Interaction with Other Modules

The following is a list of some commonly installed 3rd party Zen Cart modules (plugins) known to be compatible with Edit Orders. The list is mainly confined to 3rd party plugins which also affect customer orders or placing customer orders. Please refer to the appropriate module for further notes and instructions (if any).

Order-total modules are used to change the total cost of an order. Edit Orders uses the same order-total modules as the storefront checkout process. Most of the order-total modules which ship with Zen Cart have been validated and work as expected (ot_coupon, ot_gv, ot_loworderfee, ot_shipping, ot_subtotal, ot_tax and ot_total). Both ot_subtotal and ot_total must be enabled for Edit Orders to function correctly.

Order-Total Modules: Changes Required

If an order-total module requires a form-input, that module will require changes for use with Edit Orders⁵. Specifically, an order-total must:

1. Declare itself as a credit_class module.
2. Include a publicly-scoped array named eoInfo. This array enables EO to communicate with the order-total regarding the total's inclusion in the order as well as the total's current title and value.

public array $eoInfo;

public function __construct()
{
    ...
        
    $this->eoInfo = [
        'installed' => false,
        'title' => $this->title,
        'value' => 0,
    ]
}

You can refer to the ot_misc_cost.php and ot_onetime_discount.php order totals that are part of the Edit Orders distribution as well as ot_priority_handling, v2.0.0 or later, for examples of the usage.

Local Sales Tax

Edit Orders has been validated with Local Sales Tax v3.0.0 or later; previous versions are not supported.

Other Modules (Troubleshooting)

Because Edit Orders loads the same order-total modules as the storefront checkout process, all enabled modules must be able to be loaded and processed from the store's Zen Cart admin-console. Because Zen Cart traditionally does not use those modules during admin-level processing, many 3rd-party order-total modules were designed without the authors taking this into consideration.

The most common symptom caused by a problematic order-total module (when editing an order) is the presentation of a "blank" page when adding a product to (or updating) the order. In most cases taking a look at the generated debug log provides valuable insight as to how to correct the underlying issue. Another option is to disable all add-on order-total modules and then enable them one-by-one to determine which order-total module is causing the blank page.

Here are some common causes of issues with 3rd-party order-total modules and possible corrective actions:

1. The order-total's installation includes additional storefront functions.
   • Copy the order-total's function file(s) to your store's /YOUR_ADMIN/includes/functions/extra_functions directory.
2. The order-total has not been updated for use with EO⁵.