django的rest framework框架——分页、视图、路由、渲染器

一、rest framework的分页

1、使用rest framework内置类PageNumberPagination实现分类

from django.conf.urls import url
from api import views

urlpatterns = [
    url(r'^(?P<version>[v1|v2]+)/pager1/$', views.Pager1View.as_view()),
]

from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.pagination import PageNumberPagination

from api import models
from api.utils.serializers.pager import PagerSerializer


class Pager1View(APIView):
    """分页"""
    def get(self, request, *args, **kwargs):
        roles = models.Role.objects.all()
        # 使用PageNumberPagination类进行分页
        pg = PageNumberPagination()
        # 获取分页数据
        pager_roles = pg.paginate_queryset(queryset=roles, request=request, view=self)
        # 序列化分页结果
        serl = PagerSerializer(instance=pager_roles, many=True)
        return Response(serl.data)

2、继承内置类自定义分页

from rest_framework.views import APIView
from rest_framework.pagination import PageNumberPagination
from api import models
from api.utils.serializers.pager import PagerSerializer


class MyPageNumberPagination(PageNumberPagination):
    """自定义分页类"""
    page_size = 2  # 设置一页显示2条数据
    # page_size_query_param = None  # 设置请求参数的key
    #  设置为size  可以在请求参数重置每页显示的数据条数
    page_size_query_param = "size"  # http://127.0.0.1:8082/api/v1/pager1/?size=3
    max_page_size = 5  # 设置每页最大显示的数据条数

    page_query_param = 'page'  # 获取页码 http://127.0.0.1:8082/api/v1/pager1/?page=2 获取第二页数据


class Pager1View(APIView):
    """分页显示"""
    def get(self, request, *args, **kwargs):

        roles = models.Role.objects.all()
        pg = MyPageNumberPagination()
        # 获取分页数据
        pager_roles = pg.paginate_queryset(queryset=roles, request=request, view=self)
        # 序列化分页结果
        serl = PagerSerializer(instance=pager_roles, many=True)

        # return Response(serl.data)

        # 还可以使用内置方法返回数据
        res = pg.get_paginated_response(serl.data)
        return res

3、LimitOffsetPagination类

from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.pagination import PageNumberPagination, LimitOffsetPagination
from api import models
from api.utils.serializers.pager import PagerSerializer

class Pager1View(APIView):
    """分页显示"""
    def get(self, request, *args, **kwargs):

        roles = models.Role.objects.all()
        pg = LimitOffsetPagination()  # 使用的是offset设置索引的ID
        # http://127.0.0.1:8082/api/v1/pager1/?offset=2  表示从第3条数据开始显示
        # http://127.0.0.1:8082/api/v1/pager1/?offset=2&limit=4  表示从第3条数据开始向后取4条
        # 获取分页数据
        pager_roles = pg.paginate_queryset(queryset=roles, request=request, view=self)
        # 序列化分页结果
        serl = PagerSerializer(instance=pager_roles, many=True)

        return Response(serl.data)

4、CursorPagination类

from rest_framework.views import APIView
from rest_framework.pagination import CursorPagination
from api import models
from api.utils.serializers.pager import PagerSerializer


class MyCursorPagination(CursorPagination):
    """自定义分页类"""
    cursor_query_param = 'cursor'
    page_size = 2
    ordering = 'id'  # 获取数据时的排序规则
    page_size_query_param = None
    max_page_size = None


class Pager1View(APIView):
    """分页显示"""
    def get(self, request, *args, **kwargs):

        roles = models.Role.objects.all()
        pg = MyCursorPagination()
        # 获取分页数据
        pager_roles = pg.paginate_queryset(queryset=roles, request=request, view=self)
        # 序列化分页结果
        serl = PagerSerializer(instance=pager_roles, many=True)

        res = pg.get_paginated_response(serl.data)
        return res

二、rest framework的视图

1、APIView

from django.conf.urls import url
from api import views

urlpatterns = [
    url(r'^(?P<version>[v1|2]+)/viewer/$', views.ViewerView.as_view()),
]

from rest_framework.views import APIView
from rest_framework.response import Response


class ViewerView(APIView):
    """继承APIView"""
    def get(self, request, *args, **kwargs):
        return Response("xxx")

