RESTful API : 面向资源编程

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pip install djangorestframework
pip install markdown       # Markdown support for the browsable API.
pip install django-filter  # Filtering support look docs

快速使用

# step 1：注册 App -> setting.py
INSTALLED_APPS = [
    ...
    'rest_framework', # <---
]
# step 2：注册路由 api--->urls.py(单独App)
from rest_framework import routers
from . import views

router = routers.DefaultRouter()
router.register('users',Views.UserInfoViewSet)

urlpatterns = [
    # 登录功能
    url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework'))
    url(r'^'),include(router.urls)),
]

# step 3：view.py
from app01.models import *
from rest_framework.viewsets import ModelViewSet
from rest_framework.serializers import HyperlinkedModelSerializer

# Create your views here.

class UsersSerializer(HyperlinkedModelSerializer):
    ''' rest api 数据定制 指定显示的数据 '''
    class Meta:
        model = User
        fields = ('id','username')  # 字段
        # exclude = ('password',)    # 除这个字段以外
        depth = 0                   # 0 <= depth <= 10   查询外键 0 只查自己的表 1 关联的下一层也会拿到 ...

class UsersViewSet(ModelViewSet):
    queryset = User.objects.all().order_by('-id')
    serializer_class = UsersSerializer    # 验证数据库操作 相当于 Form的功能

CBV

urls.py

urlpatterns = [
    url(r'user/$', views.UserView.as_view()),  # CBV
    # url(r'user/(?P<pk>[0-9]+)/$',views.UserDetail.as_view()), # CBV
    url(r'user/(\d+)/$', views.UserDetail.as_view()),  # CBV
]

view.py

from rest_framework.views import APIView
from app01 import serializers
from rest_framework.parsers import JSONParser   # json -> loads

class UserView(APIView):
    def get(self, request, *args, **kwargs):
        """ 获取多条数据 """
        data_list = User.objects.all()

        # 1. django 序列化
        # from django.core import serializers
        # data = serializers.serialize('json',data_list)
        # return HttpResponse(data)

        # 2. rest framework 序列化 + form 验证 + 自定义
        serializer = serializers.MySerializer(instance=data_list, many=True)  # many -> 单条 or 多条
        # return HttpResponse(json.dumps(serializer.data,ensure_ascii=False))   # 正常显示中文
        return JsonResponse(serializer.data,safe=False,json_dumps_params={"ensure_ascii":False})

    def post(self, request, *args, **kwargs):
        """ 创建数据 """
        # old
        # print(request.data)
        # Blog.objects.create(**request.data)
        # rest framework
        data = JSONParser().parse(request)
        serializer = serializers.MySerializer(data=data)
        if serializer.is_valid():
            # print(serializer.data)
            # print(serializer.errors)
            # print(serializer.validated_data)
            # 如果有 instance，则执行 update 方法；否则执行 create
            serializer.save()
        return HttpResponse('...')


class UserDetail(APIView):
    def get(self, request, nid):  # *args,**kwargs ->  pk`
        """ 获取单条数据 """
        obj = User.objects.filter(nid=nid).first()
        serializer = serializers.MySerializer(instance=obj)
        return JsonResponse(serializer.data, safe=False, json_dumps_params={"ensure_ascii": False})

    def put(self, request, nid):  # *args,**kwargs ->  pk`
        ''' 修改单条数据 '''
        obj = User.objects.filter(nid=nid).first()
        data = JSONParser().parse(request)
        serializer = serializers.MySerializer(instance=obj,data=data)
        if serializer.is_valid():
            serializer.save()
            return HttpResponse(200)
        # TODO

    def delete(self, request, nid):  # *args,**kwargs ->  pk`
        """ 删除数据 """
        obj = User.objects.filter(nid=nid).delete()
        return HttpResponse(status=204)

new file serializers.py

from rest_framework import serializers
from app01 import models


class MySerializer(serializers.Serializer):
    nid = serializers.IntegerField(read_only=True)
    username = serializers.CharField(max_length=64)
    password = serializers.CharField(max_length=32)
    email = serializers.CharField(max_length=32)

    # 和 Form 表单一样
    def validate_username(self, value):
        return value

    def validate_email(self, value):
        return value

    def update(self, instance, validated_data):
        instance.name = validated_data['name']
        instance.user = validated_data['user']
        instance.save()

    def create(self, validated_data):
        models.User.objects.create(**validated_data)

总结

2 个 url
5 个方法

最多进行跨表查询，综合数据展示出来
参考

DRF doc

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from rest_framework.documentation import include_docs_urls
# urls.py
url(r'docs/', include_docs_urls(title="example title"))

Django View

使用Django序列化数据

from django.views.generic.base import View, ListView, DateDetailView, DeleteView, DatailView, TemplateView
# django 序列化
from django.forms.models import model_to_dict
from dhango.core.serializers import serialize
json_data = serialize('json', <query>)
from django.http import JsonResponse

DRF view

Serializer

数据序列化，如果需要序列化外键的数据就再创建一个Serializer.

from rest_framework import serializers
from snippets.models import Snippet, LANGUAGE_CHOICES, STYLE_CHOICES


class SnippetSerializer(serializers.Serializer):
    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'})
    linenos = serializers.BooleanField(required=False)
    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

ModelSerializer

这个可以把所有的字段给省略掉，create,update也可以省掉

APIView

数据列表，继承自View

Using mixins | generics

使用mixins，generics更高级的封装来更容易的写接口，继承generics这个文件里面的方法，可以只使用其中某一个功能，但是generics这个不论什么组合都不能少

mixins : 数据的操作
generics : http的操作
drf 就是这些的组合

自定义页码

from rest_framework.pagination import PageNumberPagination

class ExamplePagination(PageNumberPagination):
    page_size = 10
    page_size_query_param = 'page_size'
    page_query_param = 'p'
    max_page_size = 100

viewsets

各种组合 mixins, GenericViewSet
这个是推荐，常用的，仅限于 view class，它是通过路由绑定。更高级的封装

viewsets.GenericViewSet

class Example(mixins.ListModelMinxin, viewsets.GenericViewSet)
    '''GenericViewSet 没有继承 get post 方法，所以还是需要 mixins'''
    pass
# 在 urls 里面来绑定函数 action
# https://www.django-rest-framework.org/tutorial/6-viewsets-and-routers/#binding-viewsets-to-urls-explicitly

分析 view

generics 里有各种组合view,

GenericViewSet(viewset) # drf
GenericAPIView          # drf
APIView                 # drf
View                    # django
# 越往后的 View 越底层

mixin

CreateModelMixin
ListModelMixin
UpdateModelMixin
RetrieveModelMixin
DestoryModelMixin

req | rep

DRF 中的requests,response

Filter

1	pip install django-filter

Django Filter

django filter docs

import django_filters
from app import model_name

class ExampleFilter(django_filters.rest_framework.FilterSet):
    # 大于和小于
    price_min = django_filters.NumberFilter(name='price', lookup_expr='gt') 
    price_max = django_filters.NumberFilter(name='price', lookup_expr='lt')
    name = django_fileter.CharFilter(name='name', lookup_expr='icontains')
    class Meta:
        model = model_name
        fields = ['price_min', 'price_max', 'name']


class ModelNameListViewSet(...):
    ...
    filter_class = ExampleFilter

DRF Filter

from rest_framework import filters

ExampleDRFilter(...):
    ...
    filter_backends = (..., filters.SearchFilter)
    # 下面的可以加正则
    search_fields = ('username', 'eamil',)
    ordering_field = ('age', 'add_time')

HTTP

1 2	# 状态 from rest_framework import status

Django rest framwork 快速使用