Tax Calculation for Product Attribute combinations

Hi

im developing custom Tax Calculator plugin which is base don NopCommerce's Nop.Plugin.Tax.CountryStateZip  Plugin

Here is my senario

I have a product lets say SKU = ABC. ( for us this is Style) where my inventory is managed by products attributes

so i have 2 product combination which,

1. Color : Gold / Size : 10   ( SKU = ABC001 )
2. Color : White/ Size : 15   ( SKU = ABC002 )

when nopcommerce calls  my plugin's

GetTaxRate(CalculateTaxRequest calculateTaxRequest)

Method,i expect nop Core system to pass me the Product SKU as  'ABC001' or 'ABC002' according to attribute selection.

however it is passing 'ABC' instead. therefor i can not identify which attribute combination user have selected.

My Tax rates are based on Individual SKU. ( 'ABC001' or 'ABC002' )

is there anyway i can overcome this issue?

Please note that i do not wish to Change the NOP Core System. just want to extend the functionality through my plugin.


thank you very much !!
Charith Wickramasinghe