Call to a member function getId() on null - module-catalog/Helper/Product.php

Question

I added sample data to my magento2 website, but when I want to access to a product I always get this error :

Fatal error: Uncaught Error: Call to a member function getId() on null in /var/www/html/test/vendor/magento/module-catalog/Helper/Product.php:313 Stack trace: #0 /var/www/html/test/vendor/magento/module-catalog/Helper/Product.php(430): Magento\Catalog\Helper\Product->canShow(NULL) #1 /var/www/html/test/vendor/magento/module-catalog/Helper/Product/View.php(263): Magento\Catalog\Helper\Product->initProduct(1562, Object(Magento\Catalog\Controller\Product\View\Interceptor), Object(Magento\Framework\DataObject)) #2 /var/www/html/test/vendor/magento/module-catalog/Controller/Product/View.php(118): Magento\Catalog\Helper\Product\View->prepareAndRender(Object(Magento\Framework\View\Result\Page\Interceptor), 1562, Object(Magento\Catalog\Controller\Product\View\Interceptor), Object(Magento\Framework\DataObject)) #3 /var/www/html/test/vendor/magento/framework/App/Action/Action.php(108): Magento\Catalog\Controller\Product\View->execute() #4 /var/www/html/test/vendor/magento/framework/Interception/Interceptor.php(58): Magento\Framewor in /var/www/html/test/vendor/magento/module-catalog/Helper/Product.php on line 313

The Product.php code :

public function canShow($product, $where = 'catalog')
    {
        if (is_int($product)) {
            try {
                $product = $this->productRepository->getById($product);
            } catch (NoSuchEntityException $e) {
                return false;
            }
        } else {
       /*313*/     if (!$product->getId()) {
                return false;
            }
        }
        return $product->isVisibleInCatalog() && $product->isVisibleInSiteVisibility();
    }

when I var_dump($product) it's return NULL

Product.php class code : https://snipsave.com/saadsaad/#/snippet/iDIEafixLtWgzWO9sK

is there any solution?

Answer 1

After a lot of search, I found that the problem was on di.xml

because I added this:

<preference for="Magento\Catalog\Api\ProductRepositoryInterface" 
        type="Testing\HelloWorld\Model\CustomImplementation" />

so I remove it and it's work

Answer 2

Change your code from if (!$product->getId()) to if (!$product) it should work

complete code would be:

public function canShow($product, $where = 'catalog')
{
    if (is_int($product)) {
        try {
            $product = $this->productRepository->getById($product);
        } catch (NoSuchEntityException $e) {
            return false;
        }
    } else {
   /*313*/     
        if (!$product) {
            return false;
        }
    }
    return $product->isVisibleInCatalog() && $product->isVisibleInSiteVisibility();
}

Answer 3

Try this one:
null will be returned if the object is null.

public function canShow($product, $where = 'catalog')
    {
        if (is_int($product)) {
            try {
                $product = $this->productRepository->getById($product);
            } catch (NoSuchEntityException $e) {
                return false;
            }
        } else {
                return $product ? $product->getId() : null;
        }
        return $product->isVisibleInCatalog() && $product->isVisibleInSiteVisibility();
    }