drf 三

作者: 吃可爱长大鸭 | 来源:发表于2021-11-19 11:01 被阅读0次

    目录

    1.序列化many参数源码分析(了解)
    2.局部全局钩子的源码分析(了解)
    3.序列化对象.data
    4.两个视图基类
    5.五个视图扩展类
    6.九个视图子类
    7.视图集
    8.GenericAPIView基类(初级方法)
    9.GenericAPIView视图扩展类(中级方法)
    10.GenericAPIView视图子类类 (高级方法)
    11.GenericAPIView视图集类 (超级方法)
    12.总结
    

    1.序列化many参数源码分析(了解)

    1 序列化类实例化的时候,传了many,序列化多条,不传,就序列化单条
    #many=True,实例化得到的对象是ListSerializer
    ser=serializer.BookModelSerializer(instance=qs,many=True)
    print(type(ser))
    #rest_framework.serializers.ListSerializer
    # 列表中套了很多BookModelSerializer
    
    #many=False,实例化得到的对象是BookModelSerializer
    ser=serializer.BookModelSerializer(instance=book)
    print(type(ser))
    #app01.serializer.BookModelSerializer
    
    
    
    类实例化:在执行__init__之前,先执行了__new__生成一个空对象(决定了是哪个类的对象)
    在__new__中进行判断,如果many=True,就返回ListSerializer的对象
    

    2.局部全局钩子的源码分析(了解)

    is_valid()
    判断_validated_data如果没有
    执行了 self.run_validation(self.initial_data)
    目前在BaseSerializer,如果按住ctrl点击,会直接进到它父类的run_validation,进到Field,不是真正执行的方法
    
    我们需要从头找,实际上是Serializer类的run_validation
    def run_validation(self, data=empty):
        value = self.to_internal_value(data)#字段自己的校验和局部钩子
        try:
            self.run_validators(value) 
            value = self.validate(value) # 全局钩子
            assert value is not None, 
            except (ValidationError, DjangoValidationError) as exc:
                raise ValidationError(detail=as_serializer_error(exc))
    
                return value
    局部钩子是在  to_internal_value执行的
    def to_internal_value(self, data):
        for field in fields:
            validate_method = getattr(self, 'validate_' + field.field_name, None)
            if validate_method is not None:
                validated_value = validate_method(validated_value)
                
                
                
    ##总结:
    is_valid---》BaseSerializer的is_valid--》执行了self.run_validation(self.initial_data)---》Serializer的run_validation---》self.to_internal_value(data):局部钩子|||
    value = self.validate(value) :全局钩子
    
    self.to_internal_value(data):局部钩子----》getattr(self, 'validate_' + field.field_name, None)
                    
    

    3.序列化对象.data

    序列化对象.data方法--调用父类data方法---调用对象自己的to_representation(自定义的序列化类无此方法,去父类找)
    Serializer类里有to_representation方法,for循环执行attribute = field.get_attribute(instance)
    再去Field类里去找get_attribute方法,self.source_attrs就是被切分的source,然后执行get_attribute方法,source_attrs
    当参数传过去,判断是方法就加括号执行,是属性就把值取出来
    

    4.两个视图基类

    1 APIView
    2 GenericAPIView(APIView):做了一些封装
        -属性:
            queryset 
            serializer_class
        -方法:
            get_queryset:获取qs数据
            get_object:获取一条数据的对象
            get_serializer:以后使用它来实例化得到ser对象
            get_serializer_class:获取序列化类,注意跟上面区分
    

    5.五个视图扩展类

    # 5个视图扩展类(rest_framework.mixins)
    CreateModelMixin:create方法创建一条
    DestroyModelMixin:destory方法删除一条
    ListModelMixin:list方法获取所有
    RetrieveModelMixin:retrieve获取一条
    UpdateModelMixin:update修改一条
    

