getCustomAttribute() not working on collection items

Question

If I pull a list of products with the repository I am unable to get any custom attributes.

    $searchCriteria = $this->searchCriteriaBuilder->addFilter('type_id', 'simple', 'eq')->create();
    $simpleProdSearch = $this->productRepository->getList($searchCriteria);
    $simpleProds = $simpleProdSearch->getItems();

    foreach($simpleProds as $product)
    {
        $cats = $product->getCustomAttribute('category_ids'); // null
    }

If I load the product by ID then it works:

    foreach($simpleProds as $product)
    {
        $fullProduct = $this->productRepository->getById( $product->getId() );
        $cats = $fullProduct->getCustomAttribute('category_ids');
    }

But this loads the product twice. I am performing action on all products so I want this to be performant as possible. Can I add the category IDs to the full collection of products?

Answer 1

try below code

$cats= $product->getResource()->getAttribute('category_ids')->getFrontend()->getValue($product);