Magento 2: How to create custom layout instructions to match a custom product page layout?

Question

I am trying to work on a product subscriptions page which is very different in function from a standard product page. I have created my new Magento_Theme/page_layout/subscription.xml I set Magento 2 to use my custom layout for the product I want.

My question is, how do I create a custom set of layout instructions Magento_Catalog/layout/catalog_product_view.xmlto be used only with Magento_Theme/page_layout/subscription.xml ?

I still need most catalog_product_view pages to use the standard layout instructions. The main reason for this, is that subscription pages are going to be so different I need entirely different XML for the page layout.

Essentially, I would like to have a specific paired page_layout and layout for the subscription products.

Thanks!

Answer 1

There's a method called addPageLayoutHandles in Magento\Framework\View\Result\Page that you can make a plugin for, such as:

<?php

namespace Some\Module\Plugin;


use Magento\Catalog\Api\ProductRepositoryInterface;
use Magento\Framework\View\Result\Page;

class ProductLayout
{
    protected $productRepository;

    public function __construct(ProductRepositoryInterface $productRepository)
    {
        $this->productRepository = $productRepository;
    }

    public function beforeAddPageLayoutHandles(Page $subject, ...$args)
    {
        if (is_array($args) && count($args) == 1) {
            $params = $args[0];
            if (isset($params['sku'])) {

                $product = $this->productRepository->getById($params['id']);

                if ($product->getPageLayout() === 'subscription') {
                    $subject->getLayout()->getUpdate()->removeHandle($subject->getDefaultLayoutHandle());
                    return [$params, 'catalog_product_subscription'];
                }
            }
        }

        return $args;
    }
}

Basically this checks that the name of the page layout for the requested product is subscription and if so it removes the default layout handle (catalog_product_view) and adds the layout handle catalog_product_subscription.

Then you need a frontend layout file called catalog_product_subscription.xml containing your alternate layout code.