    6.九个视图子类

    # 9个子类视图(rest_framework.generics)
    1 ListAPIView (查所有) 
    2 RetrieveAPIView (查一个) 
    3 DestroyAPIView(删一个)
    4 UpdateAPIView (改一个)
    5 CreateAPIView (增一个)
    6 ListCreateAPIView (查所有+增一个)
    7 RetrieveDestroyAPIView (查一个+删一个)
    8 RetrieveUpdateAPIView (查一个+改一个)
    9 RetrieveUpdateDestroyAPIView (查一个+删一个+改一个)
    
    CreateAPIView:继承CreateModelMixin,GenericAPIView,有post方法,新增数据
    DestroyAPIView:继承DestroyModelMixin,GenericAPIView,有delete方法,删除数据
    ListAPIView:继承ListModelMixin,GenericAPIView,有get方法获取所有
    UpdateAPIView:继承UpdateModelMixin,GenericAPIView,有put和patch方法,修改数据
    RetrieveAPIView:继承RetrieveModelMixin,GenericAPIView,有get方法,获取一条
    
    ListCreateAPIView:继承ListModelMixin,CreateModelMixin,GenericAPIView,有get获取所有,post方法新增
    RetrieveDestroyAPIView:继承RetrieveModelMixin,DestroyModelMixin,GenericAPIView,有get方法获取一条,delete方法删除
    RetrieveUpdateAPIView:继承RetrieveModelMixin,UpdateModelMixin,GenericAPIView,有get获取一条,put,patch修改
    RetrieveUpdateDestroyAPIView:继承RetrieveModelMixin,UpdateModelMixin,DestroyModelMixin,GenericAPIView,有get获取一条,put,patch修改,delete删除
    

    7.视图集

    ViewSetMixin:重写了as_view 
    ViewSet:     继承ViewSetMixin和APIView
    
    GenericViewSet:继承ViewSetMixin, generics.GenericAPIView
    ModelViewSet:继承mixins.CreateModelMixin,mixins.RetrieveModelMixin,mixins.UpdateModelMixin,mixins.DestroyModelMixin,mixins.ListModelMixin,GenericViewSet
    ReadOnlyModelViewSet:继承mixins.RetrieveModelMixin,mixins.ListModelMixin,GenericViewSet
    

    8.GenericAPIView基类(初级方法)

    8.1 视图

    # 只需要修改定义方法的数据和类
    class PublishViews(GenericAPIView):
        queryset = models.Publish.objects.all() # 序列化的数据
        serializer_class = serializer.PublishModelSerializer # 序列化的类
    
        def get(self, request, *args, **kwargs):
            response = {'status': 200, 'msg': '查询'}
            try:
                qs = self.get_queryset()
                ser = self.get_serializer(instance=qs, many=True)  # many全部
                # return Response(ser.data)
                # book.data字典加入到data列表里
                response['data'] = ser.data
            except Exception as e:
                # 返回错误信息
                response['msg'] = str(e)
            return Response(response)
    
        # 增加
        def post(self, request, *args, **kwargs):
            response = {'status': 200, 'msg': '新增'}
            try:
                ser = self.get_serializer(data=request.data)
                if ser.is_valid():
                    ser.save()
                    response['data'] = ser.data
                else:
                    response['msg'] = ser.errors
            except Exception as e:
                response['msg'] = str(e)
            return Response(response)
    
    
    class PublishViewsId(GenericAPIView):
        queryset = models.Publish.objects.all() # 序列化的数据
        serializer_class = serializer.PublishModelSerializer # 序列化的类
    
        # 查询一个
    
        def get(self, request, *args, **kwargs):
            response = {'status': 200, 'msg': '成功'}
            try:
                # 取出id
                obj = self.get_object()
                # 序列化
                ser = self.get_serializer(instance=obj)
                # book.data字典加入到data列表里
                response['data'] = ser.data
            except Exception as e:
                # 返回错误信息
                response['msg'] = str(e)
            return Response(response)
    
