One-Page Checkout [Support Thread]

[lat9]

v2.6.1 of One-Page Checkout is now available for download: https://www.zen-cart.com/downloads.php?do=file&id=2095

This release contains changes for these GitHub issues:

#462: Ensure $_POST['order_id'] is an int.
#461: Fix event-handler duplication on checkout_one page

[njcyx]

opc v2.6.1, zc2.1.0, paypalwpp, php 8.1

I received the following intermittent warning.

[11-May-2026 15:08:12 America/New_York] PHP Fatal error: Uncaught Error: Typed property OnePageCheckout::$isVirtualOrder must not be accessed before initialization in /includes/classes/OnePageCheckout.php:2568
Stack trace:
#0 /includes/classes/observers/class.checkout_one_observer.php(685): OnePageCheckout->getTaxLocations()
#1 /includes/classes/traits/NotifierManager.php(106): checkout_one_observer->update(Object(notifier), 'ZEN_GET_TAX_LOC...', Array, false, NULL, NULL, NULL, NULL, NULL, NULL, NULL)
#2 /includes/functions/functions_taxes.php(355): base->notify('ZEN_GET_TAX_LOC...', Array, false)
#3 /includes/modules/order_total/ot_tax.php(66): zen_get_tax_locations()
#4 /includes/classes/order_total.php(229): ot_tax->process()
#5 /includes/modules/payment/paypalwpp.php(1637): order_total->pre_confirmation_check()
#6 /ipn_main_handler.php(81): paypalwpp->ec_step1()
#7 {main}
thrown in /includes/classes/OnePageCheckout.php on line 2568

[11-May-2026 15:08:12 America/New_York] Request URI: /ipn_main_handler.php?type=ec, IP address: xxx
--> PHP Fatal error: Uncaught Error: Typed property OnePageCheckout::$isVirtualOrder must not be accessed before initialization in /includes/classes/OnePageCheckout.php:2568
Stack trace:
#0 /includes/classes/observers/class.checkout_one_observer.php(685): OnePageCheckout->getTaxLocations()
#1 /includes/classes/traits/NotifierManager.php(106): checkout_one_observer->update(Object(notifier), 'ZEN_GET_TAX_LOC...', Array, false, NULL, NULL, NULL, NULL, NULL, NULL, NULL)
#2 /includes/functions/functions_taxes.php(355): base->notify('ZEN_GET_TAX_LOC...', Array, false)
#3 /includes/modules/order_total/ot_tax.php(66): zen_get_tax_locations()
#4 /includes/classes/order_total.php(229): ot_tax->process()
#5 /includes/modules/payment/paypalwpp.php(1637): order_total->pre_confirmation_check()
#6 /ipn_main_handler.php(81): paypalwpp->ec_step1()
#7 {main}
thrown in /includes/classes/OnePageCheckout.php on line 2568. 

Line 2568 is the following

"if ($this->isVirtualOrder === true || $this->getShippingBilling() === true) {"

The customer under this IP address has placed the order successfully (no sales tax was charged, which is also correct.) and he didn't order the virtual item.

[lat9]

Sigh, that's paypalwpp's "special checkout" mode coming in through the ipn_main_handler.php.

See this OPC GitHub issue with the correction: https://github.com/lat9/one_page_checkout/issues/463

[njcyx]

Thanks for your quick fix! I will try and let you know.

[njcyx]

Sorry, one more warning. We received an order using paypalwpp. The delivery address somehow was blank (hopefully only intermitent). We also received the following warning from OPC.

[12-May-2026 10:59:16 America/New_York] PHP Fatal error: Uncaught Error: Undefined constant "EMAIL_GREET_NONE" in /includes/modules/checkout_one_send_welcome_email.php:22
Stack trace:
#0 /includes/modules/pages/checkout_success/header_php_guest.php(43): require()
#1 /index.php(35): require('/home/...')
#2 {main}
thrown in /includes/modules/checkout_one_send_welcome_email.php on line 22

[12-May-2026 10:59:16 America/New_York] Request URI: /index.php?main_page=checkout_success&action=create_account, IP address: xxxx
--> PHP Fatal error: Uncaught Error: Undefined constant "EMAIL_GREET_NONE" in /includes/modules/checkout_one_send_welcome_email.php:22
Stack trace:
#0 /includes/modules/pages/checkout_success/header_php_guest.php(43): require()
#1 /index.php(35): require('/home/...')
#2 {main}
thrown in /includes/modules/checkout_one_send_welcome_email.php on line 22. 

Line 22 is the following

$email_text = sprintf(EMAIL_GREET_NONE, $firstname);

Update. It seems to be not related to paypalwpp. We received another normal order using paypaldp. It shows the delivery address as normal, but I receive the same warning.

[lat9]

Sorry, one more warning. We received an order using paypalwpp. The delivery address somehow was blank (hopefully only intermitent). We also received the following warning from OPC.

[12-May-2026 10:59:16 America/New_York] PHP Fatal error: Uncaught Error: Undefined constant "EMAIL_GREET_NONE" in /includes/modules/checkout_one_send_welcome_email.php:22
Stack trace:
#0 /includes/modules/pages/checkout_success/header_php_guest.php(43): require()
#1 /index.php(35): require('/home/...')
#2 {main}
thrown in /includes/modules/checkout_one_send_welcome_email.php on line 22

[12-May-2026 10:59:16 America/New_York] Request URI: /index.php?main_page=checkout_success&action=create_account, IP address: xxxx
--> PHP Fatal error: Uncaught Error: Undefined constant "EMAIL_GREET_NONE" in /includes/modules/checkout_one_send_welcome_email.php:22
Stack trace:
#0 /includes/modules/pages/checkout_success/header_php_guest.php(43): require()
#1 /index.php(35): require('/home/...')
#2 {main}
thrown in /includes/modules/checkout_one_send_welcome_email.php on line 22. 

Line 22 is the following

$email_text = sprintf(EMAIL_GREET_NONE, $firstname);

Update. It seems to be not related to paypalwpp. We received another normal order using paypaldp. It shows the delivery address as normal, but I receive the same warning.

It's "my bad" in v2.6.1. The create_account_send_email (and the associated constants' loading) was introduced in Zen Cart 2.2.x and you're using 2.1.0.

[lat9]

That "undefined constant" error has been noted and corrected via this GitHub issue: https://github.com/lat9/one_page_checkout/issues/464

[njcyx]

Thanks as always.

I have one more question. Regarding this file in OPC 2.6.1 \includes\templates\template_default\templates\tpl_order_status_default.php, it is the same stock file from zen cart 2.2.2/2.2.1. Can we use it for the early zen carts such as my zen cart 2.1.0?

[lat9]

Thanks as always.

I have one more question. Regarding this file in OPC 2.6.1 \includes\templates\template_default\templates\tpl_order_status_default.php, it is the same stock file from zen cart 2.2.2/2.2.1. Can we use it for the early zen carts such as my zen cart 2.1.0?

Using for zc210 should be just fine, but make sure that you're using the version of /includes/modules/pages/order_status/header_php.php that ships with OPC v2.6.1.

[njcyx]

Ok, thanks.