How to add entity extension in Shopware 6 App? - shopware

Question

I want to query the categories of the product in the product listing of a Shopware app, so that I can query the customFields of all categories. Is this even possible with an app?
I have already tried via a navigation-page-loaded. And when I override the box-standard.html.twig and access the product, I can't access the categories there.
For each product i want the categories extensions

Answer 1

As the categories association is not loaded for products in the listing you have to fetch the categories using an app script.
As already noted, add the script to the navigation-page-loaded hook, i.e. in Resources/scripts/navigation-page-loaded/category-loader.twig:
{% set products = [] %}
{% if hook.page.cmsPage.type === 'product_list' %}
{% foreach hook.page.cmsPage.sections as section %}
{% foreach section.blocks as sectionBlock %}
{% if sectionBlock.type !== 'product-listing' %}
{% continue %}
{% endif %}
{% foreach sectionBlock.slots as slot %}
{% if slot.type !== 'product-listing' %}
{% continue %}
{% endif %}
{% foreach slot.data.listing.entities as product %}
{% set products = products|merge([product]) %}
{% endforeach %}
{% endforeach %}
{% endforeach %}
{% endforeach %}
{% endif %}
{% set categoryIds = products|reduce((carry, v) => carry|merge(v.categoryIds), []) %}
{% if categoryIds %}
{% set categories = services.repository.search('category', {'ids': categoryIds}) %}
{% foreach products as product %}
{% do product.addArrayExtension('myCategories', {
'categories': categories.entities.getList(product.categoryIds),
}) %}
{% endforeach %}
{% endif %}
Where we first extract all the products, than load the categories of all products at once, and than assign the categories back to the products.
Note that for reading the category entity you need the correct permission, i.e. in the manifest.xml add:
<permissions>
<read>category</read>
<read>category_translation</read>
</permissions>
Now you should be able to access in the box-standard.html.twig template the categories using product.extensions.myCategories.categories.

Answer 2

If I understand your issue correctly, you are trying to access a product's category's custom fields in some piece of storefront logic (like a Twig template).
The way I see it, you would have to add a script that would enable you to query the repository for the categories and their custom fields. The issue is, a SalesChannelProductEntity will not contain the information about all its categories (only the SeoCategory), so you might need to first query the product_category repository.
Generally, it is going to be complicated but it should be doable.