        # 修改数据
        def put(self, request, *args, **kwargs):
            response = {'status': 200, 'msg': '成功'}
            try:
                # 取出id
                obj = self.get_object()
                # 拿到id号反序列化
                ser = self.get_serializer(instance=obj, data=request.data)
                # 校验
                if ser.is_valid():
                    ser.save()
                    response['data'] = ser.data
                else:
                    response['msg'] = ser.errors
            except Exception as e:
                # 返回错误信息
                response['msg'] = str(e)
            return Response(response)
    
        # 删除
        def delete(self, request, *args, **kwargs):
            # 查询到id号
            res = self.get_object().delete()
            # 判断第一个删除
            if res[0] > 0:
                return Response('')
            else:
                return Response('删除的不存在')
    

    8.2 序列化类

    from rest_framework import serializers
    from restful import models
    
    # 继承ModelSerializer类
    class PublishModelSerializer(serializers.ModelSerializer):
        class Meta:
            model = models.Publish
            # __all__ 查询所有
            fields = '__all__'
    

    8.3 路由

    from restful import views
    urlpatterns = [
        path('publish/<int:pk>/', views.PublishViewsId.as_view()),
        path('publish/', views.PublishViews.as_view()),
    ]
    

    8.4 settings配置app(注意记得配置数据库也可以用自带sqllite3)

    INSTALLED_APPS = [
        'rest_framework'
    ]
    

    8.5 models 表模型(注意迁移)

    from django.db import models
    
    
    class Book(models.Model):
        nid = models.AutoField(primary_key=True)
        name = models.CharField(max_length=32)
        price = models.DecimalField(max_digits=5, decimal_places=2)
        publish_date = models.DateField()
    
        publish = models.ForeignKey(to='Publish', to_field='nid', on_delete=models.CASCADE)
        authors = models.ManyToManyField(to='Author')
    
        def __str__(self):
            return self.name
    
    
    class Author(models.Model):
        nid = models.AutoField(primary_key=True)
        name = models.CharField(max_length=32)
        age = models.IntegerField()
        author_detail = models.OneToOneField(to='AuthorDatail', to_field='nid', unique=True, on_delete=models.CASCADE)
    
        def __str__(self):
            return self.name
    
    
    class AuthorDatail(models.Model):
        nid = models.AutoField(primary_key=True)
        telephone = models.BigIntegerField()
        birthday = models.DateField()
        addr = models.CharField(max_length=64)
    
        def __str__(self):
            return self.addr
    
    
    class Publish(models.Model):
        nid = models.AutoField(primary_key=True)
        name = models.CharField(max_length=32)
        city = models.CharField(max_length=32)
        email = models.EmailField()
    
        def __str__(self):
            return self.name
    

    8.6 admin配置(注意创建用户 createsuperuser)

    from django.contrib import admin
    from restful import models
    
    admin.site.register(models.Book)
    admin.site.register(models.Author)
    admin.site.register(models.AuthorDatail)
    admin.site.register(models.Publish)
    

    9.GenericAPIView视图扩展类(中级方法,其它序列化类路由配置同上)

    from restful import models
    from restful import serializer
    from rest_framework.generics import GenericAPIView
    from rest_framework.mixins import ListModelMixin,CreateModelMixin,UpdateModelMixin,DestroyModelMixin,RetrieveModelMixin
    
    
    class PublishViews(GenericAPIView, ListModelMixin, CreateModelMixin):
        queryset = models.Publish.objects.all()  # 序列化的数据
        serializer_class = serializer.PublishModelSerializer  # 序列化的类
    
        def get(self, request, *args, **kwargs):
            return self.list(request, *args, **kwargs)
    
        def post(self, request, *args, **kwargs):
            return self.create(request, *args, **kwargs)
    
    
    class PublishViewsId(GenericAPIView, RetrieveModelMixin, DestroyModelMixin, UpdateModelMixin):
        queryset = models.Publish.objects.all()  # 序列化的数据
        serializer_class = serializer.PublishModelSerializer  # 序列化的类
        
        def get(self, request, *args, **kwargs):
            return self.retrieve(request, *args, **kwargs)
    
        def put(self, request, *args, **kwargs):
            return self.update(request, *args, **kwargs)
    
        def delete(self, request, *args, **kwargs):
            return self.delete(request, *args, **kwargs)
    

