Module: Positionable

Extended by:
ActiveSupport::Concern
Included in:
Category
Defined in:
app/models/concerns/positionable.rb

Instance Method Summary collapse

Instance Method Details

#move_to(position_arg) ⇒ Object 



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# File 'app/models/concerns/positionable.rb', line 8

def move_to(position_arg)
  position = [[position_arg, 0].max, self.class.count - 1].min

  if self.position.nil? || position > (self.position)
    DB.exec "
    UPDATE #{self.class.table_name}
    SET position = position - 1
    WHERE position > :current_position and position <= :new_position",
            current_position: self.position,
            new_position: position
  elsif position < self.position
    DB.exec "
    UPDATE #{self.class.table_name}
    SET position = position + 1
    WHERE position >= :new_position and position < :current_position",
            current_position: self.position,
            new_position: position
  else
    # Not moving to a new position
    return
  end

  DB.exec "
  UPDATE #{self.class.table_name}
  SET position = :position
  WHERE id = :id",
          id: id,
          position: position

  self.position = position
end