RESTful API现在很流行,这里是它的介绍 理解RESTful架构和 RESTful API设计指南.按照Django的常规方法当然也可以实现REST,但有一种更快捷、强大的方法,那就是 Django REST framework.它是python的一个模块,通过在Django里面配置就可以把app的models中的各个表实现RESTful API。下面是实现方法:
一、安装配置
pip install djangorestframework pip install markdown # Markdown support for the browsable API. pip install django-filter # Filtering support
再到Django的 settings.py 中的INSTALLED_APPS
添加 rest_framework,如下:
INSTALLED_APPS = ( ... ‘rest_framework‘, )
在根目录的 url.py 文件中为rest_framework
框架的 login 和 logout 视图添加url:
urlpatterns = [ ... url(r‘^api-auth/‘, include(‘rest_framework.urls‘, namespace=‘rest_framework‘)) ]
二、创建model和Serializer
创建app,名为 snippets
.。在视图 models.py 中添加一张表如下:
from django.db import models from pygments.lexers import get_all_lexers # 一个实现代码高亮的模块 from pygments.styles import get_all_styles LEXERS = [item for item in get_all_lexers() if item[1]] LANGUAGE_CHOICES = sorted([(item[1][0], item[0]) for item in LEXERS]) # 得到所有编程语言的选项 STYLE_CHOICES = sorted((item, item) for item in get_all_styles()) # 列出所有配色风格 class Snippet(models.Model): created = models.DateTimeField(auto_now_add=True) title = models.CharField(max_length=100, blank=True, default=‘‘) code = models.TextField() linenos = models.BooleanField(default=False) language = models.CharField(choices=LANGUAGE_CHOICES, default=‘python‘, max_length=100) style = models.CharField(choices=STYLE_CHOICES, default=‘friendly‘, max_length=100) class Meta: ordering = (‘created‘,)
然后开始同步到数据库中:
./manage.py makemigrations snippets ./manage.py migrate
接下来需要做的就是创建 Serializer 类,类似于 Form。它的作用就是从你传入的参数中提取出你需要的数据,并把它转化为 json 格式(注意,已经是字节码了),同时支持反序列化到model对象。在 snippets 文件夹中添加
serializers.py
并在其添加如下:
from rest_framework import serializers
from snippets.models import Snippet, LANGUAGE_CHOICES, STYLE_CHOICES
class SnippetSerializer(serializers.Serializer): # 它序列化的方式很类似于Django的forms
id = serializers.IntegerField(read_only=True)
title = serializers.CharField(required=False, allow_blank=True, max_length=100)
code = serializers.CharField(style={‘base_template‘: ‘textarea.html‘}) # style的设置等同于Django的widget=widgets.Textarea
linenos = serializers.BooleanField(required=False) # 用于对浏览器的上的显示
language = serializers.ChoiceField(choices=LANGUAGE_CHOICES, default=‘python‘)
style = serializers.ChoiceField(choices=STYLE_CHOICES, default=‘friendly‘)
def create(self, validated_data):
"""
Create and return a new `Snippet` instance, given the validated data.
"""
return Snippet.objects.create(**validated_data)
def update(self, instance, validated_data):
"""
Update and return an existing `Snippet` instance, given the validated data.
