Extract reifiers/has_and_belongs_to_many

lib/paper_trail/reifier.rb

@@ -1,5 +1,6 @@
 require "paper_trail/attribute_serializers/object_attribute"
 require "paper_trail/reifiers/belongs_to"
+require "paper_trail/reifiers/has_and_belongs_to_many"
 require "paper_trail/reifiers/has_many"
 require "paper_trail/reifiers/has_many_through"
 require "paper_trail/reifiers/has_one"
@@ -102,19 +103,6 @@ module PaperTrail
         (model.attribute_names - attrs.keys).each { |k| attrs[k] = nil }
       end
 
-      # Given a HABTM association `assoc` and an `id`, return a version record
-      # from the point in time identified by `transaction_id` or `version_at`.
-      # @api private
-      def load_version_for_habtm(assoc, id, transaction_id, version_at)
-        assoc.klass.paper_trail.version_class.
-          where("item_type = ?", assoc.klass.name).
-          where("item_id = ?", id).
-          where("created_at >= ? OR transaction_id = ?", version_at, transaction_id).
-          order("id").
-          limit(1).
-          first
-      end
-
       # Reify onto `model` an attribute named `k` with value `v` from `version`.
       #
       # `ObjectAttribute#deserialize` will return the mapped enum value and in
@@ -200,47 +188,13 @@ module PaperTrail
         end
       end
 
-      # Reify a single HABTM association of `model`.
-      # @api private
-      def reify_habtm_association(assoc, model, options, papertrail_enabled, transaction_id)
-        version_ids = PaperTrail::VersionAssociation.
-          where("foreign_key_name = ?", assoc.name).
-          where("version_id = ?", transaction_id).
-          pluck(:foreign_key_id)
-
-        model.send(assoc.name).proxy_association.target =
-          version_ids.map do |id|
-            if papertrail_enabled
-              version = load_version_for_habtm(
-                assoc,
-                id,
-                transaction_id,
-                options[:version_at]
-              )
-              if version
-                next version.reify(
-                  options.merge(
-                    has_many: false,
-                    has_one: false,
-                    belongs_to: false,
-                    has_and_belongs_to_many: false
-                  )
-                )
-              end
-            end
-            assoc.klass.where(assoc.klass.primary_key => id).first
-          end
-      end
-
       # Reify all HABTM associations of `model`.
       # @api private
       def reify_habtm_associations(transaction_id, model, options = {})
         model.class.reflect_on_all_associations(:has_and_belongs_to_many).each do |assoc|
-          papertrail_enabled = assoc.klass.paper_trail.enabled?
-          next unless
-            model.class.paper_trail_save_join_tables.include?(assoc.name) ||
-                papertrail_enabled
-          reify_habtm_association(assoc, model, options, papertrail_enabled, transaction_id)
+          pt_enabled = assoc.klass.paper_trail.enabled?
+          next unless model.class.paper_trail_save_join_tables.include?(assoc.name) || pt_enabled
+          Reifiers::HasAndBelongsToMany.reify(pt_enabled, assoc, model, options, transaction_id)
         end
       end
 

lib/paper_trail/reifiers/has_and_belongs_to_many.rb

@@ -0,0 +1,50 @@
+module PaperTrail
+  module Reifiers
+    # Reify a single HABTM association of `model`.
+    # @api private
+    module HasAndBelongsToMany
+      class << self
+        # @api private
+        def reify(pt_enabled, assoc, model, options, transaction_id)
+          version_ids = ::PaperTrail::VersionAssociation.
+            where("foreign_key_name = ?", assoc.name).
+            where("version_id = ?", transaction_id).
+            pluck(:foreign_key_id)
+
+          model.send(assoc.name).proxy_association.target =
+            version_ids.map do |id|
+              if pt_enabled
+                version = load_version(assoc, id, transaction_id, options[:version_at])
+                if version
+                  next version.reify(
+                    options.merge(
+                      has_many: false,
+                      has_one: false,
+                      belongs_to: false,
+                      has_and_belongs_to_many: false
+                    )
+                  )
+                end
+              end
+              assoc.klass.where(assoc.klass.primary_key => id).first
+            end
+        end
+
+        private
+
+        # Given a HABTM association `assoc` and an `id`, return a version record
+        # from the point in time identified by `transaction_id` or `version_at`.
+        # @api private
+        def load_version(assoc, id, transaction_id, version_at)
+          assoc.klass.paper_trail.version_class.
+            where("item_type = ?", assoc.klass.name).
+            where("item_id = ?", id).
+            where("created_at >= ? OR transaction_id = ?", version_at, transaction_id).
+            order("id").
+            limit(1).
+            first
+        end
+      end
+    end
+  end
+end