Update prices catalog_product_attribute_update_before instead of catalog_product_save_before

Question

I wrote module that is updating prices when I click save product. It's using catalog_product_save_before and its loading extra attributes like:

    $price1 = $product->getprice_extra1();
    $price2 = $product->getprice_extra2();
    $price3 = $product->getprice_extra3();

and its work perfectly, however to calculate all prices I need to manually open product and save.

I was trying to use prices catalog_product_attribute_update_before event and save using selection of products and change attributes in product list but its throwing php error:

PHP Fatal error: Uncaught Error: Call to a member function getprice_extra1() on null in ...

Same error when I try to use events: update after import and cron.

I think when I'm using this different events I need to load something else.

Or maybe some of attributes are without value and this is causing error.

UPDATE:

It looks like on update attributes all products data is not loaded I need add something with @var \Magento\Framework\Registry

Answer 1

That means your $product object is null.

Your event catalog_product_attribute_update_before is written as this:

public function updateAttributes($productIds, $attrData, $storeId)
{
    $this->_eventManager->dispatch(
        'catalog_product_attribute_update_before',
        ['attributes_data' => &$attrData, 'product_ids' => &$productIds, 'store_id' => &$storeId]
    );

You may have noticed, there is product_ids are passed but not product object.

So, you will need to loop to all the ids and then load the product object, then do your logic.

Try this:

protected $_product;

//in construction
// \Magento\Catalog\Model\ProductFactory $product

$this->_product = $product;

//now load it in your function

$productIds = $observer->getProductIds();
foreach($productIds as $id){
    $product = $this->_product->create()->load($id);
    if($product->getId()){
       //do your stuff here
    }
}

Hope, this helps.