What is the equivalent of the config node category/collection/attributes in Magento 2 to add an attribute to the category collection

Question

I am porting a Magento 1 module, which adds a custom category attribute, to Magento 2.

The product is already created in Magento 2 - but now it does not appear in the inside \Magento\Catalog\Helper\Category::getCategoryUrl.

In the Magento 1 version config.xml I had:

<config>          
        <frontend>
          <category>
              <collection>
                  <attributes>
                      <redirect_url />
                  </attributes>
              </collection>
          </category>
      </frontend>
</config>

This solved the problem.

What is the equivalent of this in Magento 2 ?

Sure, I could load the full category item again in the above method, but this would slow down the site.

Answer 1

Create etc/catalog_attributes.xml in your extension with the following content:

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Catalog:etc/catalog_attributes.xsd">
    <group name="catalog_category">
        <attribute name="redirect_url"/>
    </group>
</config>