DAY98

一、序列化组件之HyperlinkedIdentityField

HyperlinkedIdentityField可以通过反向解析向前台返回一个链接

url(r'^Books/(?P<id>d+)', views.BooksDetail.as_view(),name='test'),

# 传三个参数
# view_name='test':路由名字,用来反向解析
# lookup_field='publish_id':要反向解析的参数值
# lookup_url_kwarg='id':有名分组的名字
url = serializers.HyperlinkedIdentityField(view_name='test', lookup_field='publish_id',lookup_url_kwarg='id')

class Books(APIView):
    def get(self, request):
        response = {'status': 200, 'msg': '查询成功', 'data': None}
        books = models.Book.objects.all()
        # context={'request':request}是必写的
        ret = BooksSerializers(books, many=True,context={'request':request})
        response['data'] = ret.data
        return JsonResponse(response, safe=False)

# 返回结果
{
    "status": 200,
    "msg": "查询成功",
    "data": [
        {
            "id": 1,
            "url": "http://127.0.0.1:8000/Books/1",
            "name": "红楼梦",
            "price": "42.21",
            "publish": 1,
            "authors": [
                1,
                2
            ]
        },
        {
            "id": 3,
            "url": "http://127.0.0.1:8000/Books/2",
            "name": "西游记",
            "price": "12.32",
            "publish": 2,
            "authors": [
                2
            ]
        }
    ]
}
# url": "http://127.0.0.1:8000/Books/1"
# context={'request':request}：得到了域名http://127.0.0.1:8000
# view_name：得到了Books/(?P<id>d+)
# lookup_field 和lookup_url_kwarg：得到了1
# 把这三个拼接起来就成了一条路由http://127.0.0.1:8000/Books/1

二、序列化组件之数据校验

1.基本使用

class BooksSerializers(serializers.ModelSerializer):
    class Meta:
        model = models.Book
        fields = '__all__'

# 添加数据
def post(self, request):
    response = {'status': 200, 'msg': '添加成功', 'data': None}
    # 反序列化把request.data中的JSON格式的数据传入data中
    ret = BooksSerializers(data = request.data)
    # is_valid 对反序列化后的数据进行校验
    if ret.is_valid():
        # 对校验成功的数据保存
        ret.save()
        response['data'] = ret.data
    else:
        response['status'] = 201
        # errors：错误信息
        response['data'] = ret.errors
        response['msg'] = '添加失败'
     return JsonResponse(response, safe=False)

# 如果是更新数据
def put(self, request, id):
    response = {'status': 200, 'msg': '修改成功', 'data': None}
    books = models.Book.objects.filter(pk=id).first()
    if books:
        # 不传instance,调save(),往数据库新增数据
        # 传instance,调save(),修改数据
        # BooksSerializers(data=request.data.instance='要更新的对象')
        ret = BooksSerializers(data=request.data,instance=books)
        if ret.is_valid():
            ret.save()
            response['data'] = ret.data
        else:
            response['status'] = 201
            response['data'] = ret.errors
            response['msg'] = '修改失败'
    else:
        response['status'] = 201
        response['msg'] = '修改对象不存在'
    return JsonResponse(response, safe=False)

2.自定义错误信息

class BooksSerializers(serializers.ModelSerializer):
    class Meta:
        model = models.Book
        fields = '__all__'
	# 类似forms组件
    name = serializers.CharField(max_length=10, min_length=3, error_messages={'max_length': '最长为10','min_length': '最短为3','required':'不能为空'})

3.局部钩子以及全局钩子

# 局部钩子
# validate_字段名
def validate_name(self,value):
    if value.startswith('sb'):
        raise ValidationError('不能以sb开头')
    else:
        return value

# 全局钩子
# 只有通过字段校验才会判断全局钩子
def validate(self, value):
    # value是通过校验的数据
    print(value)
    name = value.get('name')
    price = value.get('price')
    if name and price:
        if str(name) == str(price):
            # 通过判断返回value
            return value
        else:
            # 没通过就报错
            raise ValidationError('名字跟价格不相等')
    return value

# 全局钩子error  
# non_field_errors:[错误信息]