Added seperate method to change user's credit and create a transaction

cash/models.py

@@ -27,6 +27,16 @@ class Account(models.Model):
 				instance.account.card_number = instance.ldap_user.attrs['employeenumber'][0]
 				instance.account.save()
 
+	def change_credit(amount, subject, desc):
+		self.credit -= amount
+		self.save()
+
+		transaction = Transaction(account=self, subject=subject,
+								  amount=(-amount), description=desc)
+		transaction.save()
+
+		
+
 	def buy_products(self, products):
 		# TODO place it somewhere else
 		MAX_DEBIT = -3500
@@ -37,10 +47,7 @@ class Account(models.Model):
 
 		total_value = sum(map(lambda p: p.price * products[p], products.keys()))
 		if self.credit - total_value >= MAX_DEBIT:
-			self.credit -= total_value
-			self.save()
-
-			descr = ''
+			desc = ''
 			for product in products.keys():
 				amount = products[product]
 
@@ -48,12 +55,9 @@ class Account(models.Model):
 				                         count=amount, unit_price=product.price)
 				logentry.save()
 
-				descr += '%dx %s\n' % (amount, product.name)
-
-			transaction = Transaction(account=self, subject=BUY_SUBJECT,
-			                          amount=(-total_value), description=descr)
-			transaction.save()
+				desc += '%dx %s\n' % (amount, product.name)
 
+				self.change_credit(total_value, BUY_SUBJECT, desc)
 			return True
 		else:
 			return False