next_chain_scope

# File activerecord/lib/active_record/associations/association_scope.rb, line 115
      def next_chain_scope(scope, table, reflection, tracker, assoc_klass, foreign_table, next_reflection)
        join_keys = reflection.join_keys(assoc_klass)
        key = join_keys.key
        foreign_key = join_keys.foreign_key

        constraint = table[key].eq(foreign_table[foreign_key])

        if reflection.type
          value    = next_reflection.klass.base_class.name
          bind_val = bind scope, table.table_name, reflection.type, value, tracker
          scope    = scope.where(table[reflection.type].eq(bind_val))
        end

        scope = scope.joins(join(foreign_table, constraint))
      end