postgis/posgresql composite primary key patch

gistfile1.rb

module CompositePrimaryKeys
  class CompositeKeys
    def to_sym
      join('_').to_sym
    end
  end
  
  module ActiveRecord
    module Persistence
      def update_record(attribute_names = @attributes.keys)
        return super(attribute_names) unless composite?
        
        klass = self.class
        
        if should_record_timestamps?
          current_time = current_time_from_proper_timezone

          timestamp_attributes_for_update_in_model.each do |column|
            column = column.to_s
            next if attribute_changed?(column)
            write_attribute(column, current_time)
          end
        end
        
        attributes_with_values = arel_attributes_with_values_for_update(attribute_names)
        return 0 if attributes_with_values.empty?
        
        column_hash = klass.connection.schema_cache.columns_hash klass.table_name
        db_columns_with_values = attributes_with_values.map { |attr,value|
          real_column = column_hash[attr.name]
          [real_column, value]
        }
        bind_attrs = attributes_with_values.dup
        bind_attrs.keys.each_with_index do |column, i|
          real_column = db_columns_with_values[i].first
          bind_attrs[column] = klass.connection.substitute_at(real_column, i)
        end
        
        if !can_change_primary_key? and primary_key_changed?
          raise ActiveRecord::CompositeKeyError, "Cannot update primary key values without ActiveModel::Dirty"
        elsif primary_key_changed?
          stmt = klass.unscoped.where(primary_key_was).arel.compile_update(bind_attrs)
        else
          stmt = klass.unscoped.where(ids_hash).arel.compile_update(bind_attrs)
        end
        
        klass.connection.update stmt.to_sql, 'SQL', db_columns_with_values
      end
    end
  end
end

module ActiveRecord
  module Persistence
    
    private
    
    alias_method :original_create_record, :create_record
    
    def create_record(attribute_names = @attributes.keys)
      return(original_create_record(attribute_names)) unless composite?
      
      attributes_values = arel_attributes_with_values_for_create(attribute_names)
      new_id = self.class.unscoped.insert attributes_values
      
      # uncomment for rails > 4.0.0
      #
      #default_function = self.class.columns_hash[self.class.primary_keys.first].default_function
      #
      #if default_function && default_function =~ /nextval/
      #  self[self.class.primary_keys.first] ||= new_id
      #elsif self.class.primary_key
      #  self.id ||= new_id
      #end
      
      self[self.class.primary_keys.first] = new_id if self.class.primary_keys.is_a?(Array)
      self.id ||= new_id
      
      @new_record = false
      id
    end
  end
end


module ActiveRecord::Associations::Builder
  class BelongsTo < SingularAssociation
    def add_touch_callbacks(reflection)
      mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1
        def belongs_to_touch_after_save_or_destroy_for_#{name}
          foreign_key_field = #{reflection.foreign_key.inspect}
          
          if foreign_key_field.is_a?(Array)
            old_foreign_id = foreign_key_field.map{ |field| attribute_was(field) }
          else
            old_foreign_id = attribute_was(foreign_key_field)
          end
          
          if old_foreign_id
            klass      = association(#{name.inspect}).klass
            old_record = klass.find_by(klass.primary_key => old_foreign_id)

            if old_record
              old_record.touch #{options[:touch].inspect if options[:touch] != true}
            end
          end

          record = #{name}
          unless record.nil? || record.new_record?
            record.touch #{options[:touch].inspect if options[:touch] != true}
          end
        end
      CODE

      model.after_save    "belongs_to_touch_after_save_or_destroy_for_#{name}"
      model.after_touch   "belongs_to_touch_after_save_or_destroy_for_#{name}"
      model.after_destroy "belongs_to_touch_after_save_or_destroy_for_#{name}"
    end
  end
end