Quickstart
We’re going to create a simple API to allow admin users to view and edit the users and groups in the system.
Project setup
Create a new Django project named tutorial , then start a new app called quickstart .
# Create the project directory mkdir tutorial cd tutorial # Create a virtual environment to isolate our package dependencies locally python3 -m venv env source env/bin/activate # On Windows use `env\Scripts\activate` # Install Django and Django REST framework into the virtual environment pip install django pip install djangorestframework # Set up a new project with a single application django-admin startproject tutorial . # Note the trailing '.' character cd tutorial django-admin startapp quickstart cd .. The project layout should look like:
$ pwd /tutorial $ find . . ./manage.py ./tutorial ./tutorial/__init__.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/asgi.py ./tutorial/settings.py ./tutorial/urls.py ./tutorial/wsgi.py It may look unusual that the application has been created within the project directory. Using the project’s namespace avoids name clashes with external modules (a topic that goes outside the scope of the quickstart).
Now sync your database for the first time:
We’ll also create an initial user named admin with a password of password123 . We’ll authenticate as that user later in our example.
python manage.py createsuperuser --email admin@example.com --username admin Once you’ve set up a database and the initial user is created and ready to go, open up the app’s directory and we’ll get coding.
Serializers
First up we’re going to define some serializers. Let’s create a new module named tutorial/quickstart/serializers.py that we’ll use for our data representations.
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'] Notice that we’re using hyperlinked relations in this case with HyperlinkedModelSerializer . You can also use primary key and various other relationships, but hyperlinking is good RESTful design.
Views
Right, we’d better write some views then. Open tutorial/quickstart/views.py and get typing.
from django.contrib.auth.models import User, Group from rest_framework import viewsets from rest_framework import permissions 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 permission_classes = [permissions.IsAuthenticated] class GroupViewSet(viewsets.ModelViewSet): """ API endpoint that allows groups to be viewed or edited. """ queryset = Group.objects.all() serializer_class = GroupSerializer permission_classes = [permissions.IsAuthenticated] Rather than write multiple views we’re grouping together all the common behavior into classes called ViewSets .
We can easily break these down into individual views if we need to, but using viewsets keeps the view logic nicely organized as well as being very concise.
URLs
Okay, now let’s wire up the API URLs. On to tutorial/urls.py .
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')) ] Because we’re using viewsets instead of views, we can automatically generate the URL conf for our API, by simply registering the viewsets with a router class.
Again, if we need more control over the API URLs we can simply drop down to using regular class-based views, and writing the URL conf explicitly.
Finally, we’re including default login and logout views for use with the browsable API. That’s optional, but useful if your API requires authentication and you want to use the browsable API.
Pagination
Pagination allows you to control how many objects per page are returned. To enable it add the following lines to tutorial/settings.py
Settings
Add ‘rest_framework’ to INSTALLED_APPS . The settings module will be in tutorial/settings.py
INSTALLED_APPS = [ . 'rest_framework', ] Testing our API
We’re now ready to test the API we’ve built. Let’s fire up the server from the command line.
python manage.py runserver We can now access our API, both from the command-line, using tools like curl .
bash: curl -H 'Accept: application/json; indent=4' -u admin:password123 http://127.0.0.1:8000/users/ < "count": 2, "next": null, "previous": null, "results": [ < "email": "admin@example.com", "groups": [], "url": "http://127.0.0.1:8000/users/1/", "username": "admin" >, ] > Or using the httpie, command line tool.
bash: http -a admin:password123 http://127.0.0.1:8000/users/ HTTP/1.1 200 OK . < "count": 2, "next": null, "previous": null, "results": [ < "email": "admin@example.com", "groups": [], "url": "http://localhost:8000/users/1/", "username": "paul" >, ] > Or directly through the browser, by going to the URL http://127.0.0.1:8000/users/ .
If you’re working through the browser, make sure to login using the control in the top right corner.
If you want to get a more in depth understanding of how REST framework fits together head on over to the tutorial, or start browsing the API guide.
Web API с помощью Django REST framework
Веб-cервис (англ. web service) — идентифицируемая веб-адресом программная система со стандартизированными интерфейсами. Веб-службы могут взаимодействовать друг с другом и со сторонними приложениями посредством сообщений, основанных на определённых протоколах (XML, JSON и т. д.). Веб-служба является единицей модульности при использовании сервис-ориентированной архитектуры приложения.
Одним из подходов создания веб сервиса является rest.
