If you want get multiple statement_lines.Then you have to follow the following code in your .py file.

import logging

import sets



from openerp import models, fields, api



_logger = logging.getLogger(__name__)



class barcode_rule(models.Model):

_inherit = 'barcode.rule'



def _get_type_selection(self):

types = sets.Set(super(barcode_rule, self)._get_type_selection())

types.update([

('credit', 'Credit Card')

])

return list(types)











mercury_card_number = fields.Char(string='Card Number', help='The last 4 numbers of the card used to pay')

mercury_prefixed_card_number = fields.Char(string='Card Number', compute='_compute_prefixed_card_number', help='The card number used for the payment.')

mercury_card_brand = fields.Char(string='Card Brand', help='The brand of the payment card (e.g. Visa, AMEX, ...)')

mercury_card_owner_name = fields.Char(string='Card Owner Name', help='The name of the card owner')

mercury_ref_no = fields.Char(string='Mercury reference number', help='Payment reference number from Mercury Pay')

mercury_record_no = fields.Char(string='Mercury record number', help='Payment record number from Mercury Pay')

mercury_invoice_no = fields.Integer(string='Mercury invoice number', help='Invoice number from Mercury Pay')



@api.one

def _compute_prefixed_card_number(self):

if self.mercury_card_number:

self.mercury_prefixed_card_number = "********" + self.mercury_card_number

else:

self.mercury_prefixed_card_number = ""



class account_journal(models.Model):

_inherit = 'account.journal'



pos_mercury_config_id = fields.Many2one('pos_mercury.configuration', string='Mercury configuration', help='The configuration of Mercury used for this journal')



class pos_order_card(models.models):

_inherit = "pos.order"



@api.model

def _payment_fields(self, ui_paymentline):

fields = super(pos_order_card, self)._payment_fields(ui_paymentline)



fields.update({

'card_number': ui_paymentline.get('mercury_card_number'),

'card_brand': ui_paymentline.get('mercury_card_brand'),

'card_owner_name': ui_paymentline.get('mercury_card_owner_name'),

'ref_no': ui_paymentline.get('mercury_ref_no'),

'record_no': ui_paymentline.get('mercury_record_no'),

'invoice_no': ui_paymentline.get('mercury_invoice_no')

})



return fields



@api.model

def add_payment(self, order_id, data):

statement_id = super(pos_order_card, self).add_payment(order_id, data)

statement_lines = self.env['account.bank.statement.line'].search([('statement_id', '=', statement_id),

('pos_statement_id', '=', order_id),

('journal_id', '=', data['journal']),

('amount', '=', data['amount'])])



# we can get multiple statement_lines when there are >1 credit

# card payments with the same amount. In that case it doesn't

# matter which statement line we pick, just pick one that

# isn't already used.

for line in statement_lines:

if not line.mercury_card_brand:

line.mercury_card_brand = data.get('card_brand')

line.mercury_card_number = data.get('card_number')

line.mercury_card_owner_name = data.get('card_owner_name')



line.mercury_ref_no = data.get('ref_no')

line.mercury_record_no = data.get('record_no')

line.mercury_invoice_no = data.get('invoice_no')



break



return statement_id