Magento block rewrite not working properly - magento

Question

I am trying to rewrite product_new block. Purpose is that i want to add category_id field and fetch new products of one category only. Here is the code
app\code\local\Foo\Bar\Block\Product\New.php
class Foo_Bar_Block_Product_New extends Mage_Catalog_Block_Product_New
{
protected function _beforeToHtml()
{
// echo "aaaaaaasdfa";
$todayDate = Mage::app()->getLocale()->date()->toString(Varien_Date::DATETIME_INTERNAL_FORMAT);
$collection = Mage::getResourceModel('catalog/product_collection');
$collection->setVisibility(Mage::getSingleton('catalog/product_visibility')->getVisibleInCatalogIds());
$collection = $this->_addProductAttributesAndPrices($collection)
->addStoreFilter()
->addAttributeToFilter('news_from_date', array('date' => true, 'to' => $todayDate))
->addAttributeToFilter('news_to_date', array('or'=> array(
0 => array('date' => true, 'from' => $todayDate),
1 => array('is' => new Zend_Db_Expr('null')))
), 'left')
->addAttributeToSort('news_from_date', 'desc')
->setPageSize($this->getProductsCount())
->setCurPage(1)
;
if($categoryId=$this->getData('category_id')){
$category = Mage::getModel('catalog/category')->load($categoryId);
$collection->addCategoryFilter($category);
}
$this->setProductCollection($collection);
return parent::_beforeToHtml();
}
}
Added block in local.xml using below code
<block type="foo_bar/product_new" name="new_products_list" template="catalog/product/new.phtml">
<action method="setCategoryId"><category_id>4</category_id></action>
<action method="setColumnCount"><columns>4</columns></action>
</block>
module's config.xml is
<global>
<blocks>
<catalog>
<rewrite>
<product_new>Foo_Bar_Block_Product_New</product_new>
</rewrite>
</catalog>
</blocks>
</global>
Please guide me where I am making mistake
Thanks

Answer 1

Issue is on parent::_beforeToHtml(); statement it will call _beforeToHtml method of parent class which is Mage_Catalog_Block_Product_New. So parent function will override collection which you have set.
Solution:
Replace :
parent::_beforeToHtml();
to :
Mage_Catalog_Block_Product_Abstract::_beforeToHtml();