• ListModelSerializer模块


    ListModelSerializer模块

    一 、自定义反序列化字段

    # 一些只参与反序列化的字段,但是不是与数据库关联的
    # 在序列化类中规定,并在校验字段时从校验的参数字典中剔除
    class PublishModelSerializer(serializers.ModelSerializer):
        # 自定义不入库的 反序列化 字段
        re_name = serializers.CharField(write_only=True)
        class Meta:
            model = models.Publish
            fields = ('name', 're_name', 'address')
        def validate(self, attrs):
            name = attrs.get('name')
            re_name = attrs.pop('re_name')  # 剔除
            if name != re_name:
                raise serializers.ValidationError({'re_name': '确认名字有误'})
            return attrs
            
    

    二 、模型类中自定义序列化深度

    # model类中自定义插拔的外键序列化字段,可以采用外键关联表的序列化类来完成深度查询
    class Book(BaseModel):
        # ...
        @property
        def publish_detail(self):
            from . import serializers
            data = serializers.PublishModelSerializer(self.publish).data
            return data
            
    

    三 、接口操作总结

    # 单查群查、单删群删、单增群增、单改群改
    
    

    3.1 路由层:api/url.py

    from django.conf.urls import url
    from . import views
    urlpatterns = [
        # ...
        url(r'^v3/books/$', views.BookV3APIView.as_view()),
        url(r'^v3/books/(?P<pk>.*)/$', views.BookV3APIView.as_view()),
    ]
    
    

    3.2模型层:api/models.py

    # 修改部分:取消book类 name 与 publish 联合唯一,
    from django.db import models
    from utils.model import BaseModel
    class Book(BaseModel):
        name = models.CharField(max_length=64)
        price = models.DecimalField(max_digits=5, decimal_places=2)
        img = models.ImageField(upload_to='img', default='img/default.png')
        publish = models.ForeignKey(to='Publish', null=True,
                                    related_name='books',
                                    db_constraint=False,
                                    on_delete=models.DO_NOTHING,
                                    )
        authors = models.ManyToManyField(to='Author', null=True,
                                         related_name='books',
                                         db_constraint=False,
                                         )
    
        @property
        def publish_name(self):
            return self.publish.name
    
        @property
        def authors_info(self):
            author_list = []
            for author in self.authors.all():
                author_list.append({
                    'name': author.name,
                    'age': author.age,
                    'mobile': author.detail.mobile
                })
            return author_list
    
        @property
        def publish_bac(self):
            from . import serializers
            data = serializers.PublishModelSerializer(self.publish).data
            return data
    
        class Meta:
            db_table = 'old_boy_book'
            verbose_name = '书籍'
            verbose_name_plural = verbose_name
            # 联合唯一
            # unique_together = ('name', 'publish')
    
        def __str__(self):
            return self.name
    
    
    class Publish(BaseModel):
        name = models.CharField(max_length=64)
        address = models.CharField(max_length=64)
    
        class Meta:
            db_table = 'old_boy_publish'
            verbose_name = '出版社'
            verbose_name_plural = verbose_name
    
        def __str__(self):
            return self.name
    
    
    class Author(BaseModel):
        name = models.CharField(max_length=64)
        age = models.IntegerField()
    
        @property
        def mobile(self):
            return self.detail.mobile
    
        class Meta:
            db_table = 'old_boy_author'
            verbose_name = '作者'
            verbose_name_plural = verbose_name
    
        def __str__(self):
            return self.name
    
    
    class AuthorDetail(BaseModel):
        mobile = models.CharField(max_length=11)
    
        author = models.OneToOneField(to='Author', null=True,
                                      related_name='detail',
                                      db_constraint=False,
                                      on_delete=models.CASCADE
                                      )
    
        class Meta:
            db_table = 'old_boy_author_detail'
            verbose_name = '作者详情'
            verbose_name_plural = verbose_name
    
        def __str__(self):
            return '%s的详情' % self.author.name
            
    

    3.3 序列化层

    api/serializers.py

    # 群增与群改反序列化实现
    # 1)ModelSerializer默认不通过群改功能,需要在Meta中设置 list_serializer_class
    # 2)自定义ListSerializer子类,重写update方法,将子类绑定给 list_serializer_class
    # 3)重写update方法中通过 代表要更新的对象们instance 及 提供的更新数据们validated_data
    #       得到 更新后的对象们instance 返回
    class BookV3ListSerializer(serializers.ListSerializer):
        def update(self, instance, validated_data):
            '''
            :param instance: [book_obj1, ..., book_obj2]
            :param validated_data: [{更新数据的字段}, ..., {更新数据的字段}]
            :return: [book_new_obj1, ..., book_new_obj2]
            '''
            for index, obj in enumerate(instance):  # type: int, models.Book
                # 单个对象数据更新 - 一个个属性更新值
                for attr, value in validated_data[index].items():
                    # 对象有更新数据字典的key对应的属性,才完成该属性的值更新
                    if hasattr(obj, attr):
                        setattr(obj, attr, value)
                # 信息同步到数据库
                obj.save()
            return instance
    
