Split a WooCommerce order and create a new order if the original order has products in backorder

Question

I have the custom order status and it works.

What I need help with here is looping through the order items and checking if any of them are on backorder and if so, take the backorder items out of the original order and create a new order and give the new order the Backorder status.

The idea is to create the backorder if and only if there are items on backorder in the original order.

add_action( 'woocommerce_checkout_order_processed', 'split_order_if_order_has_backorder_products', 10, 1 );
function split_order_if_order_has_backorder_products( $order_id ) {
    if( ! $order_id ) return;

    // get order object
    $order = new WC_Order( $order_id );

    // get order currency
    $currency = $order->get_currency();

    // get order payment method
    $payment_gateway = $order->get_payment_method();

    // get order items = each product in the order
    $items = $order->get_items();

    foreach ( $items as $item ) {       
        $product = wc_get_product( $item['product_id'] );

        if ( $product->is_on_backorder() ) {

        // THIS IS NOT WORKING FOR SOME REASON?
        $backorder = wc_create_order();         
        $backorder->add_product( $product, $item['quantity'] );
        }
    }

    // THIS IS NOT WORKING EITHER = I NEED TO REMOVE THE BACKORDER ITEMS FROM THE ORIGINAL ORDER, RECALCULATE AND SAVE THE NEW TOTAL
    foreach($items as $backorder_product => $item){
        $order->remove_item($backorder_product);
        $order->calculate_totals();
        $order->save();
    }

    $address = array(
        'first_name' => $order->get_billing_first_name(),
        'last_name'  => $order->get_billing_last_name(),
        'email'      => $order->get_billing_email(),
        'phone'      => $order->get_billing_phone(),
        'address_1'  => $order->get_billing_address_1(),
        'address_2'  => $order->get_billing_address_2(),
        'city'       => $order->get_billing_city(),
        'state'      => $order->get_billing_state(),
        'postcode'   => $order->get_billing_postcode(),
        'country'    => $order->get_billing_country()
    );

    $shipping = array(
        'first_name' => $order->get_shipping_first_name(),
        'last_name'  => $order->get_shipping_last_name(),
        'address_1'  => $order->get_shipping_address_1(),
        'address_2'  => $order->get_shipping_address_2(),
        'city'       => $order->get_shipping_city(),
        'state'      => $order->get_shipping_state(),
        'postcode'   => $order->get_shipping_postcode(),
        'country'    => $order->get_shipping_country()
    );

    // Set addresses
    $backorder->set_address( $address, 'billing' );
    $backorder->set_address( $shipping, 'shipping' );

    // set the correct currency and payment gateway
    $backorder->set_currency($currency);
    $backorder->set_payment_method($payment_gateway);

    // calculate totals
    $backorder->calculate_totals();

    // set order note with original ID
    $backorder->add_order_note('Automated Backorder. Created from the original order ID: '.$order->get_id());

    // give the new backorder the correct status
    $backorder->update_status( 'backorder' );
}

Answer 1

The code below ONLY creates a new order with the products that are in backorder, if the original order contains products with backorder status.

Last update: 02/22 - Tested in WordPress 5.9 & WooCommerce 6.2.0

function action_woocommerce_checkout_order_processed( $order_id, $posted_data, $order ) {
    // Initialize
    $check_for_back_orders = false;

    // Loop through order items
    foreach ( $order->get_items() as $item_key => $item ) {
        // Get product
        $product = $item->get_product();

        // Product is on backorder
        if ( $product->is_on_backorder() ) {
            // Will only be executed once if the order contains back orders
            if ( $check_for_back_orders == false ) {
                $check_for_back_orders = true;

                // Create new order with backorders
                $backorder_order = wc_create_order();
            }

            // Add product to 'backorder' order
            $backorder_order->add_product( $product, $item['quantity'] );

            // Delete item from original order
            $order->remove_item( $item->get_id() );
        }
    }

    // If current order contains backorders, retrieve the necessary data from the existing order and apply it in the new order
    if ( $check_for_back_orders ) {
        // Recalculate and save original order
        $order->calculate_totals();
        $order->save();
        
        // Obtain necessary information
        // Get address
        $address = array(
            'first_name' => $order->get_billing_first_name(),
            'last_name'  => $order->get_billing_last_name(),
            'email'      => $order->get_billing_email(),
            'phone'      => $order->get_billing_phone(),
            'address_1'  => $order->get_billing_address_1(),
            'address_2'  => $order->get_billing_address_2(),
            'city'       => $order->get_billing_city(),
            'state'      => $order->get_billing_state(),
            'postcode'   => $order->get_billing_postcode(),
            'country'    => $order->get_billing_country()
        );

        // Get shipping
        $shipping = array(
            'first_name' => $order->get_shipping_first_name(),
            'last_name'  => $order->get_shipping_last_name(),
            'address_1'  => $order->get_shipping_address_1(),
            'address_2'  => $order->get_shipping_address_2(),
            'city'       => $order->get_shipping_city(),
            'state'      => $order->get_shipping_state(),
            'postcode'   => $order->get_shipping_postcode(),
            'country'    => $order->get_shipping_country()
        );
        
        // Get order currency
        $currency = $order->get_currency();

        // Get order payment method
        $payment_gateway = $order->get_payment_method();
        
        // Required information has been obtained, assign it to the 'backorder' order
        // Set address
        $backorder_order->set_address( $address, 'billing' );
        $backorder_order->set_address( $shipping, 'shipping' );

        // Set the correct currency and payment gateway
        $backorder_order->set_currency( $currency );
        $backorder_order->set_payment_method( $payment_gateway );

        // Calculate totals
        $backorder_order->calculate_totals();

        // Set order note with original ID
        $backorder_order->add_order_note( 'Automated backorder. Created from the original order ID: ' . $order_id );

        // Optional: give the new 'backorder' order the correct status
        //$backorder_order->update_status( 'backorder' );
    }
}
add_action( 'woocommerce_checkout_order_processed', 'action_woocommerce_checkout_order_processed', 10, 3 );

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

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