Add a HasAssociation module for common code for has_* associations

8 files changed, 69 insertions, 61 deletions

diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 1056c51a3d..b49cf8de95 100644
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -120,6 +120,8 @@ module ActiveRecord
     # So there is no need to eager load them.
     autoload :AssociationCollection, 'active_record/associations/association_collection'
     autoload :AssociationProxy, 'active_record/associations/association_proxy'
+    autoload :HasAssociation, 'active_record/associations/has_association'
+    autoload :ThroughAssociation, 'active_record/associations/through_association'
     autoload :BelongsToAssociation, 'active_record/associations/belongs_to_association'
     autoload :BelongsToPolymorphicAssociation, 'active_record/associations/belongs_to_polymorphic_association'
     autoload :HasAndBelongsToManyAssociation, 'active_record/associations/has_and_belongs_to_many_association'
diff --git a/activerecord/lib/active_record/associations/association_collection.rb b/activerecord/lib/active_record/associations/association_collection.rb
index c9f9c925b0..86cc17394c 100644
--- a/activerecord/lib/active_record/associations/association_collection.rb
+++ b/activerecord/lib/active_record/associations/association_collection.rb
@@ -18,6 +18,8 @@ module ActiveRecord
     # If you need to work on all current children, new and existing records,
     # +load_target+ and the +loaded+ flag are your friends.
     class AssociationCollection < AssociationProxy #:nodoc:
+      include HasAssociation
+
       delegate :group, :order, :limit, :joins, :where, :preload, :eager_load, :includes, :from, :lock, :readonly, :having, :to => :scoped
 
       def select(select = nil)
diff --git a/activerecord/lib/active_record/associations/association_proxy.rb b/activerecord/lib/active_record/associations/association_proxy.rb
index c7b171b41d..b60aa33c98 100644
--- a/activerecord/lib/active_record/associations/association_proxy.rb
+++ b/activerecord/lib/active_record/associations/association_proxy.rb
@@ -4,17 +4,17 @@ module ActiveRecord
   module Associations
     # = Active Record Associations
     #
-    # This is the root class of all association proxies:
+    # This is the root class of all association proxies ('+ Foo' signifies an included module Foo):
     #
     #   AssociationProxy
     #     BelongsToAssociation
-    #       HasOneAssociation
     #     BelongsToPolymorphicAssociation
-    #     AssociationCollection
+    #     AssociationCollection + HasAssociation
     #       HasAndBelongsToManyAssociation
     #       HasManyAssociation
-    #         HasManyThroughAssociation
-    #            HasOneThroughAssociation
+    #         HasManyThroughAssociation + ThroughAssociation
+    #     HasOneAssociation + HasAssociation
+    #       HasOneThroughAssociation + ThroughAssociation
     #
     # Association proxies in Active Record are middlemen between the object that
     # holds the association, known as the <tt>@owner</tt>, and the actual associated
@@ -176,43 +176,6 @@ module ActiveRecord
           @reflection.klass.send(:sanitize_sql, sql, table_name)
         end
 
-        # Sets the owner attributes on the given record
-        # Note: does not really make sense for belongs_to associations, but this method is not
-        #       used by belongs_to
-        def set_owner_attributes(record)
-          if @owner.persisted?
-            construct_owner_attributes.each { |key, value| record[key] = value }
-          end
-        end
-
-        # Returns a has linking the owner to the association represented by the reflection
-        def construct_owner_attributes(reflection = @reflection)
-          attributes = {}
-          if reflection.macro == :belongs_to
-            attributes[reflection.association_primary_key] = @owner.send(reflection.primary_key_name)
-          else
-            attributes[reflection.primary_key_name] = @owner.send(reflection.active_record_primary_key)
-
-            if reflection.options[:as]
-              attributes["#{reflection.options[:as]}_type"] = @owner.class.base_class.name
-            end
-          end
-          attributes
-        end
-
-        # Builds an array of arel nodes from the owner attributes hash
-        def construct_owner_conditions(table = aliased_table, reflection = @reflection)
-          construct_owner_attributes(reflection).map do |attr, value|
-            table[attr].eq(value)
-          end
-        end
-
-        def construct_conditions
-          conditions = construct_owner_conditions
-          conditions << Arel.sql(sql_conditions) if sql_conditions
-          aliased_table.create_and(conditions)
-        end
-
         # Merges into +options+ the ones coming from the reflection.
         def merge_options_from_reflection!(options)
           options.reverse_merge!(
@@ -312,18 +275,6 @@ module ActiveRecord
           end
         end
 
