Add enum support to filters and fix filter typing (v3) (#1119)

* - Add filtering support for choice fields converted to graphql Enum (or not)
- Fix type of various filters (used to default to String)
- Fix bug with contains introduced in previous PR
- Fix bug with declared filters being overridden (see PR #1108)
- Fix support for ArrayField and add documentation

* Fix for v3

Co-authored-by: Thomas Leonard <thomas@loftorbital.com>

docs/filtering.rst

@@ -258,3 +258,46 @@ with this set up, you can now order the users under group:
         }
       }
     }
+
+
+PostgreSQL `ArrayField`
+-----------------------
+
+Graphene provides an easy to implement filters on `ArrayField` as they are not natively supported by django_filters:
+
+.. code:: python
+
+    from django.db import models
+    from django_filters import FilterSet, OrderingFilter
+    from graphene_django.filter import ArrayFilter
+
+    class Event(models.Model):
+        name = models.CharField(max_length=50)
+        tags = ArrayField(models.CharField(max_length=50))
+
+    class EventFilterSet(FilterSet):
+        class Meta:
+            model = Event
+            fields = {
+                "name": ["exact", "contains"],
+            }
+
+        tags__contains = ArrayFilter(field_name="tags", lookup_expr="contains")
+        tags__overlap = ArrayFilter(field_name="tags", lookup_expr="overlap")
+        tags = ArrayFilter(field_name="tags", lookup_expr="exact")
+
+    class EventType(DjangoObjectType):
+        class Meta:
+            model = Event
+            interfaces = (Node,)
+            filterset_class = EventFilterSet
+
+with this set up, you can now filter events by tags:
+
+.. code::
+
+    query {
+      events(tags_Overlap: ["concert", "festival"]) {
+        name
+      }
+    }

graphene_django/converter.py

@@ -35,7 +35,7 @@
 
 
 class BlankValueField(Field):
-    def get_resolver(self, parent_resolver):
+    def wrap_resolve(self, parent_resolver):
         resolver = self.resolver or parent_resolver
 
         # create custom resolver

graphene_django/filter/__init__.py

@@ -9,10 +9,19 @@
     )
 else:
     from .fields import DjangoFilterConnectionField
-    from .filters import GlobalIDFilter, GlobalIDMultipleChoiceFilter
+    from .filters import (
+        ArrayFilter,
+        GlobalIDFilter,
+        GlobalIDMultipleChoiceFilter,
+        ListFilter,
+        RangeFilter,
+    )
 
     __all__ = [
         "DjangoFilterConnectionField",
         "GlobalIDFilter",
         "GlobalIDMultipleChoiceFilter",
+        "ArrayFilter",
+        "ListFilter",
+        "RangeFilter",
     ]

graphene_django/filter/fields.py

@@ -2,12 +2,31 @@
 from functools import partial
 
 from django.core.exceptions import ValidationError
+
+from graphene.types.enum import EnumType
 from graphene.types.argument import to_arguments
 from graphene.utils.str_converters import to_snake_case
+
 from ..fields import DjangoConnectionField
 from .utils import get_filtering_args_from_filterset, get_filterset_class
 
 
+def convert_enum(data):
+    """
+    Check if the data is a enum option (or potentially nested list of enum option)
+    and convert it to its value.
+
+    This method is used to pre-process the data for the filters as they can take an
+    graphene.Enum as argument, but filters (from django_filters) expect a simple value.
+    """
+    if isinstance(data, list):
+        return [convert_enum(item) for item in data]
+    if isinstance(type(data), EnumType):
+        return data.value
+    else:
+        return data
+
+
 class DjangoFilterConnectionField(DjangoConnectionField):
     def __init__(
         self,
@@ -43,8 +62,8 @@ def filterset_class(self):
             if self._extra_filter_meta:
                 meta.update(self._extra_filter_meta)
 
-            filterset_class = self._provided_filterset_class or (
-                self.node_type._meta.filterset_class
+            filterset_class = (
+                self._provided_filterset_class or self.node_type._meta.filterset_class
             )
             self._filterset_class = get_filterset_class(filterset_class, **meta)
 
