Django Rest Framework(二)
•基于Django
先创建一个django项目，在项目中创建一些表，用来测试rest framework的各种组件
models.py
class UserInfo(models.Model): """用户信息表""" user = models.CharField(max_length=32) pwd = models.CharField(max_length=32) class UserToken(models.Model): """用户token表""" user = models.OneToOneField(to="UserInfo", on_delete=models.CASCADE) token = models.CharField(max_length=64) class Courses(models.Model): """ 课程表 """ name = models.CharField(verbose_name="课程名称", max_length=32) course_img = models.CharField(verbose_name="课程图片", max_length=64) level_choices = ( (1, "初级"), (2, "中级"), (3, "高级"), ) level = models.IntegerField(verbose_name="难度", choices=level_choices, default=1) def __str__(self): return self.name class CourseDetail(models.Model): """课程详细表""" course = models.OneToOneField(to="Courses", on_delete=models.CASCADE) slogan = models.CharField(verbose_name="口号", max_length=255) why = models.CharField(verbose_name="为什么要学", max_length=255) recommend_courses = models.ManyToManyField(verbose_name="推荐课程", to="Courses", related_name="rc") # related_name设置反向查询的字段，有多个关联时指定某个字段进行反向查询 def __str__(self): return "课程详细：" + self.course.title class Chapter(models.Model): """ 课程章节表 """ num = models.IntegerField(verbose_name="章节") name = models.CharField(verbose_name="章节名称", max_length=32) course = models.ForeignKey(verbose_name="所属课程", to="Courses", related_name='coursechapters', on_delete=models.CASCADE) def __str__(self): return self.name
urls.py
from django.contrib import admin from django.urls import path, include, re_path urlpatterns = [ path('admin/', admin.site.urls), re_path(r'^api/(?P<version>\w+)/', include("api.urls")), ]
api/urls.py
from django.urls import re_path
from api.views import courses, account, micro
urlpatterns = [
re_path(r'^courses/$', courses.CoursesView.as_view({"get": "list"})),
re_path(r'^courses/(?P<pk>\d+)/', courses.CoursesView.as_view({"get": "retrieve"})),
re_path(r'^micro/$', micro.MicroView.as_view({"get": "list"})),
re_path(r'^login/$', account.LoginView.as_view()),
]
•基本流程
请求到来之后，都要执行dispatch方法，dispatch方法根据请求方式不同触发不同的方法，返回不同的内容
url.py
1 from django.conf.urls import url, include 2 from api.views import TestView 3 4 urlpatterns = [ 5 url(r'^test/', TestView.as_view()), 6 ]
views.py
1 from rest_framework.views import APIView 2 from rest_framework.response import Response 3 4 5 class TestView(APIView): 6 def dispatch(self, request, *args, **kwargs): 7 """ 8 请求到来之后，都要执行dispatch方法，dispatch方法根据请求方式不同触发 get/post/put等方法 9 10 注意：dispatch方法有好多好多的功能 11 """ 12 return super().dispatch(request, *args, **kwargs) 13 14 def get(self, request, *args, **kwargs): 15 return Response('GET请求，响应内容') 16 17 def post(self, request, *args, **kwargs): 18 return Response('POST请求，响应内容') 19 20 def put(self, request, *args, **kwargs): 21 return Response('PUT请求，响应内容')
•认证组件
给micro添加需要认证才能访问的权限
micro.py
# _*_ coding=utf-8 _*_ from rest_framework.views import APIView from rest_framework.response import Response from rest_framework.viewsets import ViewSetMixin from api.auth.auth import MicroAuth class MicroView(ViewSetMixin, APIView): # 给micro添加认证后才能访问的组件 authentication_classes = [MicroAuth] def list(self, request, *args, **kwargs): ret = {'code': 1000, 'data': '学习中心'} return Response(ret)
auth.py
# _*_ coding=utf-8 _*_ from rest_framework.authentication import BaseAuthentication from rest_framework.exceptions import AuthenticationFailed from api.models import * class MicroAuth(BaseAuthentication): """从token表读取token进行认证""" def authenticate(self, request): token = request.query_params.get('token') obj = UserToken.objects.filter(token=token).first() if not obj: raise AuthenticationFailed({'code': 10001, 'error': '认证失败'}) return (obj.user.user, obj)
全局设置：
上述操作中均是对单独视图进行特殊配置，如果想要对全局进行配置，则需要再配置文件中写入即可
•访问频率控制
