Django REST frameworkチュートリアル

公式のQuick Startからチュートリアルへ。

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$ mkdir tutorial
$ cd tutorial
$ django-admin startproject tutorial .
$ cd tutorial
$ django-admin startapp quickstart
$ pwd
/work/tutorial/tutorial
$ cd ..
$ find .
.
./manage.py
./tutorial
./tutorial/__init__.py
./tutorial/asgi.py
./tutorial/quickstart
./tutorial/quickstart/__init__.py
./tutorial/quickstart/admin.py
./tutorial/quickstart/apps.py
./tutorial/quickstart/migrations
./tutorial/quickstart/migrations/__init__.py
./tutorial/quickstart/models.py
./tutorial/quickstart/tests.py
./tutorial/quickstart/views.py
./tutorial/settings.py
./tutorial/urls.py
./tutorial/wsgi.py
$ ./manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, sessions
Running migrations:
  Applying contenttypes.0001_initial... OK
  Applying auth.0001_initial... OK
  Applying admin.0001_initial... OK
  Applying admin.0002_logentry_remove_auto_add... OK
  Applying admin.0003_logentry_add_action_flag_choices... OK
  Applying contenttypes.0002_remove_content_type_name... OK
  Applying auth.0002_alter_permission_name_max_length... OK
  Applying auth.0003_alter_user_email_max_length... OK
  Applying auth.0004_alter_user_username_opts... OK
  Applying auth.0005_alter_user_last_login_null... OK
  Applying auth.0006_require_contenttypes_0002... OK
  Applying auth.0007_alter_validators_add_error_messages... OK
  Applying auth.0008_alter_user_username_max_length... OK
  Applying auth.0009_alter_user_last_name_max_length... OK
  Applying auth.0010_alter_group_name_max_length... OK
  Applying auth.0011_update_proxy_permissions... OK
  Applying sessions.0001_initial... OK
$ ./manage.py createsuperuser --email admin@example.com --username admin
Password: ********
Password (again): ********
Superuser created successfully.

Serializers

Serializer（tutorial/quickstart/serializers.py）を定義。
SerializerはデータをPythonデータ型に変換し、JSONなどのコンテンツタイプにレンダリングする処理を担う。
既定のクラスを継承して実装する。ここでは主キーフィールドの変わりにurlフィールドを使用するHyperlinkedModelSerializerを使用している。

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from django.contrib.auth.models import User, Group
from rest_framework import serializers


class UserSerializer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = User
        fields = ['url', 'username', 'email', 'groups']


class GroupSerializer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = Group
        fields = ['url', 'name']

Views

View（tutorial/quickstart/views.py）を定義。
ViewSetsでモデルのCRUD操作を暗黙的に実装している。

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from django.contrib.auth.models import User, Group
from rest_framework import viewsets
from tutorial.quickstart.serializers import UserSerializer, GroupSerializer


class UserViewSet(viewsets.ModelViewSet):
    """
    API endpoint that allows users to be viewed or edited.
    """
    queryset = User.objects.all().order_by('-date_joined')
    serializer_class = UserSerializer


class GroupViewSet(viewsets.ModelViewSet):
    """
    API endpoint that allows groups to be viewed or edited.
    """
    queryset = Group.objects.all()
    serializer_class = GroupSerializer

URLs

url（tutorial/urls.py）を定義。

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from django.urls import include, path
from rest_framework import routers
from tutorial.quickstart import views

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

# Wire up our API using automatic URL routing.
# Additionally, we include login URLs for the browsable API.
urlpatterns = [
    path('', include(router.urls)),
    path('api-auth/', include('rest_framework.urls', namespace='rest_framework'))
]

Pagination

settings（tutorial/settings.py）をカスタマイズ。

  • SECRET_KEYを環境変数で定義する
  • INSTALL_APPSでrest_frameworkを追加する
  • Pagenation（次のページ）を有効化する
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# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = os.environ['SECRET_KEY']

…略…

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'rest_framework',
]

REST_FRAMEWORK = {
    'DEFAULT_PAGINATION_CLASS': 'rest_framework.pagination.PageNumberPagination',
    'PAGE_SIZE': 10
}

アクセス

Viewとしてusersとgroupsが定義されている

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$ curl -H 'Accept: application/json; indent=4' -u admin:adminadmin http://127.0.0.1:8000/
{
    "users": "http://127.0.0.1:8000/users/",
    "groups": "http://127.0.0.1:8000/groups/"
}

Django REST framework quickstart width=640

Paginationを設定したので、応答にnextとpreviousが追加されている。アイテム数が少ないので、値はnull。

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$ curl -H 'Accept: application/json; indent=4' -u admin:adminadmin http://127.0.0.1:8000/users/
{
    "count": 1,
    "next": null,
    "previous": null,
    "results": [
        {
            "url": "http://127.0.0.1:8000/users/1/",
            "username": "admin",
            "email": "admin@example.com",
            "groups": []
        }
    ]
}
$ curl -H 'Accept: application/json; indent=4' -u admin:adminadmin http://127.0.0.1:8000/groups/
{
    "count": 0,
    "next": null,
    "previous": null,
    "results": []
}

Django REST framework quickstart width=640

Django REST framework quickstart width=640