Call to a member function getAttributes() on null

Question

I have a php code for creating a product feed XML, including all the additional attributes of the products. It worked fine until I upgraded from 1.9.3.1 to 1.9.3.4.

After the upgrade my script gives this error:

PHP Fatal error:  Call to a member function getAttributes() on null in /www/new/app/code/core/Mage/Catalog/Block/Product/View/Attributes.php on line 58. 

My codepart which takes care of extracting the additional attributes:

        $_helper = Mage::helper('catalog/output');
        $add = new Mage_Catalog_Block_Product_View_Attributes();
        $add->setProduct($productId);
        $_additional = $add->getAdditionalData(); 

        $_product = Mage::getModel('catalog/product');
        $_product->setStoreId($storeId);
        $_product->load($productId); 


        foreach ($_additional as $_data): 

        $_attribute = $_product->getResource()->getAttribute($_data['code']);
            if (!is_null($_product->getData($_attribute->getAttributeCode())) && ((string)$_attribute->getFrontend()->getValue($_product) !='') && (!is_null($_data['label'])) && (!is_null($_data['value'])))
        {
        $produs->appendChild($xml->createElement(str_replace(" ","_", preg_replace("/[^A-Za-z0-9_ ]/", "",$_data['label'])), str_replace($replace_from, $replace_to, strip_tags($_helper->productAttribute($_product, $_data['value'], $_data['code'])))));
        } 
        endforeach; 

What has changed between the two versions and what should I modify in my code to make it work again?

Answer 1

Looking into the source of app/code/core/Mage/Catalog/Block/Product/View/Attributes.php it appears that $product = $this->getProduct(); (from line 57) is not returning the product, backtracking to the getProduct() method, tells me that the product has not been set in the registry ie: Mage::registry('product'); returns NULL. You could try the following code to see if it fixes the issue.

$_helper = Mage::helper('catalog/output');
    $add = new Mage_Catalog_Block_Product_View_Attributes();
    $add->setProduct($productId);


    $_product = Mage::getModel('catalog/product');
    $_product->setStoreId($storeId);
    $_product->load($productId); 


    Mage::register('product', $_product);
    $_additional = $add->getAdditionalData();

    foreach ($_additional as $_data): 

    $_attribute = $_product->getResource()->getAttribute($_data['code']);
        if (!is_null($_product->getData($_attribute->getAttributeCode())) && ((string)$_attribute->getFrontend()->getValue($_product) !='') && (!is_null($_data['label'])) && (!is_null($_data['value'])))
    {
    $produs->appendChild($xml->createElement(str_replace(" ","_", preg_replace("/[^A-Za-z0-9_ ]/", "",$_data['label'])), str_replace($replace_from, $replace_to, strip_tags($_helper->productAttribute($_product, $_data['value'], $_data['code'])))));
    } 
    endforeach; 

    Mage::unregister('product');