main.rb

c = XmlImport.new("path", CockatriceXmlParser).process!
    
c.each { |card_attributes| Card.create!(card_attributes, :without_protection => true) }

parser.rb

class CockatriceXmlParser
  def initialize(node)
    @card_data = node
  end

  def name
    @card_data.search("name").text 
  end
  
  def image
    @card_data.search("set").attribute("picURL").text 
  end

  def set       
    @card_data.search("set").text
  end

  def color     
    @card_data.search("color").text
  end

  def manacost  
    @card_data.search("manacost").text
  end

  def card_type 
    @card_data.search("type").text
  end

  def text      
    @card_data.search("text").text
  end
  
  def loyalty   
    @card_data.search("loyalty").text
  end

  def power      
    @card_data.search("pt").split("/").first
  end
  
  def toughness      
    @card_data.search("pt").split("/").last
  end
end

xmlimport.rb

class XmlImport
  def initialize(path, parser)
    @path = path
    @parser = parser
  end

  def process!
    repository.map do |card|
      card_data = @parser.new(card)

      {
        :name      => card_data.name,
        :image     => card_data.image,
        :set       => card_data.set,
        :color     => card_data.color,
        :manacost  => card_data.manacost,
        :card_type => card_data.card_type,
        :text      => card_data.text,
        :loyalty   => card_data.loyalty,
        :power     => card_data.power,
        :toughness => card_data.toughness
      } 
    end
  end

  def repository
    Nokogiri::XML(File.open(@path)).search("card")
  end
end