graphene-django/docs/filtering.rst

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Filtering
=========
Graphene integrates with
`django-filter <https://django-filter.readthedocs.io/en/master/>`__ to provide filtering of results.
See the `usage documentation <https://django-filter.readthedocs.io/en/master/guide/usage.html#the-filter>`__
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for details on the format for ``filter_fields``.
This filtering is automatically available when implementing a ``relay.Node``.
Additionally ``django-filter`` is an optional dependency of Graphene.
You will need to install it manually, which can be done as follows:
.. code:: bash
# You'll need to install django-filter
pip install django-filter>=2
After installing ``django-filter`` you'll need to add the application in the ``settings.py`` file:
.. code:: python
INSTALLED_APPS = [
# ...
"django_filters",
]
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Note: The techniques below are demoed in the `cookbook example
app <https://github.com/graphql-python/graphene-django/tree/master/examples/cookbook>`__.
Filterable fields
-----------------
The ``filter_fields`` parameter is used to specify the fields which can
be filtered upon. The value specified here is passed directly to
``django-filter``, so see the `filtering
documentation <https://django-filter.readthedocs.io/en/master/guide/usage.html#the-filter>`__
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for full details on the range of options available.
For example:
.. code:: python
class AnimalNode(DjangoObjectType):
class Meta:
# Assume you have an Animal model defined with the following fields
model = Animal
fields = '__all__'
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filter_fields = ['name', 'genus', 'is_domesticated']
interfaces = (relay.Node, )
class Query(ObjectType):
animal = relay.Node.Field(AnimalNode)
all_animals = DjangoFilterConnectionField(AnimalNode)
You could then perform a query such as:
.. code::
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query {
# Note that fields names become camelcased
allAnimals(genus: "cat", isDomesticated: true) {
edges {
node {
id,
name
}
}
}
}
You can also make more complex lookup types available:
.. code:: python
class AnimalNode(DjangoObjectType):
class Meta:
model = Animal
fields = '__all__'
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# Provide more complex lookup types
filter_fields = {
'name': ['exact', 'icontains', 'istartswith'],
'genus': ['exact'],
'is_domesticated': ['exact'],
}
interfaces = (relay.Node, )
Which you could query as follows:
.. code::
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query {
# Note that fields names become camelcased
allAnimals(name_Icontains: "lion") {
edges {
node {
id,
name
}
}
}
}
Custom Filtersets
-----------------
By default Graphene provides easy access to the most commonly used
features of ``django-filter``. This is done by transparently creating a
``django_filters.FilterSet`` class for you and passing in the values for
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``filter_fields``.
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However, you may find this to be insufficient. In these cases you can
create your own ``FilterSet``. You can pass it directly as follows:
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.. code:: python
class AnimalNode(DjangoObjectType):
class Meta:
# Assume you have an Animal model defined with the following fields
model = Animal
fields = '__all__'
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filter_fields = ['name', 'genus', 'is_domesticated']
interfaces = (relay.Node, )
class AnimalFilter(django_filters.FilterSet):
# Do case-insensitive lookups on 'name'
name = django_filters.CharFilter(lookup_expr=['iexact'])
# Allow multiple genera to be selected at once
genera = django_filters.MultipleChoiceFilter(
field_name='genus',
choices=(
('Canis', 'Canis'),
('Panthera', 'Panthera'),
('Seahorse', 'Seahorse')
)
)
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class Meta:
model = Animal
fields = ['name', 'genus', 'is_domesticated']
class Query(ObjectType):
animal = relay.Node.Field(AnimalNode)
# We specify our custom AnimalFilter using the filterset_class param
all_animals = DjangoFilterConnectionField(AnimalNode,
filterset_class=AnimalFilter)
If you were interested in selecting all dogs and cats, you might query as follows:
.. code::
query {
allAnimals(genera: ["Canis", "Panthera"]) {
edges {
node {
id,
name
}
}
}
}
You can also specify the ``FilterSet`` class using the ``filterset_class``
parameter when defining your ``DjangoObjectType``, however, this can't be used
in unison with the ``filter_fields`` parameter:
.. code:: python
class AnimalFilter(django_filters.FilterSet):
# Do case-insensitive lookups on 'name'
name = django_filters.CharFilter(lookup_expr=['iexact'])
class Meta:
# Assume you have an Animal model defined with the following fields
model = Animal
fields = ['name', 'genus', 'is_domesticated']
class AnimalNode(DjangoObjectType):
class Meta:
model = Animal
fields = '__all__'
filterset_class = AnimalFilter
interfaces = (relay.Node, )
class Query(ObjectType):
animal = relay.Node.Field(AnimalNode)
all_animals = DjangoFilterConnectionField(AnimalNode)
The context argument is passed on as the `request argument <http://django-filter.readthedocs.io/en/master/guide/usage.html#request-based-filtering>`__
in a ``django_filters.FilterSet`` instance. You can use this to customize your
filters to be context-dependent. We could modify the ``AnimalFilter`` above to
pre-filter animals owned by the authenticated user (set in ``context.user``).
.. code:: python
class AnimalFilter(django_filters.FilterSet):
# Do case-insensitive lookups on 'name'
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name = django_filters.CharFilter(lookup_type=['iexact'])
class Meta:
model = Animal
fields = ['name', 'genus', 'is_domesticated']
@property
def qs(self):
# The query context can be found in self.request.
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return super(AnimalFilter, self).qs.filter(owner=self.request.user)
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Ordering
--------
You can use ``OrderFilter`` to define how you want your returned results to be ordered.
Extend the tuple of fields if you want to order by more than one field.
.. code:: python
from django_filters import FilterSet, OrderingFilter
class UserFilter(FilterSet):
class Meta:
model = UserModel
order_by = OrderingFilter(
fields=(
('name', 'created_at'),
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)
)
class Group(DjangoObjectType):
users = DjangoFilterConnectionField(Ticket, filterset_class=UserFilter)
class Meta:
name = 'Group'
model = GroupModel
fields = '__all__'
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interfaces = (relay.Node,)
def resolve_users(self, info, **kwargs):
return UserFilter(kwargs).qs
with this set up, you can now order the users under group:
.. code::
query {
group(id: "xxx") {
users(orderBy: "-created_at") {
xxx
}
}
}
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,)
fields = "__all__"
filterset_class = EventFilterSet
with this set up, you can now filter events by tags:
.. code::
query {
events(tags_Overlap: ["concert", "festival"]) {
name
}
}
`TypedFilter`
-------------
Sometimes the automatic detection of the filter input type is not satisfactory for what you are trying to achieve.
You can then explicitly specify the input type you want for your filter by using a `TypedFilter`:
.. code:: python
from django.db import models
from django_filters import FilterSet, OrderingFilter
import graphene
from graphene_django.filter import TypedFilter
class Event(models.Model):
name = models.CharField(max_length=50)
class EventFilterSet(FilterSet):
class Meta:
model = Event
fields = {
"name": ["exact", "contains"],
}
only_first = TypedFilter(input_type=graphene.Boolean, method="only_first_filter")
def only_first_filter(self, queryset, _name, value):
if value:
return queryset[:1]
else:
return queryset
class EventType(DjangoObjectType):
class Meta:
model = Event
interfaces = (Node,)
fields = "__all__"
filterset_class = EventFilterSet