-        if RUBY_VERSION < '1.9.2'
-          # Array#flatten has problems with recursive arrays before Ruby 1.9.2.
-          # Going one level deeper solves the majority of the problems.
-          def flatten_deeper(array)
-            array.collect { |element| (element.respond_to?(:flatten) && !element.is_a?(Hash)) ? element.flatten : element }.flatten
-          end
-        else
-          def flatten_deeper(array)
-            array.flatten
-          end
-        end
-
         # Returns the ID of the owner, quoted if needed.
         def owner_quoted_id
           @owner.quoted_id
diff --git a/activerecord/lib/active_record/associations/has_association.rb b/activerecord/lib/active_record/associations/has_association.rb
new file mode 100644
index 0000000000..4407e2ea9a
--- /dev/null
+++ b/activerecord/lib/active_record/associations/has_association.rb
@@ -0,0 +1,54 @@
+module ActiveRecord
+  module Associations
+    # Included in all has_* associations (i.e. everything except belongs_to)
+    module HasAssociation #:nodoc:
+      protected
+        # Sets the owner attributes on the given record
+        def set_owner_attributes(record)
+          if @owner.persisted?
+            construct_owner_attributes.each { |key, value| record[key] = value }
+          end
+        end
+
+        # Returns a hash linking the owner to the association represented by the reflection
+        def construct_owner_attributes(reflection = @reflection)
+          attributes = {}
+          if reflection.macro == :belongs_to
+            attributes[reflection.association_primary_key] = @owner.send(reflection.primary_key_name)
+          else
+            attributes[reflection.primary_key_name] = @owner.send(reflection.active_record_primary_key)
+
+            if reflection.options[:as]
+              attributes["#{reflection.options[:as]}_type"] = @owner.class.base_class.name
+            end
+          end
+          attributes
+        end
+
+        # Builds an array of arel nodes from the owner attributes hash
+        def construct_owner_conditions(table = aliased_table, reflection = @reflection)
+          construct_owner_attributes(reflection).map do |attr, value|
+            table[attr].eq(value)
+          end
+        end
+
+        def construct_conditions
+          conditions = construct_owner_conditions
+          conditions << Arel.sql(sql_conditions) if sql_conditions
+          aliased_table.create_and(conditions)
+        end
+
+        if RUBY_VERSION < '1.9.2'
+          # Array#flatten has problems with recursive arrays before Ruby 1.9.2.
+          # Going one level deeper solves the majority of the problems.
+          def flatten_deeper(array)
+            array.collect { |element| (element.respond_to?(:flatten) && !element.is_a?(Hash)) ? element.flatten : element }.flatten
+          end
+        else
+          def flatten_deeper(array)
+            array.flatten
+          end
+        end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb
index 4dabfe2ea3..8569a2f004 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -1,11 +1,10 @@
-require "active_record/associations/through_association_scope"
 require 'active_support/core_ext/object/blank'
 
 module ActiveRecord
   # = Active Record Has Many Through Association
   module Associations
     class HasManyThroughAssociation < HasManyAssociation #:nodoc:
-      include ThroughAssociationScope
+      include ThroughAssociation
 
       alias_method :new, :build
 
diff --git a/activerecord/lib/active_record/associations/has_one_association.rb b/activerecord/lib/active_record/associations/has_one_association.rb
index 654157d998..ca0828ea7b 100644
--- a/activerecord/lib/active_record/associations/has_one_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_association.rb
@@ -2,6 +2,8 @@ module ActiveRecord
   # = Active Record Belongs To Has One Association
   module Associations
     class HasOneAssociation < AssociationProxy #:nodoc:
+      include HasAssociation
+
       def create(attrs = {}, replace_existing = true)
         new_record(replace_existing) do |reflection|
           attrs = merge_with_conditions(attrs)
diff --git a/activerecord/lib/active_record/associations/has_one_through_association.rb b/activerecord/lib/active_record/associations/has_one_through_association.rb
index 8c8c9fbe5d..c9ae930e93 100644
--- a/activerecord/lib/active_record/associations/has_one_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_through_association.rb
@@ -1,10 +1,8 @@
-require "active_record/associations/through_association_scope"
-
 module ActiveRecord
   # = Active Record Has One Through Association
   module Associations
     class HasOneThroughAssociation < HasOneAssociation
-      include ThroughAssociationScope
+      include ThroughAssociation
 
       def replace(new_value)
         create_through_record(new_value)
diff --git a/activerecord/lib/active_record/associations/through_association_scope.rb b/activerecord/lib/active_record/associations/through_association.rb
index 1abeb178ff..57718285f8 100644
--- a/activerecord/lib/active_record/associations/through_association_scope.rb
+++ b/activerecord/lib/active_record/associations/through_association.rb
@@ -1,7 +1,7 @@
 module ActiveRecord
-  # = Active Record Through Association Scope
+  # = Active Record Through Association
   module Associations
-    module ThroughAssociationScope
+    module ThroughAssociation
 
       def scoped
         with_scope(@scope) do