Use ActiveSupport Concern

lib/paper_trail/version.rb

@@ -1,55 +1,62 @@
-module PaperTrail
-  class Version < ::ActiveRecord::Base
-    belongs_to :item, :polymorphic => true
-    validates_presence_of :event
-    attr_accessible :item_type, :item_id, :event, :whodunnit, :object, :object_changes if PaperTrail.active_record_protected_attributes?
+require 'active_support/concern'
 
-    after_create :enforce_version_limit!
+module PaperTrail
+  module VersionConcern
+    extend ActiveSupport::Concern
+    included do
+      belongs_to :item, :polymorphic => true
+      validates_presence_of :event
+      attr_accessible :item_type, :item_id, :event, :whodunnit, :object, :object_changes if PaperTrail.active_record_protected_attributes?
 
-    def self.with_item_keys(item_type, item_id)
-      where :item_type => item_type, :item_id => item_id
+      after_create :enforce_version_limit!
     end
 
-    def self.creates
-      where :event => 'create'
-    end
+    module ClassMethods
+      def with_item_keys(item_type, item_id)
+        where :item_type => item_type, :item_id => item_id
+      end
 
-    def self.updates
-      where :event => 'update'
-    end
+      def creates
+        where :event => 'create'
+      end
 
-    def self.destroys
-      where :event => 'destroy'
-    end
+      def updates
+        where :event => 'update'
+      end
 
-    def self.not_creates
-      where 'event <> ?', 'create'
-    end
+      def destroys
+        where :event => 'destroy'
+      end
 
-    # These methods accept a timestamp or a version and returns other versions that come before or after
-    def self.subsequent(obj)
-      obj = obj.send(PaperTrail.timestamp_field) if obj.is_a?(self)
-      where("#{PaperTrail.timestamp_field} > ?", obj).order("#{PaperTrail.timestamp_field} ASC")
-    end
+      def not_creates
+        where 'event <> ?', 'create'
+      end
 
-    def self.preceding(obj)
-      obj = obj.send(PaperTrail.timestamp_field) if obj.is_a?(self)
-      where("#{PaperTrail.timestamp_field} < ?", obj).order("#{PaperTrail.timestamp_field} DESC")
-    end
+      # These methods accept a timestamp or a version and returns other versions that come before or after
+      def subsequent(obj)
+        obj = obj.send(PaperTrail.timestamp_field) if obj.is_a?(self)
+        where("#{PaperTrail.timestamp_field} > ?", obj).order("#{PaperTrail.timestamp_field} ASC")
+      end
 
-    def self.between(start_time, end_time)
-      where("#{PaperTrail.timestamp_field} > ? AND #{PaperTrail.timestamp_field} < ?", start_time, end_time).
-        order("#{PaperTrail.timestamp_field} ASC")
-    end
+      def preceding(obj)
+        obj = obj.send(PaperTrail.timestamp_field) if obj.is_a?(self)
+        where("#{PaperTrail.timestamp_field} < ?", obj).order("#{PaperTrail.timestamp_field} DESC")
+      end
 
-    # Returns whether the `object` column is using the `json` type supported by PostgreSQL
-    def self.object_col_is_json?
-      @object_col_is_json ||= columns_hash['object'].type == :json
-    end
+      def between(start_time, end_time)
+        where("#{PaperTrail.timestamp_field} > ? AND #{PaperTrail.timestamp_field} < ?", start_time, end_time).
+          order("#{PaperTrail.timestamp_field} ASC")
+      end
+
+      # Returns whether the `object` column is using the `json` type supported by PostgreSQL
+      def object_col_is_json?
+        @object_col_is_json ||= columns_hash['object'].type == :json
+      end
 
-    # Returns whether the `object_changes` column is using the `json` type supported by PostgreSQL
-    def self.object_changes_col_is_json?
-      @object_changes_col_is_json ||= columns_hash['object_changes'].type == :json
+      # Returns whether the `object_changes` column is using the `json` type supported by PostgreSQL
+      def object_changes_col_is_json?
+        @object_changes_col_is_json ||= columns_hash['object_changes'].type == :json
+      end
     end
 
     # Restore the item from this version.
@@ -205,6 +212,9 @@ def enforce_version_limit!
       excess_previous_versions = previous_versions - previous_versions.last(PaperTrail.config.version_limit)
       excess_previous_versions.map(&:destroy)
     end
+  end
 
+  class Version < ::ActiveRecord::Base
+    include VersionConcern
   end
 end

spec/models/version_spec.rb

@@ -1,5 +1,51 @@
 require 'spec_helper'
 
+module Foo
+  class Base < ActiveRecord::Base
+    self.abstract_class = true
+  end
+
+  class Document < Base
+    has_paper_trail :class_name => 'Foo::Version'
+  end
+
+  class Version < Base
+    include PaperTrail::VersionConcern
+  end
+end
+Foo::Base.establish_connection(:adapter => 'sqlite3', :database => File.expand_path('../../../test/dummy/db/test-foo.sqlite3', __FILE__))
+
+module Bar
+  class Base < ActiveRecord::Base
+    self.abstract_class = true
+  end
+
+  class Document < Base
+    has_paper_trail :class_name => 'Bar::Version'
+  end
+
+  class Version < Base
+    include PaperTrail::VersionConcern
+  end
+end
+Bar::Base.establish_connection(:adapter => 'sqlite3', :database => File.expand_path('../../../test/dummy/db/test-bar.sqlite3', __FILE__))
+
+describe PaperTrail::VersionConcern do
+  it 'allows included class to have different connections' do
+    Foo::Version.connection.should_not eq Bar::Version.connection
+  end
+
+  it 'allows custom version class to share connection with superclass' do
+    Foo::Version.connection.should eq Foo::Document.connection
+    Bar::Version.connection.should eq Bar::Document.connection
+  end
+
+  it 'can be used with class_name option' do
+    Foo::Document.version_class_name.should eq 'Foo::Version'
+    Bar::Document.version_class_name.should eq 'Bar::Version'
+  end
+end
+
 describe PaperTrail::Version do
   describe "Attributes" do
     it { should have_db_column(:item_type).of_type(:string) }