HasOneThroughAssociation still shouldn't derive from HasManyThroughAssociation.

[#1642 state:committed]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

1 files changed, 147 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/associations/through_association_scope.rb b/activerecord/lib/active_record/associations/through_association_scope.rb
new file mode 100644
index 0000000000..7661c50039
--- /dev/null
+++ b/activerecord/lib/active_record/associations/through_association_scope.rb
@@ -0,0 +1,147 @@
+module ActiveRecord
+  module Associations
+    module ThroughAssociationScope
+
+      protected
+
+      def construct_scope
+        { :create => construct_owner_attributes(@reflection),
+          :find   => { :from        => construct_from,
+                       :conditions  => construct_conditions,
+                       :joins       => construct_joins,
+                       :include     => @reflection.options[:include] || @reflection.source_reflection.options[:include],
+                       :select      => construct_select,
+                       :order       => @reflection.options[:order],
+                       :limit       => @reflection.options[:limit],
+                       :readonly    => @reflection.options[:readonly],
+           } }
+      end
+
+      # Build SQL conditions from attributes, qualified by table name.
+      def construct_conditions
+        table_name = @reflection.through_reflection.quoted_table_name
+        conditions = construct_quoted_owner_attributes(@reflection.through_reflection).map do |attr, value|
+          "#{table_name}.#{attr} = #{value}"
+        end
+        conditions << sql_conditions if sql_conditions
+        "(" + conditions.join(') AND (') + ")"
+      end
+
+      # Associate attributes pointing to owner, quoted.
+      def construct_quoted_owner_attributes(reflection)
+        if as = reflection.options[:as]
+          { "#{as}_id" => owner_quoted_id,
+            "#{as}_type" => reflection.klass.quote_value(
+              @owner.class.base_class.name.to_s,
+              reflection.klass.columns_hash["#{as}_type"]) }
+        elsif reflection.macro == :belongs_to
+          { reflection.klass.primary_key => @owner[reflection.primary_key_name] }
+        else
+          { reflection.primary_key_name => owner_quoted_id }
+        end
+      end
+
+      def construct_from
+        @reflection.quoted_table_name
+      end
+
+      def construct_select(custom_select = nil)
+        distinct = "DISTINCT " if @reflection.options[:uniq]
+        selected = custom_select || @reflection.options[:select] || "#{distinct}#{@reflection.quoted_table_name}.*"
+      end
+
+      def construct_joins(custom_joins = nil)
+        polymorphic_join = nil
+        if @reflection.source_reflection.macro == :belongs_to
+          reflection_primary_key = @reflection.klass.primary_key
+          source_primary_key     = @reflection.source_reflection.primary_key_name
+          if @reflection.options[:source_type]
+            polymorphic_join = "AND %s.%s = %s" % [
+              @reflection.through_reflection.quoted_table_name, "#{@reflection.source_reflection.options[:foreign_type]}",
+              @owner.class.quote_value(@reflection.options[:source_type])
+            ]
+          end
+        else
+          reflection_primary_key = @reflection.source_reflection.primary_key_name
+          source_primary_key     = @reflection.through_reflection.klass.primary_key
+          if @reflection.source_reflection.options[:as]
+            polymorphic_join = "AND %s.%s = %s" % [
+              @reflection.quoted_table_name, "#{@reflection.source_reflection.options[:as]}_type",
+              @owner.class.quote_value(@reflection.through_reflection.klass.name)
+            ]
+          end
+        end
+
+        "INNER JOIN %s ON %s.%s = %s.%s %s #{@reflection.options[:joins]} #{custom_joins}" % [
+          @reflection.through_reflection.quoted_table_name,
+          @reflection.quoted_table_name, reflection_primary_key,
+          @reflection.through_reflection.quoted_table_name, source_primary_key,
+          polymorphic_join
+        ]
+      end
+
+      # Construct attributes for associate pointing to owner.
+      def construct_owner_attributes(reflection)
+        if as = reflection.options[:as]
+          { "#{as}_id" => @owner.id,
+            "#{as}_type" => @owner.class.base_class.name.to_s }
+        else
+          { reflection.primary_key_name => @owner.id }
+        end
+      end
+
+      # Construct attributes for :through pointing to owner and associate.
+      def construct_join_attributes(associate)
+        # TODO: revist this to allow it for deletion, supposing dependent option is supported
+        raise ActiveRecord::HasManyThroughCantAssociateThroughHasManyReflection.new(@owner, @reflection) if @reflection.source_reflection.macro == :has_many
+        join_attributes = construct_owner_attributes(@reflection.through_reflection).merge(@reflection.source_reflection.primary_key_name => associate.id)
+        if @reflection.options[:source_type]
+          join_attributes.merge!(@reflection.source_reflection.options[:foreign_type] => associate.class.base_class.name.to_s)
+        end
+        join_attributes
+      end
+
+      def conditions
+        @conditions = build_conditions unless defined?(@conditions)
+        @conditions
+      end
+
+      def build_conditions
+        association_conditions = @reflection.options[:conditions]
+        through_conditions = build_through_conditions
+        source_conditions = @reflection.source_reflection.options[:conditions]
+        uses_sti = !@reflection.through_reflection.klass.descends_from_active_record?
+
+        if association_conditions || through_conditions || source_conditions || uses_sti
+          all = []
+
+          [association_conditions, source_conditions].each do |conditions|
+            all << interpolate_sql(sanitize_sql(conditions)) if conditions
+          end
+
+          all << through_conditions  if through_conditions
+          all << build_sti_condition if uses_sti
+
+          all.map { |sql| "(#{sql})" } * ' AND '
+        end
+      end
+
+      def build_through_conditions
+        conditions = @reflection.through_reflection.options[:conditions]
+        if conditions.is_a?(Hash)
+          interpolate_sql(sanitize_sql(conditions)).gsub(
+            @reflection.quoted_table_name,
+            @reflection.through_reflection.quoted_table_name)
+        elsif conditions
+          interpolate_sql(sanitize_sql(conditions))
+        end
+      end
+
+      def build_sti_condition
+        @reflection.through_reflection.klass.send(:type_condition)
+      end
+
+      alias_method :sql_conditions, :conditions
+    end
+  end
+end