Generating the next migration number

install_generator.rb

# This is based on the implementation in ActiveRecord (I believe). I've added the %3N (and further padded the string format) to include milliseconds since multiple migrations will often be run in an engine's installer.


      def self.next_migration_number( dirname )
        next_migration_number = current_migration_number(dirname) + 1
        if ActiveRecord::Base.timestamped_migrations
          [Time.now.utc.strftime("%Y%m%d%H%M%S%6N"), "%.20d" % next_migration_number].max
        else
          "%.3d" % next_migration_number
        end
      end