Use CMS blocks inside product attributes

Question

I want to use CMS blocks inside product attributes, eg in description and short description.

• inside product description I've added {{block id="test1"}}.
• i have two observer
  • catalog_product_collection_load_after for collections
  • catalog_controller_product_view for products

Observer:

public function execute(Observer $observer): void
{
    $product = $observer->getProduct();
    $this->helper->parse($product);
}

Helper:

use Magento\Cms\Model\Template\FilterProvider
...
public function __construct(Context $context, FilterProvider $filterProvider)
{
    $this->filterProvider = $filterProvider;
    parent::__construct($context);
}

public function parse(Product $product): void
{
    # some code to get attribute code and value
    ...
    $attributeValue = $this->insertCmsBlocks($product, $attributeCode, $attributeValue);
    $product->setData($attributeCode, $attributeValue);
}

public function insertCmsBlocks(Product $product, string $attributeCode, string $attributeValue): string
{
    ...
    $attributeValue = $this->filterProvider->getBlockFilter()->filter($attributeValue);
    ...

    return $attributeValue;
}

---

Category page

This works w/o any problems ...

---

Product page

Instead of default LUMA theme product page "compare" and "wishlist" block is loaded ...

---

• block_html and full_page is disabled ...
• $this->filterProvider->getBlockFilter()->filter($attributeValue) looks ok when debugging

If I comment $this->filterProvider->getBlockFilter()->filter($attributeValue) everthing works ... so, there is no problem with the event, cache or $product->setData() ...

Any ideas whats wrong with this code?

Answer 1

Let me suggest a slightly different way of processing the attributes on the product pages that I think might be better. The core uses the \Magento\Catalog\Helper\Output class to process them and it has an addHandler() method. It takes a class as a callback and executes a method on it, allowing your code to be very clean. So instead of using an event, add a plugin:

<type name="Magento\Catalog\Helper\Output"> 
    <plugin name="Example::attribute_handler" type="Example\Module\Plugin\Product\AttributeHandler"/>
</type>

Add the product attribute handler (this can be used for category attributes too) and inject your helper into the constructor. The product attribute handlers need an arbitrary name, as you can see in the method definition.

namespace Example\Module\Plugin\Product;

class AttributeHandler
{
    private $attributeHandler;

    public function __construct(\Example\Module\Model\Processor\Attribute\Handler $attributeHandler)
    {
        $this->attributeHandler = $attributeHandler;
    }

    public function beforeProductAttribute(\Magento\Catalog\Helper\Output $context, $subject)
    {
        if (count($context->getHandlers('productattribute')) < 1) {
            $context->addHandler('productAttribute', $this->attributeHandler);
        }
    }
}

Last, update your helper to include a productAttribute() method. I like to check for the existence of a substring {{ before running the processor to make it more efficient if there is not blocks / widgets.

The productAttribute() method would look like this in your case (I would abstract insertCmsBlocks() further to include a method that does not require Product):

public function productAttribute(\Magento\Catalog\Helper\Output $context, $value, $params)
{
    if ($value && strpos((string) $value, '{{') !== false) {
        $value = $this->filter($value);
    }

    return $value;
}

One benefit of this approach is that it works anywhere the Magento_Catalog product attribute handler is used.

Answer 2

Are you using FPC?
The catalog_controller_product_view event cannot be used in conjunction with FPC cache since Magento will not raise it after the first visit.

See here for a possible solution