Remove Specific Categories From Related Products In Woocommerce

woocommerce-remove-specific-categories-from-related-products.php

/**
 * @snippet       Exclude Specific Category From Related Products
 * @author        Rasool Vahdati
 * @compatible    WooCommerce 6
 */

/**
 * Filters the related products to exclude specific categories.
 *
 * @param array $related_posts An array of related product IDs.
 * @param int   $product_id     The ID of the current product.
 * @param array $args           Arguments passed to the related products query.
 * @return array                An array of filtered related product IDs.
 */
function exclude_category_related_products( $related_posts, $product_id, $args )
{
    // Rewrite related posts
    $new_related_posts = [];

    // Exclude all products from specific categories
    $exclude_category_ids = array( 101, 150 );

    // Get all product IDs in categories with specified term IDs
    $category_ids = get_posts( array(
        'post_type'        => 'product',
        'posts_per_page'   => -1,
        'tax_query'        => array(
            array(
                'taxonomy' => 'product_cat',
                'field'    => 'term_id',
                'terms'    => $exclude_category_ids,
                'operator' => 'NOT IN',
            ),
        ),
        'fields'    => 'ids', // only get post ids
    ) );

    foreach($related_posts as $related_id)
    {
        if( ! in_array( $related_id, $category_ids ) )
            $new_related_posts[] = $related_id;
    }

    return $new_related_posts;
}

add_filter( 'woocommerce_related_products', 'exclude_category_related_products', 100, 3 );