给course添加频率限制，同一个IP，60秒内访问不超过3次
•使用自定义类进行访问频率控制，继承BaseThrottle类
myThrottle.py
import time from rest_framework.throttling import BaseThrottle class MyThrottle(BaseThrottle): """IP访问频率组件 限制60秒内访问3次""" def __init__(self): self.history = None def allow_request(self, request, view): current_time = time.time() ip = request.META.get('REMOTE_ADDR') print(ip) if ip not in visit_code: # 如果是第一次访问就把此ip的访问时间存入visit_code中，返回True，不限制 visit_code[ip] = [current_time, ] return True # 如果不是第一次访问，就获取其ip的访问时间[time1,time2..] history = visit_code.get(ip) self.history = history # print(history,visit_code) while history and history[-1] < current_time - 60: # 判断第一次访问时间和当前时间是否超过60s，超过则删除 history.pop() if len(history) < 3: # history里面的元素小于3个则把当前时间添加进去，方法True history.insert(0, current_time) return True # else: # 可以不写 # return False def wait(self): """需要等待多少时间才能访问""" current_time = time.time() return 60 - (current_time - self.history[-1])
在CoursesView类添加访问频率组件
class CoursesView(ViewSetMixin, APIView): # 频率访问组件 throttle_classes = [MyThrottle,]
•使用rest framework内置频率控制组件
myThrottle.py
from rest_framework.throttling import SimpleRateThrottle class VisitThrottle(SimpleRateThrottle): """内置ip频率组件,需要在settings里面设置参数""" scope = "visit_rate" def get_cache_key(self, request, view): return self.get_ident(request)
settings.py
REST_FRAMEWORK = { "DEFAULT_THROTTLE_CLASSES": ["api.myThrottle.VisitThrottle", ], "DEFAULT_THROTTLE_RATES": { "visit_rate": "5/m", # 这个参数就是频率类中定义的那个参数scope， 其中第一个数字5表示5次， # 后面的m表示一分钟，还有s，一秒， h, 一小时， d, 一天 } }
•权限控制
给TestView添加权限认证
views.py
# -*- coding:utf-8 -*- from rest_framework.views import APIView from rest_framework.response import Response from rest_framework.permissions import BasePermission from rest_framework.request import Request class TestPermission(BasePermission): message = "权限验证失败" def has_permission(self, request, view): """ 判断是否有权限访问当前请求 Return `True` if permission is granted, `False` otherwise. :param request: :param view: :return: True有权限；False无权限 """ if request.user == "管理员": return True # GenericAPIView中get_object时调用 def has_object_permission(self, request, view, obj): """ 继承GenericAPIView，并在其中使用get_object时获取对象时，触发单独对象权限验证 Return `True` if permission is granted, `False` otherwise. :param request: :param view: :param obj: :return: True有权限；False无权限 """ if request.user == "管理员": return True class TestView(APIView): # 认证的动作是由request.user触发 # 添加权限 permission_classes = [TestPermission, ] def get(self, request, *args, **kwargs): # self.dispatch print(request.user) print(request.auth) return Response('GET请求，响应内容')
全局设置
settings.py
REST_FRAMEWORK = { "DEFAULT_PERMISSION_CLASSES": [ "api.views.TestPermission", ], }
•序列化
对用户请求的数据进行序列化
a.自动生成字段
# _*_ coding=utf-8 _*_ from django.urls import re_path from api.views import courses urlpatterns = [ re_path(r'^courses/$', courses.CoursesView.as_view({"get": "list"})), ]
from rest_framework.views import APIView from rest_framework.response import Response from rest_framework.viewsets import ViewSetMixin from rest_framework import serializers from api.models import * class CoursesSerializers(serializers.ModelSerializer): """课程序列化""" level = serializers.CharField(source='get_level_display') # 获取choices的中文 class Meta: model = Course # 指定表 fields = "__all__" # 使用自动生成的字段 class CoursesView(ViewSetMixin, APIView): def list(self, request, *args, **kwargs): ret = {"code": 1000, "data": None} try: course_list = Course.objects.all() course_data = CoursesSerializers(instance=course_list, many=True) ret["data"] = course_data.data except Exception as e: ret["code"] = 1001 ret["error"] = "获取失败" return Response(ret)
b.使用自定义字段
