new_contents: 
  class Selectors(object):
      def setup_bot(self, settings, spec, items, extractors):
          self.selectors = {} # { item_type: { field_name: {..} }
  
          for template in spec['templates']:
              selectors = self.selectors.setdefault(template['scrapes'], {})
              selectors.update(template.get('selectors', {}))
  
      def process_item(self, item, response):
          item_type = item.get('_type', '')
          selectors = self.selectors.get(item_type)
          if not selectors:
              return
  
          for field, selector_data in selectors.iteritems():
              selector = selector_data['selector']
              selector_type = selector_data['type']
              if selector_type == 'css':
                  item[field] = response.css(selector).xpath('./text()').extract()
              elif selector_type == 'xpath':
                  item[field] = response.xpath(selector).extract()
              else:
                  msg = 'Selector type not implemented: {}'.format(selector_type)
                  raise Exception(msg)
  
  __all__ = [Selectors]
  
  
subject: Add selectors plugin