2、GenericAPIView

from django.db import models


class UserGroup(models.Model):
    title = models.CharField(max_length=32)


class UserInfo(models.Model):
    user_type_choices = (
        (1, "普通用户"),
        (2, "vip"),
        (3, "svip"),
    )
    user_type = models.IntegerField(choices=user_type_choices)
    username = models.CharField(max_length=32, unique=True)
    password = models.CharField(max_length=64)
    group = models.ForeignKey(to="UserGroup", on_delete=models.CASCADE, null=True, blank=True)
    roles = models.ManyToManyField(to="Role", blank=True)


class UserToken(models.Model):
    user = models.OneToOneField(to="UserInfo")
    token = models.CharField(max_length=64)


class Role(models.Model):
    title = models.CharField(max_length=32)


class Order(models.Model):
    id = models.AutoField(primary_key=True)
    name = models.CharField(max_length=32)
    price = models.DecimalField(max_digits=5, decimal_places=2)
    create_time = models.DateTimeField(auto_now_add=True)
    user = models.ForeignKey(to="UserInfo", on_delete=models.CASCADE, null=True, blank=True)

from django.conf.urls import url
from api import views

urlpatterns = [
    url(r'^(?P<version>[v1|2]+)/viewer/$', views.ViewerView.as_view()),
]

from rest_framework import serializers
from api import models


class ViewSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Role
        fields = "__all__"

from rest_framework.generics import GenericAPIView
from rest_framework.response import Response
from rest_framework.pagination import PageNumberPagination

from api import models
from api.utils.serializers.view_serializer import ViewSerializer


class ViewerView(GenericAPIView):
    """继承GenericAPIView"""
    queryset = models.Role.objects.all()  # 指定要查询的数据
    serializer_class = ViewSerializer   # 序列化类
    pagination_class = PageNumberPagination  # 分页类

    def get(self, request, *args, **kwargs):
        roles = self.get_queryset()  # 获取数据
        pager = self.paginate_queryset(roles)  # 分页
        serl = self.get_serializer(instance=pager, many=True)  # 序列化
        return Response(serl.data)

3、GenericViewSet

继承了ViewSetMixin和GenericAPIView

from django.conf.urls import url
from api import views

urlpatterns = [
    url(r'^(?P<version>[v1|2]+)/viewer/$', views.ViewerView.as_view({'get': 'list'})),
]

from rest_framework.viewsets import GenericViewSet
from rest_framework.response import Response
from rest_framework.pagination import PageNumberPagination

from api import models
from api.utils.serializers.view_serializer import ViewSerializer


class ViewerView(GenericViewSet):
    """继承GenericViewSet"""
    queryset = models.Role.objects.all()  # 指定要查询的数据
    serializer_class = ViewSerializer  # 序列化类
    pagination_class = PageNumberPagination  # 分页类

    def list(self, request, *args, **kwargs):
        roles = self.get_queryset()  # 获取数据
        pager = self.paginate_queryset(roles)  # 分页
        serl = self.get_serializer(instance=pager, many=True)  # 序列化
        return Response(serl.data)

4、ListModelMixin、CreateModelMixin、GenericViewSet

ListModelMixin内部实现了list方法：

CreateModelMixin内部实现了create方法：

from django.conf.urls import url
from api import views

urlpatterns = [
    url(r'^(?P<version>[v1|2]+)/viewer/$', views.ViewerView.as_view({'get': 'list', 'post': 'create'})),
]

from rest_framework.viewsets import GenericViewSet
from rest_framework.mixins import ListModelMixin, CreateModelMixin
from rest_framework.pagination import PageNumberPagination

from api import models
from api.utils.serializers.view_serializer import ViewSerializer


class ViewerView(ListModelMixin, CreateModelMixin, GenericViewSet):
    """继承ListModelMixin、CreateModelMixin、GenericViewSet"""
    queryset = models.Role.objects.all()  # 指定要查询的数据
    serializer_class = ViewSerializer  # 序列化类
    pagination_class = PageNumberPagination  # 分页类

