code: public function renderStraight(Zend_Navigation_Container $container = null)
      {
          if ($container === null)
          {
              $container = $this->getContainer();
          }
  
          // find deepest active
          if (!$active = $this->findActive($container))
          {
              return '';
          }
  
          $active = $active['page'];
  
          // put the deepest active page last in breadcrumbs
          if ($this->getLinkLast())
          {
              $html = '<li>' . $this->htmlify($active) . '</li>';
          }
          else
          {
              $html = $active->getLabel();
              
              if ($this->getUseTranslator() && $t = $this->getTranslator())
              {
                  $html = $t->translate($html);
              }
              
              $html = '<li class="active">' . $this->view->escape($html) . '</li>';
          }
  
          // walk back to root
          while (($parent = $active->getParent()) != null)
          {
              if ($parent instanceof Zend_Navigation_Page)
              {
                  // prepend crumb to html
                  $html = '<li>' . $this->htmlify($parent) . ' <span class="divider">' . 
                      $this->getSeparator() . '</span></li>' . PHP_EOL . $html;
              }
  
              if ($parent === $container)
              {
                  // at the root of the given container
                  break;
              }
  
              $active = $parent;
          }
  
          return strlen($html) ? $this->getIndent() . '<ul class="breadcrumb">' . $html .  '</ul>' : '';
      }
docs: Renders breadcrumbs based on bootstrap breadcrumbs
  
  @param  Zend_Navigation_Container $container  [optional] container to
  render. Default is to
  render the container
  registered in the helper.
  @return string                                helper output