Add a self description attribute to payment backend

Add first example to spplus backend.

eopayment/__init__.py

@@ -11,13 +11,14 @@ __version__ = "0.0.1"
 SIPS = 'sips'
 SYSTEMPAY = 'systempayv2'
 SPPLUS = 'spplus'
+DUMMY = 'dummy'
 
 class Payment(object):
     '''
        Interface to credit card online payment servers of French banks. The
        only use case supported for now is a unique automatic payment.
 
-           >>> import eopayment
+           >>> from eopayment import Payment, SPPLUS
            >>> spplus_options = {
                    'cle': '58 6d fc 9c 34 91 9b 86 3f fd 64 ' +
                           '63 c9 13 4a 26 ba 29 74 1e c7 e9 80 79',
@@ -29,7 +30,7 @@ class Payment(object):
            ('ZYX0NIFcbZIDuiZfazQp', 1, 'https://www.spplus.net/paiement/init.do?devise=978&validite=23%2F04%2F2011&version=1&reference=ZYX0NIFcbZIDuiZfazQp&montant=10.00&siret=00000000000001-01&langue=FR&taxe=0.00&email=bob%40example.com&hmac=b43dce98f97e5d249ef96f7f31d962f8fa5636ff')
 
        Supported backend of French banks are:
-       
+
         - sips, for BNP, Banque Populaire (before 2010), CCF, HSBC, Crédit
           Agricole, La Banque Postale, LCL, Société Générale and Crédit du
           Nord.
@@ -40,12 +41,23 @@ class Payment(object):
        executables, request and response, as the protocol from ATOS/SIPS is not
        documented. For the other backends the modules are autonomous.
 
+       Each backend need some configuration parameters to be used, the
+       description of the backend list those parameters. The description
+       dictionary can be used to generate configuration forms.
+
+           >>> d = eopayment.Payment.get_backend(SPPLUS).description
+           >>> print d['caption']
+           SSPPlus payment service of French bank Caisse d'epargne
+           >>> print d['parameters'].keys()
+           ('cle','siret')
+           >>> print d['parameters']['cle']['caption']
+           Secret Key
+
     '''
 
     def __init__(self, kind, options):
         self.kind = kind
-        module = __import__(kind)
-        self.backend = module.Payment(options)
+        self.backend = Payment.get_backend(kind)(options)
 
     def request(self, amount, email=None, next_url=None):
         '''Request a payment to the payment backend.
@@ -115,6 +127,11 @@ class Payment(object):
         '''
         return self.backend.response(query_string)
 
+    @classmethod
+    def get_backend(cls, kind):
+        module = __import__(kind)
+        return module.Payment
+
 if __name__ == '__main__':
     logging.basicConfig(level=logging.DEBUG)
     spplus_options = {

eopayment/spplus.py

@@ -7,6 +7,7 @@ import urllib
 import string
 import datetime as dt
 import logging
+import re
 
 import Crypto.Cipher.DES
 from common import PaymentCommon, URL
@@ -51,6 +52,21 @@ SERVICE_URL = "https://www.spplus.net/paiement/init.do"
 LOGGER = logging.getLogger(__name__)
 
 class Payment(PaymentCommon):
+    description = {
+            'caption': "SPPlus payment service of French bank Caisse d'epargne",
+            'parameters': {
+                'cle': {
+                    'caption': 'Secret key, a 40 digits hexadecimal number',
+                    'regexp': re.compile('^ *((?:[a-fA-F0-9] *){40}) *$')
+                },
+                'siret': {
+                    'caption': 'Siret of the entreprise augmented with the '
+                        'site number, example: 00000000000001-01',
+                    'regexp': re.compile('^ *(\d{14}-\d{2}) *$')
+                }
+            }
+    }
+
     def __init__(self, options):
         LOGGER.debug('initializing spplus payment with %s' % options)
         self.cle = options['cle']
@@ -100,7 +116,7 @@ next_url=%s' % (montant, email, next_url))
                 signed_data, signature = query_string.rsplit('&', 1)
                 _, hmac = signature.split('=', 1)
                 LOGGER.debug('got signature %s' % hmac)
-                computed_hmac = sign_ntkey_query(self.clem, signed_data)
+                computed_hmac = sign_ntkey_query(self.cle, signed_data)
                 LOGGER.debug('computed signature %s' % hmac)
                 result = hmac==computed_hmac \
                         and reference.get(ETAT) == ETAT_PAIEMENT_ACCEPTE