Adding support for filtering by global ID

This is supported for AutoFields, OneToOneFields, and ForeignKey.
I have also added the GrapheneFilterSet base class. This provides
customsiations needed for Graphene. However, making developers
tie their FilterSets to Graphene would not be ideal as it would
prevent their use elsewhere. I therefore wrap any FilterSets
provided to Graphene with this additional functionality.

See `setup_filterset()` for how this is done. Such FilterSets
are also created by `custom_filterset_factory()` (in times
when a filterset is implicitly required via the `fields`
or `order_by` params passed to `DjangoFilterConnectionField`.

graphene/contrib/django/converter.py

@@ -1,4 +1,3 @@
-from django import forms
 from django.db import models
 from singledispatch import singledispatch
 

graphene/contrib/django/fields.py

@@ -1,8 +1,8 @@
 import warnings
 
 import six
-from django_filters import FilterSet
 
+from graphene.contrib.django.filterset import setup_filterset
 from ...core.exceptions import SkipField
 from ...core.fields import Field
 from ...core.types import Argument, String
@@ -13,6 +13,7 @@ from ...relay.utils import is_node
 from .form_converter import convert_form_field
 from .resolvers import FilterConnectionResolver
 from .utils import get_type_for_model
+from .filterset import custom_filterset_factory
 
 
 class DjangoConnectionField(ConnectionField):
@@ -66,23 +67,11 @@ class DjangoModelField(FieldType):
         return get_type_for_model(schema, self.model)
 
 
-def custom_filterset_factory(model, filter_base_class=FilterSet, **meta):
-    meta.update({
-        'model': model,
-    })
-    meta_class = type(str('Meta'), (object,), meta)
-    filterset = type(str('%sFilterSet' % model._meta.object_name),
-                     (filter_base_class,), {'Meta': meta_class})
-    return filterset
-
-
 class DjangoFilterConnectionField(DjangoConnectionField):
 
     def __init__(self, type, filterset_class=None, resolver=None, on=None,
                  fields=None, order_by=None, extra_filter_meta=None,
                  *args, **kwargs):
-        if not resolver:
-            resolver = FilterConnectionResolver(type, on, filterset_class)
 
         if not filterset_class:
             # If no filter class is specified then create one given the
@@ -95,6 +84,11 @@ class DjangoFilterConnectionField(DjangoConnectionField):
             if extra_filter_meta:
                 meta.update(extra_filter_meta)
             filterset_class = custom_filterset_factory(**meta)
+        else:
+            filterset_class = setup_filterset(filterset_class)
+
+        if not resolver:
+            resolver = FilterConnectionResolver(type, on, filterset_class)
 
         kwargs.setdefault('args', {})
         kwargs['args'].update(**self.get_filtering_args(type, filterset_class))

graphene/contrib/django/filterset.py

@@ -0,0 +1,71 @@
+import six
+from django.db import models
+from django_filters import Filter
+from django_filters.filterset import FilterSetMetaclass, FilterSet
+from graphql_relay.node.node import from_global_id
+
+from graphene.contrib.django.forms import GlobalIDFormField
+
+
+class GlobalIDFilter(Filter):
+    field_class = GlobalIDFormField
+
+    def filter(self, qs, value):
+        gid = from_global_id(value)
+        return super(GlobalIDFilter, self).filter(qs, gid.id)
+
+
+GRAPHENE_FILTER_SET_OVERRIDES = {
+    models.AutoField: {
+        'filter_class': GlobalIDFilter,
+    },
+    models.OneToOneField: {
+        'filter_class': GlobalIDFilter,
+    },
+    models.ForeignKey: {
+        'filter_class': GlobalIDFilter,
+    }
+    # TODO: Support ManyToManyFields. GlobalIDFilterList?
+}
+
+
+class GrapheneFilterSetMetaclass(FilterSetMetaclass):
+    def __new__(cls, name, bases, attrs):
+        new_class = super(GrapheneFilterSetMetaclass, cls).__new__(cls, name, bases, attrs)
+        # Customise the filter_overrides for Graphene
+        for k, v in GRAPHENE_FILTER_SET_OVERRIDES.items():
+            new_class.filter_overrides.setdefault(k, v)
+        return new_class
+
+
+class GrapheneFilterSet(six.with_metaclass(GrapheneFilterSetMetaclass, FilterSet)):
+    """ Base class for FilterSets used by Graphene
+
+    You shouldn't usually need to use this class. The
+    DjangoFilterConnectionField will wrap FilterSets with this class as
+    necessary
+    """
+    pass
+
+
+def setup_filterset(filterset_class):
+    """ Wrap a provided filterset in Graphene-specific functionality
+    """
+    return type(
+        'Graphene{}'.format(filterset_class.__name__),
+        (six.with_metaclass(GrapheneFilterSetMetaclass, filterset_class),),
+        {},
+    )
+
+
+def custom_filterset_factory(model, filterset_base_class=GrapheneFilterSet,
+                             **meta):
+    """ Create a filterset for the given model using the provided meta data
+    """
+    meta.update({
+        'model': model,
+    })
+    meta_class = type(str('Meta'), (object,), meta)
+    filterset = type(str('%sFilterSet' % model._meta.object_name),
+                     (filterset_base_class,), {'Meta': meta_class})
+    return filterset

graphene/contrib/django/form_converter.py

@@ -10,6 +10,7 @@ except AttributeError:
     class UUIDField(object):
         pass
 
