Shopify/active_merchant — pull request #511 by moklett (2012-11-27 01:31:13+00:00)
Title: PaymentExpress: Add support for optional fields: ClientType and TxnData

Even though not documented for PxPost (it is documented for WebService), the ClientType element on transactions can affect the way PaymentExpress submits transaction to the acquirers.

This commit gives control over that element through the `:client_type` element in the options hash.

For completeness, access has also been given to the remaining optional elements: `TxnData1`, `TxnData2`, and `TxnData3`, which can be set via `:txn_data1`, `:txn_data2`, and `:txn_data2`, respectively, in the options hash.