Exclude variations with 2 specific attribute terms from coupon usage in Woocommerce

Question

I need to prevent coupons being used if customer have any specific product variations in their cart with following attribute terms:

• attribute_pa_style => swirly
• attribute_pa_style => circle

I've looked through the Woocommerce scripts that apply to restricting specific products and specific categories, but can't figure it out with regard to attributes and all coupons.

Any help is appreciated.

Answer 1

This can be done using woocommerce_coupon_is_valid filter hook this way:

add_filter( 'woocommerce_coupon_is_valid', 'check_if_coupons_are_valid', 10, 3 );
function check_if_coupons_are_valid( $is_valid, $coupon, $discount ){
    // YOUR ATTRIBUTE SETTINGS BELOW:
    $taxonomy   = 'pa_style';
    $term_slugs = array('swirly', 'circle');

    // Loop through cart items and check for backordered items
    foreach ( WC()->cart->get_cart() as $cart_item ) {
        foreach( $cart_item['variation'] as $attribute => $term_slug ) {
            if( $attribute === 'attribute_'.$taxonomy && in_array( $term_slug, $term_slugs ) ) {
                $is_valid = false; // attribute found, coupons are not valid
                break; // Stop and exit from the loop
            }
        }
    }
    return $is_valid;
}

Code goes in function.php file of your active child theme (or active theme). Tested and works.

Answer 2

You could also check each product in the cart and restrict it from the coupon with woocommerce_coupon_is_valid_for_product

/**
 * exclude a product from an coupon by attribute value
 */
add_filter('woocommerce_coupon_is_valid_for_product', 'exclude_product_from_coupon_by_attribute', 12, 4);
function exclude_product_from_coupon_by_attribute($valid, $product, $coupon, $values ){
    /**
     * attribute Settings
     */
    $taxonomy = 'pa_saison';
    $term_slugs = array('SS22');

    /**
     * check if the product has the attribute and value 
     * and if yes restrict this product from the coupon
     */
    if(in_array($product->get_attribute($taxonomy), $term_slugs)) {
        $valid = false;

    /**
     * otherwise check if its a variation product
     */
    } elseif($product->parent_id) {
        /**
         * set the parent product
         */
        $parent = wc_get_product($product->parent_id);
        
        /**
         * check if parent has an attribute with this value
         */
        if(in_array($parent->get_attribute($taxonomy), $term_slugs)) {
            $valid = false;
        }

    /**
     * for all other products which does not have the attribute with the value
     * set the coupon to valid
     */
    } else {
        $valid = true;
    }

    return $valid;
}

I have tested it on my site and it works as expected.