Magento 2 - product passed to helper parameter is NULL

Question

I created this helper method:

app\code\Company\Base\Helper\Product.php

public function test($product = null)
{
    if (!empty($product)) { exit("TRUE, product is not empty!"); } else { return false; }
}

And injected it into a block, so I can use it there:

THEME\Magento_Catalog\layout\catalog_category_view.xml

<referenceBlock name="category.products.list">
    <arguments>
        <argument name="test" xsi:type="helper" helper="Company\Base\Helper\Product::test" />
    </arguments>
</referenceBlock>

Then I call my helper in THEME\Magento_Catalog\templates\product\list.phtml

<?php /** @var $_product \Magento\Catalog\Model\Product */ ?>
<?php foreach ($_productCollection as $_product) :?>
<?php echo $block->getTest($_product); ?>

This is the template for the category view btw.

But I never get to see "TRUE, product is not empty!".

The same code works great in other locations e.g. on the block product.info.media.image with template Magento_Catalog::product/view/gallery.phtml

Answer 1

You have done wrong. You should use view model https://devdocs.magento.com/guides/v2.3/extension-dev-guide/view-models.html.

I suggest that you have to use view model here instead of helper.

• Create view model class at app/code/Company/Base/ViewModel/Product.php

  and implement test($product = null) method at there.

  like

    <?php

    namespace Company\Base\ViewModel;

    class Product implements \Magento\Framework\View\Element\Block\ArgumentInterface
    {
        public function test($product = null)
        {
            if (!empty($product) || ($product != null)) {
                return true;
            } else {
                return false; 
             }
        }
    }

phtml code look like:

<?php /** @var $_product \Magento\Catalog\Model\Product */ ?>
<?php $viewModel = $block->getViewModel(); ?>
<?php foreach ($_productCollection as $_product) :?>
<?php echo $viewModel->getTest($_product); ?>

Answer 2

The reason why it does not work is because it is not intended to work like this. It is not a helper like in magento 1.

You can use the helper to get data, but you cannot add dynamic parameters into it from the template.

So I had to use xsi:type="object" instead:

<referenceBlock name="category.products.list">         
    <arguments>
        <argument name="company_helper" xsi:type="object">Company\Base\Helper\Product</argument>
    </arguments>
</referenceBlock>

I also had to implement \Magento\Framework\View\Element\Block\ArgumentInterface in my helper class btw.

class Product extends \Magento\Framework\App\Helper\AbstractHelper implements \Magento\Framework\View\Element\Block\ArgumentInterface{
    ...

Then I used it like this:

$_helper = $block->getCompanyHelper();
$isProductNew = $_helper->isProductNew($_product);