    10.GenericAPIView视图子类类(高级方法,其它序列化类路由配置同上)

    from rest_framework.generics import ListAPIView,CreateAPIView,RetrieveAPIView,UpdateAPIView,DestroyAPIView,
    from rest_framework.generics import ListCreateAPIView,RetrieveUpdateAPIView,RetrieveDestroyAPIView,RetrieveUpdateDestroyAPIView
    from restful import models
    from restful import serializer
    
    class PublishViews(ListCreateAPIView):
        queryset = models.Publish.objects.all() # 序列化的数据
        serializer_class = serializer.PublishModelSerializer # 序列化的类
    
    
    class PublishViewsId(RetrieveUpdateDestroyAPIView):
        queryset = models.Publish.objects.all()  # 序列化的数据
        serializer_class = serializer.PublishModelSerializer  # 序列化的类
    

    11.GenericAPIView视图集类 (超级方法,序列化类表模型配置同上)

    11.1 视图

    from rest_framework.viewsets import ModelViewSet, ReadOnlyModelViewSet
    from rest_framework.viewsets import ViewSet, GenericViewSet, ViewSetMixin
    
    # ModelViewSet五个接口都有
    # ReadOnlyModelViewSet 只有读的两个接口
    class PublishViews(ModelViewSet):
        queryset = models.Publish.objects.all()  # 序列化的数据
        serializer_class = serializer.PublishModelSerializer  # 序列化的类
    

    11.2 路由

    from restful import views
    urlpatterns = [
        path('publish/', views.PublishViews.as_view({'get':'list', 'post':'create'})),
        path('publish/<int:pk>/', views.PublishViews.as_view({'get':'retrieve', 'put':'update', 'delete':'destroy'})),
    ]
    

    12 总结

    1 序列化器源码
        -many参数控制,在__new__中控制了对象的生成
        -局部和全局钩子源码:is_valid--》找self.方法一定要从根上找
        -source参数是如何执行的:‘publish.name’,'方法'
    
    2 视图:
        -2个视图基类
        -5个视图扩展类
        -9个视图子类
        -视图集
            -ViewSetMixin
            -ViewSet, GenericViewSet
            -ModelViewSet, ReadOnlyModelViewSet
        
    3 视图类的继承原则
        -如果不涉及数据库操作:继承APIView
        -如果想让路由可以映射:继承ViewSetMixin
        -如果不涉及数据库操作,又要让路由可以映射:继承ViewSet
        -比如发邮件接口,发短信接口
        
        
        -如果涉及到数据库操作:继承GenericAPIView
        -如果想让路由可以映射:继承ViewSetMixin
        -如果涉及数据库操作,又要让路由可以映射:继承GenericViewSet
        -如果涉及数据库操作,又要让路由可以映射,还要能新增:继承GenericViewSet+CreateModelMixin或者继承ViewSetMixin+CreateAPIView
        
        -如果只涉及到数据库操作和新增:继承CreateAPIView
        
        -路由有映射,数据库操作,3个接口(查一个,删一个改一个)
        
    4 ViewSetMixin:路由的写法就特殊了
        
        
        
    5 类实例化,先执行了元类的__call__:调用了这个类的__new__,生成一个空对象,调用了类的__init__,完成了对象的初始化
    6 对象()---->会触发类的 __call__
    7 类()----->会触发类的类(元类)的__call__
    
    

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