magento 产品列表排序、分页功能

我们以 catalog_category_layered 控制器为例说明

在catalog.xml 找到catalog_category_layered配置段

    <catalog_category_layered translate="label">
            <label>Catalog Category (Anchor)</label>
            <reference name="left">
                <block type="catalog/layer_view" name="catalog.leftnav" after="currency" template="catalog/layer/view.phtml"/>
            </reference>
            <reference name="content">
                <block type="catalog/category_view" name="category.products" template="catalog/category/view.phtml">
                    <span style="color:#cc0000;"><block type="catalog/product_list" name="product_list" 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></span>
                        <action method="addColumnCountLayoutDepend"><layout>empty</layout><count>6</count></action>
                        <action method="addColumnCountLayoutDepend"><layout>one_column</layout><count>5</count></action>
                        <action method="addColumnCountLayoutDepend"><layout>two_columns_left</layout><count>4</count></action>
                        <action method="addColumnCountLayoutDepend"><layout>two_columns_right</layout><count>4</count></action>
                        <action method="addColumnCountLayoutDepend"><layout>three_columns</layout><count>3</count></action>
                       <span style="color:#cc0000;"> <action method="setToolbarBlockName"><name>product_list_toolbar</name></action></span>
                    <span style="color:#cc0000;"></block></span>
                </block>
            </reference>
        </catalog_category_layered>  

其中catalog/product_list是产品显示的block，而catalog/product_list_toolbar是控制产品排序和分页功能的Block,而把这两个block联系起来的关键就是

    <span style="color: rgb(204, 0, 0); "> <action method="setToolbarBlockName"><name>product_list_toolbar</name></action></span>  

下面来看下实现排序、分页功能的步骤

1、根据配置文件实例化catalog/product_list Block并调用setToolbarBlockName方法设置ToolbarBlock的名字

2、在catalog/product_list block类（Mage_Catalog_Block_Product_List）的_beforeToHtml()方法中实例化ToolbarBlock，并对产品做排序和分页

    protected function _beforeToHtml()
        {
           <span style="color:#000099;"> $toolbar = $this->getToolbarBlock();//实例化ToolbarBlock</span>  

            // called prepare sortable parameters
           <span style="color:#000099;"> $collection = $this->_getProductCollection();//获取产品集合
    </span>        // use sortable parameters
            if ($orders = $this->getAvailableOrders()) {
                $toolbar->setAvailableOrders($orders);
            }
            if ($sort = $this->getSortBy()) {
                $toolbar->setDefaultOrder($sort);
            }
            if ($dir = $this->getDefaultDirection()) {
                $toolbar->setDefaultDirection($dir);
            }
            if ($modes = $this->getModes()) {
                $toolbar->setModes($modes);
            }  

            <span style="color:#000099;">// set collection to toolbar and apply sort
            $toolbar->setCollection($collection);//用ToolbarBlock实例对产品集合排序和分页</span>  

          <span style="color:#3333ff;">  $this->setChild('toolbar', $toolbar);//设置ToolbarBlock实例为当前Block的Child，在显示的时候会有用</span>  

            Mage::dispatchEvent('catalog_block_product_list_collection', array(
                'collection' => $this->_getProductCollection()
            ));  

            $this->_getProductCollection()->load();  

            return parent::_beforeToHtml();
        }  

    <span style="color:#000099;">$toolbar->setCollection($collection);</span>  

是如何实现排序和分页功能呢，来看这个方法就知道了，打开Mage_Catalog_Block_Product_List_Toolbar类

    public function setCollection($collection)
        {
            $this->_collection = $collection;//对象引用  

           <span style="color:#009900;"> $this->_collection->setCurPage($this->getCurrentPage());  

            // we need to set pagination only if passed value integer and more that 0
            $limit = (int)$this->getLimit();
            if ($limit) {
                $this->_collection->setPageSize($limit);
            }//分页功能</span>
            <span style="color:#3333ff;">if ($this->getCurrentOrder()) {
                $this->_collection->setOrder($this->getCurrentOrder(), $this->getCurrentDirection());
            }//排序功能</span>
            return $this;
        }  

3、显示

在product list 的phtml文件中调用Mage_Catalog_Block_Product_List类的getToolbarHtml()方法

    <?php echo $this->getToolbarHtml() ?>  

    public function getToolbarHtml()
        {
            return $this->getChildHtml('toolbar');//显示它的Child Block 与_beforeToHtml()中的$this->setChild('toolbar', $toolbar);相对应
        }