WooCommerce custom code deleting item as soon as it's added to cart

Question

I am trying to set up a custom coupon code so that customers can add an add-on product to their cart, only if their cart total is $50 or more.

I am using Allow add to cart for specific products based on cart total in WooCommerce answer code that allows or denies adding the product depending on their cart total and this is working great.

My issue is that I have another bit of code that is supposed to delete the addon item if it's in the cart and the cart total is no longer within the threshold.

In my case I have the threshold set to $50, and the addon product costs $10.

In testing I've found that when the cart total is $60 or more, everything works fine. I can even remove a couple of items from the cart and the addon item will stay until the total is under the threshold, then it gets removed as well.

However if the cart total is anywhere between $50 and $60 when I go to add the addon item, the addon item is immediately deleted as soon as it's added.

I would expect the order of operations to go

Checks the cart total, finds that it is above $50
Allows me to add the addon item
Checks the cart total with the addon item included, finds that it is now above $60
Allows the addon to stay

Based on Add or remove specific cart Item based on WooCommerce cart total answer code, here is the code I'm using:

add_action( 'woocommerce_before_calculate_totals', 'add_or_remove_cart_items', 10, 1 );
function add_or_remove_cart_items( $cart ) {
    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;

    // ONLY for logged users (and avoiding the hook repetition) 
    if ( ! is_user_logged_in() && did_action( 'woocommerce_before_calculate_totals' ) >= 2 )
        return;

    $threshold_amount = 50; // The threshold amount for cart total
    $addon_product_id  = 7039; // ID of the addon item
    $addon_product_cost = 10; // Cost of addon item
    $cart_items_total = 0; // Initializing
    $threshold_amount_with_addon = $threshold_amount + $addon_product_cost;

    // Loop through cart items
    foreach ( $cart->get_cart() as $cart_item_key => $cart_item ){
        // Check if the free product is in cart
        if ( $cart_item['data']->get_id() == $addon_product_id ) {
            $addon_item_key = $cart_item_key;
        }
        // Get cart subtotal incl. tax from items (with discounts if any)
        $cart_items_total += $cart_item['line_total'] + $cart_item['line_tax'];
    }

    // If cart total is below the defined amount and addon product is in cart, we remove it.
    if ( $cart_items_total < $threshold_amount_with_addon && isset($addon_item_key) ) {
        $cart->remove_cart_item( $addon_item_key );
        return;
    }
}

I can't for the life of me figure out what is going wrong. Any help would be much appreciated.

LoicTheAztec LoicTheAztec · Accepted Answer · 2021-03-02T00:52:11

Below, we exclude the Add-On item from subtotal calculation so we don't need to add the Add-On price to threshold amount (so we keep your steps 1, 2 and 4).

The revisited code:

add_action( 'woocommerce_before_calculate_totals', 'add_or_remove_cart_items', 10, 1 );
function add_or_remove_cart_items( $cart ) {
    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;

    // ONLY for logged users, avoiding the hook repetition
    if ( ! is_user_logged_in() || did_action( 'woocommerce_before_calculate_totals' ) >= 2 )
        return;

    $addon_product_id = 7039; // ID of the addon item
    $threshold_amount = 50; // The threshold amount
    $cart_items_total = 0; // Initializing

    // Loop through cart items
    foreach ( $cart->get_cart() as $cart_item_key => $cart_item ){
        // For Add-On product: Check if it is in cart
        if ( in_array( $addon_product_id, [$cart_item['product_id'], $cart_item['variation_id']] ) ) {
            $addon_item_key = $cart_item_key;
        }
        // For other items: add their line total including taxes to items subtotal
        else {
            // Sum dicounted line total incl. taxes to get other items subtotal
            $cart_items_total += $cart_item['line_total'] + $cart_item['line_tax'];
        }
    }

    // If cart total is below the defined amount and addon product is in cart, we remove it.
    if ( $cart_items_total < $threshold_amount && isset($addon_item_key) ) {
        $cart->remove_cart_item( $addon_item_key );
    }
}

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

WooCommerce custom code deleting item as soon as it's added to cart

1 Answers