@@ -68,7 +87,7 @@ def filter_kwargs():
                 if k in filtering_args:
                     if k == "order_by" and v is not None:
                         v = to_snake_case(v)
-                    kwargs[k] = v
+                    kwargs[k] = convert_enum(v)
             return kwargs
 
         qs = super(DjangoFilterConnectionField, cls).resolve_queryset(
@@ -78,7 +97,7 @@ def filter_kwargs():
         filterset = filterset_class(
             data=filter_kwargs(), queryset=qs, request=info.context
         )
-        if filterset.form.is_valid():
+        if filterset.is_valid():
             return filterset.qs
         raise ValidationError(filterset.form.errors.as_json())
 

graphene_django/filter/filters.py

@@ -2,6 +2,7 @@
 from django.forms import Field
 
 from django_filters import Filter, MultipleChoiceFilter
+from django_filters.constants import EMPTY_VALUES
 
 from graphql_relay.node.node import from_global_id
 
@@ -31,14 +32,15 @@ def filter(self, qs, value):
         return super(GlobalIDMultipleChoiceFilter, self).filter(qs, gids)
 
 
-class InFilter(Filter):
+class ListFilter(Filter):
     """
-    Filter for a list of value using the `__in` Django filter.
+    Filter that takes a list of value as input.
+    It is for example used for `__in` filters.
     """
 
     def filter(self, qs, value):
         """
-        Override the default filter class to check first weather the list is
+        Override the default filter class to check first whether the list is
         empty or not.
         This needs to be done as in this case we expect to get an empty output
         (if not an exclude filter) but django_filter consider an empty list
@@ -73,3 +75,27 @@ class RangeField(Field):
 
 class RangeFilter(Filter):
     field_class = RangeField
+
+
+class ArrayFilter(Filter):
+    """
+    Filter made for PostgreSQL ArrayField.
+    """
+
+    def filter(self, qs, value):
+        """
+        Override the default filter class to check first whether the list is
+        empty or not.
+        This needs to be done as in this case we expect to get the filter applied with
+        an empty list since it's a valid value but django_filter consider an empty list
+        to be an empty input value (see `EMPTY_VALUES`) meaning that
+        the filter does not need to be applied (hence returning the original
+        queryset).
+        """
+        if value in EMPTY_VALUES and value != []:
+            return qs
+        if self.distinct:
+            qs = qs.distinct()
+        lookup = "%s__%s" % (self.field_name, self.lookup_expr)
+        qs = self.get_method(qs)(**{lookup: value})
+        return qs

graphene_django/filter/tests/conftest.py

@@ -9,6 +9,7 @@
 from graphene.relay import Node
 from graphene_django import DjangoObjectType
 from graphene_django.utils import DJANGO_FILTER_INSTALLED
+from graphene_django.filter import ArrayFilter, ListFilter
 
 from ...compat import ArrayField
 
@@ -27,49 +28,61 @@
 STORE = {"events": []}
 
 
-@pytest.fixture
-def Event():
-    class Event(models.Model):
-        name = models.CharField(max_length=50)
-        tags = ArrayField(models.CharField(max_length=50))
-
-    return Event
+class Event(models.Model):
+    name = models.CharField(max_length=50)
+    tags = ArrayField(models.CharField(max_length=50))
+    tag_ids = ArrayField(models.IntegerField())
+    random_field = ArrayField(models.BooleanField())
 
 
 @pytest.fixture
-def EventFilterSet(Event):
-
-    from django.contrib.postgres.forms import SimpleArrayField
-
-    class ArrayFilter(filters.Filter):
-        base_field_class = SimpleArrayField
-
+def EventFilterSet():
     class EventFilterSet(FilterSet):
         class Meta:
             model = Event
             fields = {
-                "name": ["exact"],
+                "name": ["exact", "contains"],
             }
 
+        # Those are actually usable with our Query fixture bellow
         tags__contains = ArrayFilter(field_name="tags", lookup_expr="contains")
         tags__overlap = ArrayFilter(field_name="tags", lookup_expr="overlap")
+        tags = ArrayFilter(field_name="tags", lookup_expr="exact")
+
+        # Those are actually not usable and only to check type declarations
+        tags_ids__contains = ArrayFilter(field_name="tag_ids", lookup_expr="contains")
+        tags_ids__overlap = ArrayFilter(field_name="tag_ids", lookup_expr="overlap")
+        tags_ids = ArrayFilter(field_name="tag_ids", lookup_expr="exact")
+        random_field__contains = ArrayFilter(
+            field_name="random_field", lookup_expr="contains"
+        )
+        random_field__overlap = ArrayFilter(
+            field_name="random_field", lookup_expr="overlap"
+        )
+        random_field = ArrayFilter(field_name="random_field", lookup_expr="exact")
 
