Magento - 由于自定义特别优惠类别导致的AJAX错误

Question

我已将此代码添加到Custom Design＆gt;特别优惠类别的自定义布局更新：

<reference name="content">
<remove name="product_list"/>
<block type="catalog/product_sale" name="product_sale" alias="sale" template="catalog/product/list.phtml">
<block type="catalog/product_list_toolbar" name="product_list_toolbar" template="catalog/product/list/toolbar.phtml">
<block type="page/html_pager" name="product_list_toolbar_pager"/>
</block>
<action method="setLimit"><limit>9</limit></action>
<action method="setColumnCount"><columns>3</columns></action>
<action method="setToolbarBlockName"><name>product_list_toolbar</name></action>
<action method="addPriceBlockType">
<type>bundle</type>
<block>bundle/catalog_product_price</block>
<template>bundle/catalog/product/price.phtml</template>
</action>
</block>
</reference>
<reference name="product_list_toolbar">
<action method="setDefaultGridPerPage">
<limit>9</limit>
</action>
</reference>

这使特殊优惠类别从以下php文件中读取：

/app/code/local/Mage/Catalog/Block/Product/Sale.php

其中包含以下内容：

<?php

class Mage_Catalog_Block_Product_Sale extends Mage_Catalog_Block_Product_List
{

    //public $_collection;  

    public function getProductsLimit() 
    { 
        if ($this->getData('limit')) {
            return intval($this->getData('limit'));
        } else {
            return 32;
        }
    }

    public function __construct()
    {
        parent::__construct();
        $collection = $this->_getProductCollection();
        $this->setCollection($collection);
    }






     protected function _getProductCollection()  
     {  
                $page = Mage::getBlockSingleton('page/html_pager')->getCurrentPage();
                date_default_timezone_set(Mage::getStoreConfig('general/locale/timezone'));
                $todayDate = strftime("%Y-%m-%d",Mage::app()->getLocale()->storeTimeStamp(Mage::app()->getStore()->getId()));
                $storeId    = Mage::app()->getStore()->getId();  
                $product    = Mage::getModel('catalog/product');  

                $this->_productCollection = $product->setStoreId($storeId)  
                    ->getCollection()  
                    ->addAttributeToSelect(array('name','status', 'price', 'special_price', 'small_image','required_options','special_from_date', 'special_to_date'), 'inner')
                    ->joinField('stock_status','cataloginventory/stock_status','stock_status',
                        'product_id=entity_id', array(
                          'stock_status' => Mage_CatalogInventory_Model_Stock_Status::STATUS_IN_STOCK,
                          'website_id' => Mage::app()->getWebsite()->getWebsiteId(),
                        ))
                    ->addAttributeToFilter('special_price', array('gt' => 0), 'left')
                    ->addAttributeToFilter('special_from_date', array('date' => true, 'to' => $todayDate))
                    ->addAttributeToFilter('special_to_date', array('or'=> array(
                        0 => array('date' => true, 'from' => $todayDate),
                        1 => array('is' => new Zend_Db_Expr('null')))
                    ), 'left')
                    //->setOrder('created_at', 'desc')
                    ->addAttributeToSort('created_at', 'desc')
                    ->addFinalPrice()
                    ->addStoreFilter()
                    ->setPageSize($this->getProductsLimit())
                    ->setCurPage($page)
                    ->addAttributeToFilter('status', 1)
                    ->addUrlRewrite();

            Mage::getSingleton('catalog/product_status')->addVisibleFilterToCollection($this->_productCollection);  
            //Mage::getSingleton('catalog/product_visibility')->addVisibleInSearchFilterToCollection($this->_productCollection);


                $checkedProducts = new Varien_Data_Collection();
                    foreach ($this->_productCollection as $k => $p) {
                        $p = $p->loadParentProductIds();
                        $parentIds = $p->getData('parent_product_ids');

                        if (is_array($parentIds) && !empty($parentIds)) {
                            if (!$checkedProducts->getItemById($parentIds[0])) {
                                $parentProduct = Mage::getModel('catalog/product')->setStoreId($storeId)->load($parentIds[0]);
                                if ($parentProduct->isVisibleInCatalog()) {
                                    $checkedProducts->addItem($parentProduct);
                                }
                            }
                        } else {
                            if (!$checkedProducts->getItemById($k)) {
                                $checkedProducts->addItem($p);
                            }
                        }
                        if (count($checkedProducts) >= $this->getProductsLimit()) {
                            break;
                        }
                    }
  return $this->_productCollection;  

     }  
} 

结果是一个抓住所有具有特价的产品的页面。然而问题是它引起了某种AJAX冲突，现在分页/过滤器不起作用。

错误是：

GET http://www.yourhealthfoodstore.co.uk/special-offers.html?p=2&isLayerAjax=1 500 Internal Server Error 869ms prototype.js (line 1530)

与prototype.js中的以下函数有关：

  request: function(url) {
    this.url = url;
    this.method = this.options.method;
    var params = Object.isString(this.options.parameters) ?
          this.options.parameters :
          Object.toQueryString(this.options.parameters);

    if (!['get', 'post'].include(this.method)) {
      params += (params ? '&' : '') + "_method=" + this.method;
      this.method = 'post';
    }

    if (params && this.method === 'get') {
      this.url += (this.url.include('?') ? '&' : '?') + params;
    }

    this.parameters = params.toQueryParams();

    try {
      var response = new Ajax.Response(this);
      if (this.options.onCreate) this.options.onCreate(response);
      Ajax.Responders.dispatch('onCreate', this, response);

      this.transport.open(this.method.toUpperCase(), this.url,
        this.options.asynchronous);

      if (this.options.asynchronous) this.respondToReadyState.bind(this).defer(1);

      this.transport.onreadystatechange = this.onStateChange.bind(this);
      this.setRequestHeaders();

      this.body = this.method == 'post' ? (this.options.postBody || params) : null;
      this.transport.send(this.body);

      /* Force Firefox to handle ready state 4 for synchronous requests */
      if (!this.options.asynchronous && this.transport.overrideMimeType)
        this.onStateChange();

    }
    catch (e) {
      this.dispatchException(e);
    }
  },

特别是第1530行：

this.transport.send(this.body);

我对原型/ AJAX没有太多了解，有什么想法可以解决这个问题吗？

由于