WIP filters: when invalid filter value, use default value if there is one

adhocracy4/filters/filters.py

@@ -63,6 +63,11 @@ def __init__(self, data, *args, **kwargs):
                 data[key] = value
         super().__init__(data, *args, **kwargs)
 
+        # if filter has invalid value, set it to default value
+        for field in self.form.errors:
+            if field in self.data and field in self.defaults:
+                self.data[field] = self.defaults[field]
+
 
 class DistinctOrderingFilter(django_filters.OrderingFilter):
     """Makes sure, that every queryset gets a distinct ordering.

tests/filter/test_defaults_filterset.py

@@ -0,0 +1,76 @@
+import pytest
+from dateutil.parser import parse
+
+from adhocracy4.filters.filters import DefaultsFilterSet
+from adhocracy4.filters.filters import DynamicChoicesOrderingFilter
+from adhocracy4.filters.views import FilteredListView
+from tests.apps.questions import models as question_models
+
+
+class ExampleDefaultsFilterSet(DefaultsFilterSet):
+    defaults = {
+        'ordering': '-created'
+    }
+    ordering = DynamicChoicesOrderingFilter(
+        choices=(('-positive_rating_count', 'Most popular'),
+                 ('-comment_count', 'Most commented'),
+                 ('-created', 'Most recent'))
+
+    )
+
+    class Meta:
+        model = question_models.Question
+        fields = ['ordering']
+
+
+@pytest.fixture
+def question_list_view():
+    class DummyView(FilteredListView):
+        model = question_models.Question
+        filter_set = ExampleDefaultsFilterSet
+    return DummyView.as_view()
+
+
+@pytest.mark.django_db
+def test_ordering_filter_default(rf, question_list_view, project,
+                                 question_factory, comment_factory):
+    q1 = question_factory(created=parse('2018-01-01 7:00:00 UTC'))
+    q2 = question_factory(created=parse('2019-01-01 7:00:00 UTC'))
+    q3 = question_factory(created=parse('2020-01-01 7:00:00 UTC'))
+    q4 = question_factory(created=parse('2021-01-01 7:00:00 UTC'))
+    comment_factory(content_object=q1)
+    comment_factory(content_object=q2)
+    comment_factory(content_object=q2)
+    comment_factory(content_object=q3)
+
+    request = rf.get('/questions')
+    response = question_list_view(request, project=project)
+    question_list = response.context_data['question_list']
+    assert question_list[0] == q4
+    assert question_list[1] == q3
+    assert question_list[2] == q2
+    assert question_list[3] == q1
+
+    request = rf.get('/questions?ordering=')
+    response = question_list_view(request, project=project)
+    question_list = response.context_data['question_list']
+    assert question_list[0] == q1
+    assert question_list[1] == q2
+    assert question_list[2] == q3
+    assert question_list[3] == q4
+
+    request = rf.get('/questions?ordering=invalid_choice')
+    response = question_list_view(request, project=project)
+    question_list = response.context_data['question_list']
+    assert question_list[0] == q4
+    assert question_list[1] == q3
+    assert question_list[2] == q2
+    assert question_list[3] == q1
+
+    request = rf.get('/questions?ordering=-comment_count')
+    response = question_list_view(request, project=project)
+    question_list = response.context_data['question_list']
+    assert question_list[0] == q2
+    assert question_list[1] == q1
+    assert question_list[2] == q3
+    assert question_list[3] == q4