+
 @singledispatch
 def convert_form_field(field):
     raise Exception(

graphene/contrib/django/forms.py

@@ -0,0 +1,30 @@
+import binascii
+
+from django.core.exceptions import ValidationError
+from django.forms import Field, IntegerField, CharField
+from django.utils.translation import ugettext_lazy as _
+
+from graphql_relay import from_global_id
+
+
+class GlobalIDFormField(Field):
+    default_error_messages = {
+        'invalid': _('Invalid ID specified.'),
+    }
+
+    def clean(self, value):
+        if not value and not self.required:
+            return None
+
+        try:
+            gid = from_global_id(value)
+        except (UnicodeDecodeError, TypeError, binascii.Error):
+            raise ValidationError(self.error_messages['invalid'])
+
+        try:
+            IntegerField().clean(gid.id)
+            CharField().clean(gid.type)
+        except ValidationError:
+            raise ValidationError(self.error_messages['invalid'])
+
+        return value

graphene/contrib/django/tests/test_fields.py

@@ -1,4 +1,8 @@
+import django_filters
+
 from graphene.contrib.django import DjangoFilterConnectionField, DjangoNode
+from graphene.contrib.django.filterset import GlobalIDFilter
+from graphene.contrib.django.forms import GlobalIDFormField
 from graphene.contrib.django.tests.filters import ArticleFilter, PetFilter
 from graphene.contrib.django.tests.models import Article, Pet
 
@@ -56,9 +60,9 @@ def test_filter_shortcut_filterset_arguments_list():
 
 def test_filter_shortcut_filterset_arguments_dict():
     field = DjangoFilterConnectionField(ArticleNode, fields={
-            'headline': ['exact', 'icontains'],
-            'reporter': ['exact'],
-        })
+        'headline': ['exact', 'icontains'],
+        'reporter': ['exact'],
+    })
     assert_arguments(field,
                      'headline', 'headlineIcontains',
                      'reporter',
@@ -90,3 +94,32 @@ def test_filter_shortcut_filterset_extra_meta():
         'ordering': True
     })
     assert_orderable(field)
+
+
+def test_global_id_field_implicit():
+    field = DjangoFilterConnectionField(ArticleNode, fields=['id'])
+    filterset_class = field.resolver_fn.filterset_class
+    id_filter = filterset_class.base_filters['id']
+    assert isinstance(id_filter, GlobalIDFilter)
+    assert id_filter.field_class == GlobalIDFormField
+
+
+def test_global_id_field_explicit():
+    class ArticleIdFilter(django_filters.FilterSet):
+        class Meta:
+            model = Article
+            fields = ['id']
+
+    field = DjangoFilterConnectionField(ArticleNode, filterset_class=ArticleIdFilter)
+    filterset_class = field.resolver_fn.filterset_class
+    id_filter = filterset_class.base_filters['id']
+    assert isinstance(id_filter, GlobalIDFilter)
+    assert id_filter.field_class == GlobalIDFormField
+
+
+def test_global_id_field_relation():
+    field = DjangoFilterConnectionField(ArticleNode, fields=['reporter'])
+    filterset_class = field.resolver_fn.filterset_class
+    id_filter = filterset_class.base_filters['reporter']
+    assert isinstance(id_filter, GlobalIDFilter)
+    assert id_filter.field_class == GlobalIDFormField

graphene/contrib/django/tests/test_forms.py

@@ -0,0 +1,36 @@
+from django.core.exceptions import ValidationError
+from py.test import raises
+
+from graphene.contrib.django.forms import GlobalIDFormField
+
+
+# 'TXlUeXBlOjEwMA==' -> 'MyType', 100
+# 'TXlUeXBlOmFiYw==' -> 'MyType', 'abc'
+
+
+def test_global_id_valid():
+    field = GlobalIDFormField()
+    field.clean('TXlUeXBlOjEwMA==')
+
+
+def test_global_id_invalid():
+    field = GlobalIDFormField()
+    with raises(ValidationError):
+        field.clean('badvalue')
+
+
+def test_global_id_none():
+    field = GlobalIDFormField()
+    with raises(ValidationError):
+        field.clean(None)
+
+
+def test_global_id_none_optional():
+    field = GlobalIDFormField(required=False)
+    field.clean(None)
+
+
+def test_global_id_bad_int():
+    field = GlobalIDFormField()
+    with raises(ValidationError):
+        field.clean('TXlUeXBlOmFiYw==')