class ActiveRecord::Base
  before_validation :strip_text_attributes
  
 private
  def strip_text_attributes
    each_text_attribute do |attribute, value|
      self[attribute] = value.strip
    end
  end
  
  def each_text_attribute
    self.class.columns.select(&:text?).map(&:name).each do |attribute|
      value = self[attribute]
      yield attribute, value if value.is_a?(String)
    end
  end
end