Added support for custom lookup parameters. Issue #12.

carton/cart.py

@@ -1,5 +1,7 @@
 from decimal import Decimal
 
+from django.conf import settings
+
 from carton import module_loading
 from carton import settings as carton_settings
 
@@ -61,9 +63,20 @@ def __contains__(self, product):
     def get_product_model(self):
         return module_loading.get_product_model()
 
+    def filter_products(self, queryset):
+        """
+        Applies lookup parameters defined in settings.
+        """
+        lookup_parameters = getattr(settings, 'CART_PRODUCT_LOOKUP', None)
+        if lookup_parameters:
+            queryset = queryset.filter(**lookup_parameters)
+        return queryset
+
     def get_queryset(self):
         product_model = self.get_product_model()
-        return product_model._default_manager.all()
+        queryset = product_model._default_manager.all()
+        queryset = self.filter_products(queryset)
+        return queryset
 
     def update_session(self):
         """

carton/tests/tests.py

@@ -1,8 +1,12 @@
 from django.core.urlresolvers import reverse
 from django.test import TestCase
-
 from carton.tests.models import Product
 
+try:
+    from django.test import override_settings
+except ImportError:
+    from  django.test.utils import override_settings
+
 
 class CartTests(TestCase):
 
@@ -99,3 +103,15 @@ def test_cart_items_are_cleared(self):
         response = self.client.get(self.url_show)
         self.assertNotContains(response, 'deer')
         self.assertNotContains(response, 'moose')
+
+    @override_settings(CART_PRODUCT_LOOKUP={'price__gt': 1})
+    def test_custom_product_filter_are_applied(self):
+        # We modify the queryset to exclude some products. For these excluded
+        # we should not be able to add them in the cart.
+        exclude = Product.objects.create(name='EXCLUDE', price=0.99, custom_id=100)
+        exclude_data = {'product_id': exclude.pk}
+        self.client.post(self.url_add, self.deer_data)
+        self.client.post(self.url_add, exclude_data)
+        response = self.client.get(self.url_show)
+        self.assertNotContains(response, 'EXCLUDE')
+        self.assertContains(response, 'deer')