Rest (сокр. англ. Representational State Transfer, «передача состояния представления») — стиль построения архитектуры распределенного приложения. Данные в REST должны передаваться в виде небольшого количества стандартных форматов (например HTML, XML, JSON). Сетевой протокол (как и HTTP) должен поддерживать кэширование, не должен зависеть от сетевого слоя, не должен сохранять информацию о состоянии между парами «запрос-ответ». Утверждается, что такой подход обеспечивает масштабируемость системы и позволяет ей эволюционировать с новыми требованиями.
Django REST framework — удобный инструмент для работы с rest основанный на идеологии фреймворка Django.
Требования к окружению:
Python (2.6, 2.7)
Django (1.3, 1.4, 1.5)
Установка
pip install djangorestframework pip install markdown pip install pyyaml pip install django-filter Или же сделать клон проекта с Github:
git clone git@github.com:tomchristie/django-rest-framework.git cd django-rest-framework pip install -r requirements.txt pip install -r optionals.txt Не забываем прописать приложение в INSTALLED_APPS:
INSTALLED_APPS = ( . 'rest_framework', ) А также добавить запись в urls.py:
urlpatterns = patterns('', . url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework')) ) Url можно ставить любой на Ваш вкус, главное подключить файл с урлами rest framework (rest_framework.urls).
Пример использования
Создадим API для работы с пользователями и их группами.
Для начала нам нужно определить некоторые Serializers, которые мы будем использовать
from django.contrib.auth.models import User, Group, Permission from rest_framework import serializers class UserSerializer(serializers.HyperlinkedModelSerializer): class Meta: model = User fields = ('url', 'username', 'email', 'groups') class GroupSerializer(serializers.HyperlinkedModelSerializer): permissions = serializers.ManySlugRelatedField( slug_field='codename', queryset=Permission.objects.all() ) class Meta: model = Group fields = ('url', 'name', 'permissions') Пропишем views.py
from django.contrib.auth.models import User, Group from rest_framework import generics from rest_framework.decorators import api_view from rest_framework.reverse import reverse from rest_framework.response import Response from quickstart.serializers import UserSerializer, GroupSerializer @api_view(['GET']) def api_root(request, format=None): """ The entry endpoint of our API. """ return Response(< 'users': reverse('user-list', request=request), 'groups': reverse('group-list', request=request), >) class UserList(generics.ListCreateAPIView): """ API endpoint that represents a list of users. """ model = User serializer_class = UserSerializer class UserDetail(generics.RetrieveUpdateDestroyAPIView): """ API endpoint that represents a single user. """ model = User serializer_class = UserSerializer class GroupList(generics.ListCreateAPIView): """ API endpoint that represents a list of groups. """ model = Group serializer_class = GroupSerializer class GroupDetail(generics.RetrieveUpdateDestroyAPIView): """ API endpoint that represents a single group. """ model = Group serializer_class = GroupSerializer Мы создали функцию api_root, которая будет отправной точкой для нашего API. И четыре класса, для связи с моделями и указали какие serializers нужно при этом использовать.
Добавим ссылки в urls.py
from django.conf.urls import patterns, url, include from rest_framework.urlpatterns import format_suffix_patterns from quickstart.views import UserList, UserDetail, GroupList, GroupDetail urlpatterns = patterns('quickstart.views', url(r'^$', 'api_root'), url(r'^users/$', UserList.as_view(), name='user-list'), url(r'^users/(?P\d+)/$', UserDetail.as_view(), name='user-detail'), url(r'^groups/$', GroupList.as_view(), name='group-list'), url(r'^groups/(?P\d+)/$', GroupDetail.as_view(), name='group-detail'), ) # Format suffixes urlpatterns = format_suffix_patterns(urlpatterns, allowed=['json', 'api']) # Default login/logout views urlpatterns += patterns('', url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework')) ) Важный момент использование user-detail и group-detail. Для корректной связи с views.py нужно использовать именование вида -detail.
В format_suffix_patterns мы указали суфикс для наших urls.
Settings
INSTALLED_APPS = ( . 'rest_framework', ) REST_FRAMEWORK =
Результат
bash: curl -H 'Accept: application/json; indent=4' -u admin:password http://127.0.0.1:8000/users/ < "count": 2, "next": null, "previous": null, "results": [ < "email": "admin@example.com", "groups": [], "url": "http://127.0.0.1:8000/users/1/", "username": "admin" >, < "email": "tom@example.com", "groups": [ ], "url": "http://127.0.0.1:8000/users/2/", "username": "tom" >] > 
В браузере можно увидить что то подобное:
P.S. Для работы с rest в django есть еще одно не плохое приложение именуемое как django-piston. При желании можно и о нем написать, хотя в использовании оно довольно не сложное.