Merge pull request chibisov#75 from alexander-akhmetov/sql_queryset

fix queryset.query.__str__() with EmptyResultSet

docs/index.md

@@ -2172,6 +2172,7 @@ You can read about versioning, deprecation policy and upgrading from
 
 #### Development version
 
+* Fixed `ListSqlQueryKeyBit` and `RetrieveSqlQueryKeyBit` [problems](https://github.com/chibisov/drf-extensions/issues/28) with `EmptyResultSet` exception ([pull](https://github.com/chibisov/drf-extensions/pull/75/)).
 * All items are now by default in [ArgsKeyBit](#argskeybit), [KwargsKeyBit](#kwargskeybit) and [QueryParamsKeyBit](#queryparamskeybit)
 
 #### 0.2.7

rest_framework_extensions/key_constructor/bits.py

@@ -1,6 +1,8 @@
 # -*- coding: utf-8 -*-
 from django.utils.translation import get_language
 from django.db.models.query import EmptyQuerySet
+from django.db.models.sql.datastructures import EmptyResultSet
+
 from rest_framework_extensions.compat import force_text
 
 
@@ -176,28 +178,34 @@ def get_data(self, **kwargs):
         return super(PaginationKeyBit, self).get_data(**kwargs)
 
 
-class ListSqlQueryKeyBit(KeyBitBase):
-    def get_data(self, params, view_instance, view_method, request, args, kwargs):
-        queryset = view_instance.filter_queryset(view_instance.get_queryset())
+class SqlQueryKeyBitBase(KeyBitBase):
+    def _get_queryset_query_string(self, queryset):
         if isinstance(queryset, EmptyQuerySet):
             return None
         else:
-            return force_text(queryset.query.__str__())
+            try:
+                return force_text(queryset.query.__str__())
+            except EmptyResultSet:
+                return None
+
+
+class ListSqlQueryKeyBit(SqlQueryKeyBitBase):
+    def get_data(self, params, view_instance, view_method, request, args, kwargs):
+        queryset = view_instance.filter_queryset(view_instance.get_queryset())
+        return self._get_queryset_query_string(queryset)
 
 
-class RetrieveSqlQueryKeyBit(KeyBitBase):
+class RetrieveSqlQueryKeyBit(SqlQueryKeyBitBase):
     def get_data(self, params, view_instance, view_method, request, args, kwargs):
         lookup_value = view_instance.kwargs[view_instance.lookup_field]
         try:
             queryset = view_instance.filter_queryset(view_instance.get_queryset()).filter(
                 **{view_instance.lookup_field: lookup_value}
             )
-            if isinstance(queryset, EmptyQuerySet):
-                return None
-            else:
-                return force_text(queryset.query.__str__())
         except ValueError:
             return None
+        else:
+            return self._get_queryset_query_string(queryset)
 
 
 class ArgsKeyBit(AllArgsMixin, KeyBitBase):

tests_app/tests/unit/key_constructor/bits/tests.py

@@ -404,6 +404,11 @@ def test_should_return_none_if_empty_queryset(self):
         response = ListSqlQueryKeyBit().get_data(**self.kwargs)
         self.assertEqual(response, None)
 
+    def test_should_return_none_if_empty_result_set_raised(self):
+        self.kwargs['view_instance'].filter_queryset = lambda x: x.filter(pk__in=[])
+        response = ListSqlQueryKeyBit().get_data(**self.kwargs)
+        self.assertEqual(response, None)
+
 
 class RetrieveSqlQueryKeyBitTest(TestCase):
     def setUp(self):
@@ -443,6 +448,11 @@ def test_should_return_none_if_empty_queryset(self):
         response = RetrieveSqlQueryKeyBit().get_data(**self.kwargs)
         self.assertEqual(response, None)
 
+    def test_should_return_none_if_empty_result_set_raised(self):
+        self.kwargs['view_instance'].filter_queryset = lambda x: x.filter(pk__in=[])
+        response = RetrieveSqlQueryKeyBit().get_data(**self.kwargs)
+        self.assertEqual(response, None)
+
 
 class ArgsKeyBitTest(TestCase):
     def setUp(self):