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Description:

djangorestwitchcraft 0.12.1

Django REST Witchcraft

Django REST Framework integration with SQLAlchemy
django-rest-witchcraft is an extension for Django REST Framework that adds support for SQLAlchemy. It aims to provide
a similar development experience to building REST api’s with Django REST Framework with Django ORM, except with
SQLAlchemy.

Installation
pip install django-rest-witchcraft

Quick Start
First up, lets define some simple models:
import sqlalchemy as sa
import sqlalchemy.orm # noqa
from sqlalchemy.ext.declarative import declarative_base

engine = sa.create_engine('sqlite:///:memory:', echo=True)
session = sa.orm.scoped_session(sa.orm.sessionmaker(bind=engine))

Base = declarative_base()
Base.query = session.query_property()

class Group(Base):
__tablename__ = 'groups'

id = sa.Column(sa.Integer(), primary_key=True, autoincrement=True)
name = sa.Column(sa.String())

class User(Base):
__tablename__ = 'users'

id = sa.Column(sa.Integer(), primary_key=True, autoincrement=True)
name = sa.Column(sa.String())
fullname = sa.Column(sa.String())
password = sa.Column(sa.String())

_group_id = sa.Column('group_id', sa.Integer(), sa.ForeignKey('groups.id'))
group = sa.orm.relationship(Group, backref='users')

class Address(Base):
__tablename__ = 'addresses'

id = sa.Column(sa.Integer(), primary_key=True, autoincrement=True)
email_address = sa.Column(sa.String(), nullable=False)

_user_id = sa.Column(sa.Integer(), sa.ForeignKey('users.id'))
user = sa.orm.relationship(User, backref='addresses')

Base.metadata.create_all(engine)
Nothing fancy here, we have a User class that can belongs to a Group instance and has many Address
instances
This serializer can handle nested create, update or partial update operations.
Lets define a serializer for User with all the fields:
class UserSerializer(serializers.ModelSerializer):

class Meta:
model = User
session = session
fields = '__all__'
This will create the following serializer for us:
>>> serializer = UserSerializer()

>>> serializer
UserSerializer():
id = IntegerField(allow_null=False, help_text=None, label='Id', required=True)
name = CharField(allow_null=True, help_text=None, label='Name', max_length=None, required=False)
fullname = CharField(allow_null=True, help_text=None, label='Fullname', max_length=None, required=False)
password = CharField(allow_null=True, help_text=None, label='Password', max_length=None, required=False)
group = GroupSerializer(allow_null=True, is_nested=True, required=False):
id = IntegerField(allow_null=False, help_text=None, label='Id', required=False)
name = CharField(allow_null=True, help_text=None, label='Name', max_length=None, required=False)
addresses = AddressSerializer(allow_null=True, many=True, required=False):
id = IntegerField(allow_null=False, help_text=None, label='Id', required=False)
email_address = CharField(allow_null=False, help_text=None, label='Email_address', max_length=None, required=True)
url = UriField(read_only=True)
Lets try to create a User instance with our brand new serializer:
serializer = UserSerializer(data={
'name': 'shosca',
'password': 'swordfish',
})
serializer.is_valid()
serializer.save()

user = serializer.instance
This will create the following user for us:
>>> user
User(_group_id=None, id=1, name='shosca', fullname=None, password='swordfish')
Lets try to update our user User instance and change its password:
serializer = UserSerializer(user, data={
'name': 'shosca',
'password': 'password',
})
serializer.is_valid()
serializer.save()

user = serializer.instance
Our user now looks like:
>>> user
User(_group_id=None, id=1, name='shosca', fullname=None, password='password')
Lets try to update our User instance again, but this time lets change its password only:
serializer = UserSerializer(user, data={
'password': 'swordfish',
}, partial=True)
serializer.is_valid()
serializer.save()

user = serializer.instance
This will update the following user for us:
>>> user
User(_group_id=None, id=1, name='shosca', fullname=None, password='swordfish')
Our user does not belong to a Group, lets fix that:
group = Group(name='Admin')
session.add(group)
session.flush()

serializer = UserSerializer(user, data={
'group': {'id': group.id}
})
serializer.is_valid()
serializer.save()

user = serializer.instance
Now, our user looks like:
>>> user
User(_group_id=1, id=1, name='shosca', fullname=None, password='swordfish')

>>> user.group
Group(id=1, name='Admin')
We can also change the name of our user’s group through the user using nested updates:
class UserSerializer(serializers.ModelSerializer):

class Meta:
model = User
session = session
fields = '__all__'
extra_kwargs = {
'group': {'allow_nested_updates': True}
}

serializer = UserSerializer(user, data={
'group': {'name': 'Super User'}
}, partial=True)
serializer.is_valid()

user = serializer.save()
Now, our user looks like:
>>> user
User(_group_id=1, id=1, name='shosca', fullname=None, password='swordfish')

>>> user.group
Group(id=1, name='Super User')
We can use this serializer in a viewset like:
from rest_witchcraft import viewsets

class UserViewSet(viewsets.ModelViewSet):
queryset = User.query
serializer_class = UserSerializer
And we can register this viewset in our urls.py like:
from rest_witchcraft import routers

router = routers.DefaultRouter()
router.register(r'users', UserViewSet)

urlpatterns = [
...
url(r'^', include(router.urls)),
...
]