    class BookV3ModelSerializer(serializers.ModelSerializer):
        class Meta:
            model = models.Book
            fields = ('name', 'price', 'publish', 'authors', 'img', 'publish_name', 'authors_info')
            list_serializer_class = BookV3ListSerializer
            extra_kwargs = {
                'publish': {
                    'required': True,
                    'write_only': True
                },
                'authors': {
                    'required': True,
                    'write_only': True
                },
                'img': {
                    'read_only': True
                }
            }
        def validate_name(self, value):
            if 'sb' in value:
                raise serializers.ValidationError('书名有敏感词汇')
            return value
        def validate(self, attrs):
            name = attrs.get('name')
            publish = attrs.get('publish')
            if models.Book.objects.filter(name=name, publish=publish):
                raise serializers.ValidationError({'book': '书籍以存在'})
            return attrs
            
    

    3.4 视图层

    api/views.py

    class BookV3APIView(APIView):
        # 单查群查
        def get(self, request, *args, **kwargs):
            pk = kwargs.get('pk')
            if pk:
                book_obj = models.Book.objects.filter(is_delete=False, pk=pk).first()
                if not book_obj:
                    return APIResponse(1, 'pk error')
                book_ser = serializers.BookV3ModelSerializer(book_obj)
                return APIResponse(0, 'ok', results=book_ser.data)
            book_query = models.Book.objects.filter(is_delete=False).all().order_by('-id')
            book_ser = serializers.BookV3ModelSerializer(book_query, many=True)
            return APIResponse(0, 'ok', results=book_ser.data)
        
        
        # 单增群增
        def post(self, request, *args, **kwargs):
            # 单增 /books/  data  {}
            # 群增 /books/  data  [{}, ..., {}]
            request_data = request.data
            if isinstance(request_data, dict):
                data = [request_data, ]
            elif isinstance(request_data, list):
                data = request_data
            else:
                return APIResponse(1, '数据格式有误')
            book_ser = serializers.BookV3ModelSerializer(data=data, many=True)
            if book_ser.is_valid():
                book_obj_list = book_ser.save()
                return APIResponse(0, 'ok',
                    results=serializers.BookV3ModelSerializer(book_obj_list, many=True).data
                )
            else:
                return APIResponse(1, '添加失败', results=book_ser.errors)
    
            
        """
        1)先确定要更新的对象 主键们 与 数据们
        2)通过校验数据库剔除 已删除的对象 与 不存在的对象
            主键们 => 剔除过程 => 可以修改的对象们
            数据们 => 剔除过程 => 可以修改的对象们对应的数据们
        3)反序列化及校验过程
            通过 => save() 完成更新
            失败 => ser_obj.errors 返回
        """
        # 单改群改
        def patch(self, request, *args, **kwargs):
            # 单改 /books/(pk)/  data  {"name": "new_name", ...}
            # 群改 /books/  data  [{"pk": 1, "name": "new_name", ...}, ...,{"pk": n, "name": "new_name", ...}]
            # 结果:
            # pks = [1, ..., n] => book_query => instance
            # data = [{"name": "new_name", ...}, ..., {"name": "new_name", ...}] => data
    
            # 数据预处理
            pk = kwargs.get('pk')
            request_data = request.data
            if pk:
                if not isinstance(request_data, dict):
                    return APIResponse(1, '单改数据有误')
                pks = [pk, ]
                data = [request_data, ]
            elif isinstance(request_data, list):
                try:
                    pks = []
                    for dic in request_data:
                        pks.append(dic.pop('pk'))
                    data = request_data
                except:
                    return APIResponse(1, '群改数据有误')
            else:
                return APIResponse(1, '数据格式有误')
    
            # 将 已删除的书籍 与 不存在的书籍 剔除 (提供修改的数据相对应也剔除)
            book_query = []
            filter_data = []
            for index, pk in enumerate(pks):
                book_obj = models.Book.objects.filter(is_delete=False, pk=pk).first()
                if book_obj:
                    book_query.append(book_obj)
                    filter_data.append(data[index])
            # 反序列化完成数据的修改
            book_ser = serializers.BookV3ModelSerializer(instance=book_query, data=filter_data, many=True, partial=True)
            if book_ser.is_valid():
                book_obj_list = book_ser.save()
                return APIResponse(1, 'ok',
                    results=serializers.BookV3ModelSerializer(book_obj_list, many=True).data
                )
            else:
                return APIResponse(1, '更新失败', results=book_ser.errors)
    
        # 单删群删  
        def delete(self, request, *args, **kwargs):
            # 单删 /books/(pk)/
            # 群删 /books/  数据包携带 pks => request.data
            pk = kwargs.get('pk')
            if pk:
                pks = [pk]
            else:
                pks = request.data.get('pks')
            if not pks:
                return APIResponse(1, '删除失败')
            book_query = models.Book.objects.filter(is_delete=False, pk__in=pks)
            if not book_query.update(is_delete=True):  # 操作的记录大于0就记录删除成功
                return APIResponse(1, '删除失败')
            return APIResponse(0, '删除成功')
            
    
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  • 原文地址:https://www.cnblogs.com/Dr-wei/p/11735529.html
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