This is more of a set of modifications rather than an actual module, but the end result is the same.

First thing you’ll need to do is backup your existing site and database. I’d recommend using a test install of Xcart so that nothing in production gets messed up. With that in mind, the first step is to alter the pricing table by using the following alter table command. If you have a different version of MySQL, you might need to tweak this a bit.

ALTER TABLE `xcart_pricing` ADD COLUMN `numpymnts` INTEGER UNSIGNED NOT NULL DEFAULT 1,
ADD COLUMN `paymentprice` DECIMAL(12,2) NOT NULL DEFAULT 0 AFTER `numpymnts`,
ADD COLUMN `sourceproductcode` VARCHAR(255) DEFAULT 0 AFTER `paymentprice`,
ADD COLUMN `sortby` INTEGER UNSIGNED NOT NULL DEFAULT 0 AFTER `sourceproductcode`,
ADD COLUMN `mastervariant` SMALLINT(5) UNSIGNED NOT NULL DEFAULT 0 AFTER `sortby`,
ADD COLUMN `price_override` SMALLINT(5) UNSIGNED NOT NULL DEFAULT 0 AFTER `mastervariant`,
ADD INDEX `numpymnts`(`numpymnts`),
ADD INDEX `paymentprice`(`paymentprice`),
ADD INDEX `sortby`(`sortby`),
ADD INDEX `sourceproductcode`(`sourceproductcode`),
ADD INDEX `mastervariant`(`mastervariant`),
ADD INDEX `price_override`(`price_override`)
, ENGINE = MyISAM;

The new columns are as follows:
numpyments = number of payments
paymentprice = price the export expects to see (might be one payment or the total)
sourceproductcode = product code (sku) that export expects to see
sortby = the order in which the variants show up on the admin page
mastervariant = overrides the ’starting at’ price
price_override = use this table for the price instead of the orders table for reporting

Next, you’ll need to modify some of the admin template files, such as:

Modify Files:
/skin1/modules/Product_Options/product_variants.tpl - add fields to the variants html table - don’t add the price_override column.

/modules/Product_Options/func. php - edit func_get_product_variants and add in the columns that were added to the product_variants.tpl file

When you submit the variants, the form goes to:

product_modify.php
section=variants
mode = product_variants_modify
productid = [variable]
submode = “data”
geid = “”

Once sumbitted, the code is run in this ELSEIF block in modules/Product_Options/product_variants.php:
} elseif ($mode == ‘product_variants_modify’ && $vs && $submode != ‘prices’) {

In here, you need to edit the $query_price_data array to include the additional fields; for example:

## BB Edit - added additional fields
$query_price_data = array(
"price" => $v['price'],
"variantid" => $k,
"productid" => $productid,
"quantity" => 1,
"membershipid" => 0,
"numpymnts" => $v['numpymnts'],
"paymentprice" => $v['paymentprice'],
"sortby" => $v['sortby'],
"sourceproductcode" => $v['sourceproductcode'],
"mastervariant" => $v['mastervariant']
);

Next, you need to edit the modify options page, otherwise, if you change options, it’ll remove your new field data.

When submitting this form, it passes these variables to product_modify.php:

section=options
mode=product_options_add
classid= your classid
productid = your productid
geid=”"

If you change add[is_modifier] (price modifier = ‘y’, else it’s blank), it rebuilds the variants by calling func_rebuild_variants in modules/Product_Options/func.php

//Rebuild variants: . . . . product_modify.php?productid=18&section=options&classid=71

In func_rebuild_variants, change the $_product[’prices’] $data variable to:

$data = array(
"productid" => $productid,
"quantity" => $p['quantity'],
"membershipid" => $p['membershipid'],
"variantid" => $variantid,
"price" => $p['price'],
"numpymnts" => $p['numpymnts'],
"paymentprice" => $p['paymentprice'],
"sortby" => $p['sortby'],
"sourceproductcode" => $p['sourceproductcode'],
"mastervariant" => $p['mastervariant']
);

This will keep your data from being lost in the new columns. And that’s it, as far as back end functionality for the multi pay option. Depending on how your templates are set up, you’ll probably want to use the new columns to force the “mastervariant” column to show up in the “starting at” price. Do this by ordering that query by mastervariant in descending order. The rest of the columns really come in handy when you need to see the full price such as in reports, modifying omniture code, and to produce export files where the fulfillment company wants to see the full amount instead of the per payment price.