5、ModelViewSet

获取单条数据、更新数据、删除数据时，URL中需要传递要操作的数据的ID

from django.conf.urls import url
from api import views

urlpatterns = [
    url(r'^(?P<version>[v1|2]+)/viewer/(?P<pk>d+)$', views.ViewerView.as_view({'get': 'retrieve',
                                                                                'post': 'create',
                                                                                'delete': 'destroy',
                                                                                'put': 'update',
                                                                                'patch': 'partial_update'})),
]

from rest_framework.viewsets import ModelViewSet
from rest_framework.pagination import PageNumberPagination

from api import models
from api.utils.serializers.view_serializer import ViewSerializer


class ViewerView(ModelViewSet):
    """继承ModelViewSet"""
    queryset = models.Role.objects.all()  # 指定要查询的数据
    serializer_class = ViewSerializer  # 序列化类
    pagination_class = PageNumberPagination  # 分页类

6、当使用GenericViewSet类时，会执行它父类GenericAPIView里面的get_object方法，这个方法执行了check_object_permissions方法来对对象的权限进行校验：

三、rest framework的路由

url(r'^(?P<version>[v1|2]+)/viewer/$', views.ViewerView.as_view()) 
# http://127.0.0.1:8080/api/v2/viewer/


url(r'^(?P<version>[v1|2]+)/viewer/$', views.ViewerView.as_view({'get': 'list', 'post': 'create'}))  
# http://127.0.0.1:8080/api/v2/viewer/
# http://127.0.0.1:8080/api/v2/viewer/?format=json  get传参的方式


url(r'^(?P<version>[v1|2]+)/viewer.(?P<format>w+)$', views.ViewerView.as_view({'get': 'list', 'post': 'create'}))
# http://127.0.0.1:8080/api/v2/viewer.json  将参数写到路径里面

自动生成路由：

from django.conf.urls import url, include
from rest_framework import routers
from api import views


router = routers.DefaultRouter()
router.register(r"role", views.ViewerView)  # url前缀，视图名称
router.register(r"group", views.ViewerView)

urlpatterns = [
    url(r'^(?P<version>[v1|2]+)/', include(router.urls)),
]

自动生成的路由：

可以通过http://127.0.0.1:8080/api/v2/role/    http://127.0.0.1:8080/api/v2/role.json等方式进行访问

四、rest framework的渲染器

1、局部配置

urlpatterns = [
    url(r'^(?P<version>[v1|2]+)/test/$', views.TestView.as_view()),
]

from rest_framework import serializers
from api import models


class ViewSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Role
        fields = "__all__"

from rest_framework.views import APIView
from rest_framework.viewsets import ModelViewSet
from rest_framework.response import Response
from rest_framework.pagination import PageNumberPagination
from rest_framework.renderers import JSONRenderer, BrowsableAPIRenderer, AdminRenderer

from api import models
from api.utils.serializers.view_serializer import ViewSerializer


class TestView(APIView):
    renderer_classes = [JSONRenderer, BrowsableAPIRenderer]  # 渲染数据格式的类 http://127.0.0.1:8080/api/v2/test/?format=json
    # renderer_classes = [AdminRenderer, BrowsableAPIRenderer]  # 渲染数据格式的类 http://127.0.0.1:8080/api/v2/test/?format=admin

    def get(self, request, *args, **kwargs):
        roles = models.Role.objects.all()
        pg = PageNumberPagination()
        pager_roles = pg.paginate_queryset(queryset=roles, request=request, view=self)
        serl = ViewSerializer(instance=pager_roles, many=True)
        return Response(serl.data)

2、全局配置

在项目的settings里面：