"""
instance.title = validated_data.get(‘title‘, instance.title)
instance.code = validated_data.get(‘code‘, instance.code)
instance.linenos = validated_data.get(‘linenos‘, instance.linenos)
instance.language = validated_data.get(‘language‘, instance.language)
instance.style = validated_data.get(‘style‘, instance.style)
instance.save()
return instance
三、使用Serializer
先使用 ./manage.py shell 进入Django的shell中。操作如下:
可以看到 Serializer 的使用如同 Django 的 forms.它的反序列化如下:
from django.utils.six import BytesIO stream = BytesIO(content) data = JSONParser().parse(stream)
这是再把得到的数据转化为实例:
serializer = SnippetSerializer(data=data) serializer.is_valid() # 开始验证 # True serializer.validated_data # OrderedDict([(‘title‘, ‘‘), (‘code‘, ‘print "hello, world"\n‘), (‘linenos‘, False), (‘language‘, ‘python‘), (‘style‘, ‘friendly‘)]) serializer.save() # <Snippet: Snippet object>
同时,我们还可以对 querysets 进行序列化,只需简单地在设置参数 many=True,如下:
serializer = SnippetSerializer(Snippet.objects.all(), many=True) serializer.data # [OrderedDict([(‘id‘, 1), (‘title‘, u‘‘), (‘code‘, u‘foo = "bar"\n‘), (‘linenos‘, False), (‘language‘, ‘python‘), (‘style‘, ‘friendly‘)]), OrderedDict([(‘id‘, 2), (‘title‘, u‘‘), (‘code‘, u‘print "hello, world"\n‘), (‘linenos‘, False), (‘language‘, ‘python‘), (‘style‘, ‘friendly‘)]), OrderedDict([(‘id‘, 3), (‘title‘, u‘‘), (‘code‘, u‘print "hello, world"‘), (‘linenos‘, False), (‘language‘, ‘python‘), (‘style‘, ‘friendly‘)])
四、使用 ModelSerializer
ModelSerializer
类似于Django的 modelform, 可以直接关联到models中的表。如下:
class SnippetSerializer(serializers.ModelSerializer): class Meta: model = Snippet fields = (‘id‘, ‘title‘, ‘code‘, ‘linenos‘, ‘language‘, ‘style‘)
五、在Django的视图中使用Serializer
首先,可以像常规Django视图的写法一样写,返回序列化的输出数据。
from django.http import HttpResponse, JsonResponse from django.views.decorators.csrf import csrf_exempt from rest_framework.renderers import JSONRenderer from rest_framework.parsers import JSONParser from snippets.models import Snippet from snippets.serializers import SnippetSerializer @csrf_exempt def snippet_list(request): """ List all code snippets, or create a new snippet. """ if request.method == ‘GET‘: snippets = Snippet.objects.all() serializer = SnippetSerializer(snippets, many=True) return JsonResponse(serializer.data, safe=False) elif request.method == ‘POST‘: data = JSONParser().parse(request) serializer = SnippetSerializer(data=data) if serializer.is_valid(): serializer.save() return JsonResponse(serializer.data, status=201) return JsonResponse(serializer.errors, status=400)
也可以写一个视图对应其models中的表,实现对它的删、改、查。
@csrf_exempt def snippet_detail(request, pk): """ Retrieve, update or delete a code snippet. """ try: snippet = Snippet.objects.get(pk=pk) except Snippet.DoesNotExist: return HttpResponse(status=404) if request.method == ‘GET‘: serializer = SnippetSerializer(snippet) return JsonResponse(serializer.data) elif request.method == ‘PUT‘: data = JSONParser().parse(request) serializer = SnippetSerializer(snippet, data=data) if serializer.is_valid(): serializer.save() return JsonResponse(serializer.data) return JsonResponse(serializer.errors, status=400) elif request.method == ‘DELETE‘: snippet.delete() return HttpResponse(status=204)
添加对应的url, snippets/urls.py 中设置如下:
from django.conf.urls import url from snippets import views urlpatterns = [ url(r‘^snippets/$‘, views.snippet_list), url(r‘^snippets/(?P<pk>[0-9]+)/$‘, views.snippet_detail), ]
最后还要在根目录的 url.py 中添加对应的映射。
urlpatterns = [ ... url(r‘^‘, include(‘snippets.urls‘)), ]
这时,所有的配置已经完成了。接下来就是测试我们的API
六、测试API
为了方便我们可以使用 httpie 模块来测试,启动Django,再在客户端输入
http://127.0.0.1:8000/snippets/,操作如下:
如此简单。。。。。。。