make possible to reuse get_change_price()

plans/plan_change.py

@@ -1,5 +1,7 @@
 # coding=utf-8
 from decimal import Decimal
+from django.conf import settings
+from plans.importer import import_name
 
 
 class PlanChangePolicy(object):
@@ -96,3 +98,24 @@ def _calculate_final_price(self, period, day_cost_diff):
             return None
         else:
             return cost
+
+
+def get_policy():
+    policy_class = getattr(
+        settings,
+        "PLANS_CHANGE_POLICY",
+        "plans.plan_change.StandardPlanChangePolicy",
+    )
+    return import_name(policy_class)()
+
+
+def get_change_price(userplan, plan):
+    policy = get_policy()
+
+    if userplan.expire is not None:
+        period = userplan.days_left()
+    else:
+        # Use the default period of the new plan
+        period = 30
+
+    return policy.get_change_price(userplan.plan, plan, period)

plans/views.py

@@ -40,6 +40,7 @@
 from plans.signals import order_started
 from plans.utils import get_currency
 from plans.validators import plan_validation
+from plans.plan_change import get_change_price
 
 UserPlan = AbstractUserPlan.get_concrete_model()
 PlanPricing = AbstractPlanPricing.get_concrete_model()
@@ -340,27 +341,8 @@ def get_all_context(self):
         )
         self.pricing = None
 
-    def get_policy(self):
-        policy_class = getattr(
-            settings,
-            "PLANS_CHANGE_POLICY",
-            "plans.plan_change.StandardPlanChangePolicy",
-        )
-        return import_name(policy_class)()
-
     def get_price(self):
-        policy = self.get_policy()
-        userplan = self.request.user.userplan
-
-        if userplan.expire is not None:
-            period = self.request.user.userplan.days_left()
-        else:
-            # Use the default period of the new plan
-            period = 30
-
-        return policy.get_change_price(
-            self.request.user.userplan.plan, self.plan, period
-        )
+        return get_change_price(self.request.user.userplan, self.plan)
 
     def get_context_data(self, **kwargs):
         context = super(CreateOrderView, self).get_context_data(**kwargs)