method

inverse

v3.2.8 - Show latest stable - Class: ActiveRecord::Migration::CommandRecorder

inverse()

public

Returns a list that represents commands that are the inverse of the commands stored in commands. For example:

recorder.record(:rename_table, [:old, :new])
recorder.inverse # => [:rename_table, [:new, :old]]

This method will raise an IrreversibleMigration exception if it cannot invert the commands.

# File activerecord/lib/active_record/migration/command_recorder.rb, line 39
      def inverse
        @commands.reverse.map { |name, args|
          method = :"invert_#{name}"
          raise IrreversibleMigration unless respond_to?(method, true)
          send(method, args)
        }
      end

inverse

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