# _*_ coding=utf-8 _*_ from django.urls import re_path from api.views import courses urlpatterns = [ re_path(r'^courses/$', courses.CoursesView.as_view({"get": "list"})), re_path(r'^courses/(?P<pk>\d+)/', courses.CoursesView.as_view({"get": "retrieve"})), ]
from rest_framework import serializers from rest_framework.views import APIView from rest_framework.response import Response from rest_framework.viewsets import ViewSetMixin from api.serializers.courses_serializers import * from api.models import * class CourseDetailSerializers(serializers.ModelSerializer): """课程详细序列化""" # OneToOne/fk/choice等字段查询某一条记录时适用： 自定义要序列化的字段，关联的表：表名.字段, name = serializers.CharField(source='course.name') level = serializers.CharField(source='course.get_level_display') # 获取choice类型对应的中文 # ManyToMany，fk查询多条记录适用: recommend_courses = serializers.SerializerMethodField() chapters = serializers.SerializerMethodField() class Meta: model = CourseDetail # 添加自定义字段 fields = ['name', 'level', 'recommend_courses', 'chapters'] def get_recommend_courses(self, obj): # 获取所有的课程,obj指的是CourseDetail,recommends字段数据为此函数的返回值 course_list = obj.recommend_course.all() return [{"id": i.id, "title": i.name} for i in course_list] def get_chapters(self, obj): # 反向查询时如果定义了related_name，要使用related_name的值进行查询 chapters = obj.course.coursechapters.all() return [{"id": i.id, "name": i.name} for i in chapters] class CoursesView(ViewSetMixin, APIView): def list(self, request, *args, **kwargs): ret = {"code": 1000, "data": None} try: course_list = Course.objects.all() course_data = CoursesSerializers(instance=course_list, many=True) ret["data"] = course_data.data except Exception as e: ret["code"] = 1001 ret["error"] = "获取失败" return Response(ret) def retrieve(self, request, *args, **kwargs): ret = {"code": 1000, "data": None} try: # 课程id pk = kwargs.get("pk") # 课程详细对象 obj = CourseDetail.objects.filter(course_id=pk).first() course_detail = CourseDetailSerializers(instance=obj, many=False) ret["data"] = course_detail.data except Exception as e: ret["code"] = 1001 ret["error"] = "获取失败" return Response(ret)
•分页器
设置页码进行分页
# _*_ coding=utf-8 _*_ from django.urls import re_path from api.views import courses urlpatterns = [ re_path(r'^courses/$', courses.CoursesView.as_view({"get": "list"})), re_path(r'^courses/(?P<pk>\d+)/', courses.CoursesView.as_view({"get": "retrieve"})), ]
# -*- coding:utf-8 -*- from rest_framework.views import APIView from rest_framework import serializers from api import models from rest_framework.pagination import PageNumberPagination class MyPagination(PageNumberPagination): # 默认每页显示的数据条数 page_size = 1 # 获取URL参数中设置的每页显示数据条数 page_size_query_param = 'page_size' # 获取URL参数中传入的页码key page_query_param = 'page' # 最大支持的每页显示的数据条数 max_page_size = 1 class CourseSerializer(serializers.ModelSerializer): class Meta: model = models.Course fields = "__all__" class CoursesViewSet(APIView): def list(self, request, *args, **kwargs): course_list = models.Course.objects.all().order_by('-id') # 实例化分页对象，获取数据库中的分页数据 paginator = MyPagination() page_course_list = paginator.paginate_queryset(course_list, self.request, view=self) # 序列化对象 serializer = CourseSerializer(page_user_list, many=True) # 生成分页和数据 response = paginator.get_paginated_response(serializer.data) return response
使用自动生成url
urls.py
from rest_framework import routers from api.views import * router = routers.DefaultRouter() router.register('courses', CoursesViewSet)
便捷使用分页器
views.py
from rest_framework import viewsets from rest_framework import serializers from api.models import * class CoursesSerializers(serializers.ModelSerializer): """课程序列化""" level = serializers.CharField(source='get_level_display') class Meta: model = Courses fields = "__all__" class CoursesViewSet(viewsets.ModelViewSet): # 指定已经写好的分页器 pagination_class = MyPagination queryset = Courses.objects.all().order_by('id') # 使用分页器要排序 serializer_class = CoursesSerializersModel
