If users purchase a product on my site, I give them the option of adding a discounted product to their cart at checkout. However, users are able to remove the original product from cart and the discounted product still remains within the cart.
Is it possible to have it such that if the discounted product is the only one in the cart, then the cart should be empty? I haven't found a way to do this.
What I have tried
Currently, I use the following code from bekarice found on Github:
/**
* Renders a notice and prevents checkout if the cart
* only contains products in a specific category
*/
function sv_wc_prevent_checkout_for_category() {
// set the slug of the category for which we disallow checkout
$category = 'clothing';
// get the product category
$product_cat = get_term_by( 'slug', $category, 'product_cat' );
// sanity check to prevent fatals if the term doesn't exist
if ( is_wp_error( $product_cat ) ) {
return;
}
$category_name = '<a href="' . get_term_link( $category, 'product_cat' ) . '">' . $product_cat->name . '</a>';
// check if this category is the only thing in the cart
if ( sv_wc_is_category_alone_in_cart( $category ) ) {
// render a notice to explain why checkout is blocked
wc_add_notice( sprintf( 'Hi there! Looks like your cart only contains products from the %1$s category – you must purchase a product from another category to check out.', $category_name ), 'error' );
}
}
add_action( 'woocommerce_check_cart_items', 'sv_wc_prevent_checkout_for_category' );
/**
* Checks if a cart contains exclusively products in a given category
*
* @param string $category the slug of the product category
* @return bool - true if the cart only contains the given category
*/
function sv_wc_is_category_alone_in_cart( $category ) {
// check each cart item for our category
foreach ( WC()->cart->get_cart() as $cart_item_key => $cart_item ) {
// if a product is not in our category, bail out since we know the category is not alone
if ( ! has_term( $category, 'product_cat', $cart_item['data']->id ) ) {
return false;
}
}
// if we're here, all items in the cart are in our category
return true;
}
But I don't think it as good a method. Basically, it doesn't allow users to checkout if cart only contains items from a certain category.