     return EventFilterSet
 
 
 @pytest.fixture
-def EventType(Event, EventFilterSet):
+def EventType(EventFilterSet):
     class EventType(DjangoObjectType):
         class Meta:
             model = Event
             interfaces = (Node,)
+            fields = "__all__"
             filterset_class = EventFilterSet
 
     return EventType
 
 
 @pytest.fixture
-def Query(Event, EventType):
+def Query(EventType):
+    """
+    Note that we have to use a custom resolver to replicate the arrayfield filter behavior as
+    we are running unit tests in sqlite which does not have ArrayFields.
+    """
+
     class Query(graphene.ObjectType):
         events = DjangoFilterConnectionField(EventType)
 
@@ -79,6 +92,7 @@ def resolve_events(self, info, **kwargs):
                 Event(name="Live Show", tags=["concert", "music", "rock"],),
                 Event(name="Musical", tags=["movie", "music"],),
                 Event(name="Ballet", tags=["concert", "dance"],),
+                Event(name="Speech", tags=[],),
             ]
 
             STORE["events"] = events
@@ -105,6 +119,13 @@ def filter_events(**kwargs):
                             STORE["events"],
                         )
                     )
+                if "tags__exact" in kwargs:
+                    STORE["events"] = list(
+                        filter(
+                            lambda e: set(kwargs["tags__exact"]) == set(e.tags),
+                            STORE["events"],
+                        )
+                    )
 
             def mock_queryset_filter(*args, **kwargs):
                 filter_events(**kwargs)
@@ -121,7 +142,9 @@ def mock_queryset_count(*args, **kwargs):
             m_queryset.filter.side_effect = mock_queryset_filter
             m_queryset.none.side_effect = mock_queryset_none
             m_queryset.count.side_effect = mock_queryset_count
-            m_queryset.__getitem__.side_effect = STORE["events"].__getitem__
+            m_queryset.__getitem__.side_effect = lambda index: STORE[
+                "events"
+            ].__getitem__(index)
 
             return m_queryset
 

graphene_django/filter/tests/filters.py

@@ -10,7 +10,7 @@ class Meta:
         fields = {
             "headline": ["exact", "icontains"],
             "pub_date": ["gt", "lt", "exact"],
-            "reporter": ["exact"],
+            "reporter": ["exact", "in"],
         }
 
     order_by = OrderingFilter(fields=("pub_date",))

graphene_django/filter/tests/test_contains_filter.py → graphene_django/filter/tests/test_array_field_contains_filter.py

@@ -6,9 +6,9 @@
 
 
 @pytest.mark.skipif(ArrayField is MissingType, reason="ArrayField should exist")
-def test_string_contains_multiple(Query):
+def test_array_field_contains_multiple(Query):
     """
-    Test contains filter on a string field.
+    Test contains filter on a array field of string.
     """
 
     schema = Schema(query=Query)
@@ -32,9 +32,9 @@ def test_string_contains_multiple(Query):
 
 
 @pytest.mark.skipif(ArrayField is MissingType, reason="ArrayField should exist")
-def test_string_contains_one(Query):
+def test_array_field_contains_one(Query):
     """
-    Test contains filter on a string field.
+    Test contains filter on a array field of string.
     """
 
     schema = Schema(query=Query)
@@ -59,9 +59,9 @@ def test_string_contains_one(Query):
 
 
 @pytest.mark.skipif(ArrayField is MissingType, reason="ArrayField should exist")
-def test_string_contains_none(Query):
+def test_array_field_contains_empty_list(Query):
     """
-    Test contains filter on a string field.
+    Test contains filter on a array field of string.
     """
 
     schema = Schema(query=Query)
@@ -79,4 +79,9 @@ def test_string_contains_none(Query):
     """
     result = schema.execute(query)
     assert not result.errors
-    assert result.data["events"]["edges"] == []
+    assert result.data["events"]["edges"] == [
+        {"node": {"name": "Live Show"}},
+        {"node": {"name": "Musical"}},
+        {"node": {"name": "Ballet"}},
+        {"node": {"name": "Speech"}},
+    ]