.config.track_associations = true