If your store uses a customized logic for handling product's categories you might need to amend categories in Nosto module as well . Start by reading and .
If overriding the product data directly does not seem the best option for you, you can create a service class and make use of Dependency Injection pattern.
Create a new class which will implement CategoryServiceInterface. Override the required functions and afterwards replace CategoryServiceInterface with MyCategoryServive in the DI etc/di.xml
<?php
namespace My\Nosto\Model\Service;
use Nosto\Tagging\Model\Service\Product\Category\CategoryServiceInterface;
use Magento\Catalog\Model\Category;
use Magento\Catalog\Model\Product;
use Magento\Store\Api\Data\StoreInterface;
class MyCategoryServive implements CategoryServiceInterface
{
/**
* Method used to return a single category string for given category object
* @param Category $category
* @param StoreInterface $store
* @return null|string
*/
public function getCategory(Category $category, StoreInterface $store) {
//ToDo Implement logic
}
/**
* Method used to return list of strings representing categories for a given product
* @param Product $product
* @param StoreInterface $store
* @return array
*/
public function getCategories(Product $product, StoreInterface $store) {
}
}
