Check if WooCommerce Coupon already exists

Question

I'm editing a packing slip, which is generated when the order is paid and being packed. The packing slip automatically adds a coupon which will be printed on it as well, if a product of a certain category is included.

My problem is, that every time I refresh or reopen the packing slip, a new coupon is being generated with the same coupon code. So I would like to implement a rule, that checks if the coupon_code already exists.

add_action( 'wpo_wcpdf_after_order_details', 'wpo_wcpdf_custom_text_categories', 10, 2 );
function wpo_wcpdf_custom_text_categories ($template_type, $order) {
    // collect categories from order items
    $order_cats = array();
    $items = $order->get_items();
    foreach ($items as $item_id => $item) {
        $product = $order->get_product_from_item($item);
        if ($product) {
            $terms = get_the_terms( $product->id , 'product_cat' );
            foreach ($terms as $term) {
                $order_cats[$term->term_id] = $term->name;
            }
        }
    }
    $target = array('Testtragen', 'Testtragetuch');
    // 
    // check for your category requirement
    if(count(array_intersect($order_cats, $target)) > 0 && $template_type == 'packing-slip'){
        $coupon_code = $order->get_order_number();
        $discount_type = 'fixed_product'; // Type: fixed_cart, percent, fixed_product, percent_product       
        $order_date = get_post_meta( $order->id, '_wcpdf_order_date', true );
        $due_date = date_i18n( get_option( 'date_format' ), strtotime( $invoice_date . ' + 60 days') );
        $email = $order->billing_email;   



        $amount = '10'; // Amount
        $discount_type = 'fixed_cart'; // Type: fixed_cart, percent, fixed_product, percent_product

        $coupon = array(
            'post_title'   => $coupon_code,
            'post_content' => '',
            'post_status'  => 'publish',
            'post_author'  => 1,
            'post_type'    => 'shop_coupon'
        );
        /*          
        $new_coupon_id = wp_insert_post( $coupon );

        // Add meta
        update_post_meta( $new_coupon_id, 'discount_type', $discount_type );
        update_post_meta( $new_coupon_id, 'coupon_amount', $amount );
        update_post_meta( $new_coupon_id, 'individual_use', 'no' );
        update_post_meta( $new_coupon_id, 'product_ids', '' );
        update_post_meta( $new_coupon_id, 'exclude_product_ids', '' );
        update_post_meta( $new_coupon_id, 'usage_limit', '' );
        update_post_meta( $new_coupon_id, 'expiry_date', '' );
        update_post_meta( $new_coupon_id, 'apply_before_tax', 'yes' );
        update_post_meta( $new_coupon_id, 'free_shipping', 'no' );   
        */
    }
}

So I would like to add an if statement before the wp_insert_post($coupon), that all this code only gets executed if the coupon with the coupon_code doesn't already exist.

I tried : term_exists( $coupon_code, ‘coupons’)but this didn't work.

Thanks for your help!

Answer 1

Update (added WooCommerce 3 compatibility)

Here it is a solution creating a special meta_key for the $order->id to avoid new coupon generation with the same coupon code, when refreshing or reopening the packing slip.

Here is your changed code (with comment explanations):

add_action( 'wpo_wcpdf_after_order_details', 'wpo_wcpdf_custom_text_categories', 10, 2 );
function wpo_wcpdf_custom_text_categories ($template_type, $order) {
    // collect categories from order items
    $order_cats = array();

    $order_id = method_exists( $order, 'get_id' ) ? $order->get_id() : $order->id;

    // Loop through order items
    foreach ($order->get_items() as $item_id => $item) {
        $product = version_compare( WC_VERSION, '3.0', '<' ) ? $product_id = version_compare( WC_VERSION, '3.0', '<' ) ? $cart_item['data']->id : $cart_item['data']->get_id() : $item->get_product();
        $product_id = method_exists( $product, 'get_id' ) ? $item->get_product_id() : $item['product_id'];
        if ($product) {
            $terms = get_the_terms( $product_id , 'product_cat' );
            foreach ($terms as $term) {
                $order_cats[$term->term_id] = $term->name;
            }
        }
    }
    $target = array('Testtragen', 'Testtragetuch');
    // 
    // check for your category requirement
    if(count(array_intersect($order_cats, $target)) > 0 && $template_type == 'packing-slip'){
        $coupon_code = $order->get_order_number();
        $discount_type = 'fixed_product'; // Type: fixed_cart, percent, fixed_product, percent_product       
        $order_date = get_post_meta( $order_id, '_wcpdf_order_date', true );
        $due_date = date_i18n( get_option( 'date_format' ), strtotime( $invoice_date . ' + 60 days') );
        $email = method_exists( $order, 'get_billing_email' ) ? $order->get_billing_email() : $order->billing_email;

        $amount = '10'; // Amount
        $discount_type = 'fixed_cart'; // Type: fixed_cart, percent, fixed_product, percent_product

        $coupon = array(
            'post_title'   => $coupon_code,
            'post_content' => '',
            'post_status'  => 'publish',
            'post_author'  => 1,
            'post_type'    => 'shop_coupon'
        );


        // @@@ We create a meta_key '_wcpdf_coupon' for this order with value 'no'
        if( empty( get_post_meta( $order_id, '_wcpdf_coupon', true) ) ) {
            add_post_meta( $order_id, '_wcpdf_coupon', 'no', true );
        }

        // @@@ if this meta_key for this order has a value = 'no' was update it to 'yes'
        if( get_post_meta( $order_id, '_wcpdf_coupon', true) == 'no' ) {

            // Now we update it to 'yes'. This avoid the coupon be reused for this order.
            update_post_meta( $order_id, '_wcpdf_coupon', 'yes');

            $new_coupon_id = wp_insert_post( $coupon );

            // Add meta
            update_post_meta( $new_coupon_id, 'discount_type', $discount_type );
            update_post_meta( $new_coupon_id, 'coupon_amount', $amount );
            update_post_meta( $new_coupon_id, 'individual_use', 'no' );
            update_post_meta( $new_coupon_id, 'product_ids', '' );
            update_post_meta( $new_coupon_id, 'exclude_product_ids', '' );
            update_post_meta( $new_coupon_id, 'usage_limit', '' );
            update_post_meta( $new_coupon_id, 'expiry_date', '' );
            update_post_meta( $new_coupon_id, 'apply_before_tax', 'yes' );
            update_post_meta( $new_coupon_id, 'free_shipping', 'no' );
        }
    }
}

This should solve this issue…