响应模块Response

Response类生成对象需要的参数，以及Response类的对象可以使用的属性
1、参数：Response(data=响应的数据, status=响应的网络状态码, headers=想通过响应头再携带部分信息给前端)
2、属性：response.data response.status_code response.status_text

核心：知道response对象产生可以传那些信息，response对象又是如何访问这些信息的

"""
返回数据类型
response = {
    'status': 7,
    'exc': '异常信息'
}
"""
from rest_framework.response import Response
from rest_framework.views import exception_handler as drf_exception_handler
from rest_framework import status
def exception_handler(exc, context):
    response = drf_exception_handler(exc, context)

    if response is None: # drf没有处理的异常(服务器异常)
        return Response(status=status.HTTP_500_INTERNAL_SERVER_ERROR, data={
            'status': 7,
            'exc': '%s' % exc
        })
#设置状态码
    # 项目阶段，要记录到日志文件
    return Response(status=response.status_code, data={
        'status': 7,
        # drf处理的客户端异常，原始处理方式是将异常信息放在response对象的data中，data的格式是{'datail': '具体的异常信息'}
        'exc': '%s' % response.data.get('detail')
    })

作用

根据用户请求URL 或用户可接受的类型，筛选出合适的渲染组件。
用户请求URL：
http://127.0.0.1:8000/test/?format=json
http://127.0.0.1:8000/test.json

内置渲染器

显示json格式：JSONRenderer

访问URL：

默认显示格式：BrowsableAPIRenderer（可以修改它的html文件）

访问URL：

表格方式：AdminRenderer

访问URL：

form表单方式：HTMLFormRenderer

访问URL：

局部使用

from rest_framework.renderers import  HTMLFormRenderer,BrowsableAPIRenderer
class BookDetailView(APIView):
    renderer_classes = [HTMLFormRenderer,BrowsableAPIRenderer ]
    def get(self,request,pk):
        book_obj=models.Book.objects.filter(pk=pk).first()
        bs=BookSerializers(book_obj,many=False)
        return Response(bs.data)
    def put(self,request,pk):
        book_obj = models.Book.objects.filter(pk=pk).first()

        bs=BookSerializers(data=request.data,instance=book_obj)
        if bs.is_valid():
            bs.save() # update
            return Response(bs.data)
        else:
            return Response(bs.errors)
    def delete(self,request,pk):
        models.Book.objects.filter(pk=pk).delete()

        return Response("")

全局使用

settings.py中配置

REST_FRAMEWORK = {
    'DEFAULT_RENDERER_CLASSES': ['rest_framework.renderers.JSONRenderer']
}

自定义显示模块

from rest_framework.renderers import  TemplateHTMLRenderer
class BookDetailView(APIView):
    renderer_classes = [TemplateHTMLRenderer]
    def get(self,request,pk):
        book_obj=models.Book.objects.filter(pk=pk).first()
        bs=BookSerializers(book_obj,many=False)
        return Response(bs.data,template_name='aa.html')
<!DOCTYPE html>
<html lang="en">
<head>
    
    <title>Title</title>
</head>
<body>
{{ title }}
{{ publishDate }}
</body>
</html>

源码分析

Response类的__init__方法

class Response(SimpleTemplateResponse):
    """
    An HttpResponse that allows its data to be rendered into
    arbitrary media types.
    """

    def __init__(self, data=None, status=None,
                 template_name=None, headers=None,
                 exception=False, content_type=None):
        """
        Alters the init arguments slightly.
        For example, drop 'template_name', and instead use 'data'.

        Setting 'renderer' and 'media_type' will typically be deferred,
        For example being set automatically by the `APIView`.
        """
        super().__init__(None, status=status)

        if isinstance(data, Serializer):
            msg = (
                'You passed a Serializer instance as data, but '
                'probably meant to pass serialized `.data` or '
                '`.error`. representation.'
            )
            raise AssertionError(msg)

        self.data = data
        self.template_name = template_name
        self.exception = exception
        self.content_type = content_type

        if headers:
            for name, value in headers.items():
                self[name] = value

响应模块格式化response(二次封装)

返回信息

格式：

{
	'status':0,
	'msg':"",
	'results':'',
	...
}

from rest_framework.response import Response

class APIResponse(Response):
    # 格式化data
    def __init__(self, status=0, msg='ok', results=None, http_status=None, headers=None, exception=False, **kwargs):
        data = {  # json的response基础有数据状态码和数据状态信息
            'status': status,
            'msg': msg
        }
        if results is not None:  # 后台有数据，响应数据
            data['results'] = results
        data.update(**kwargs)  # 后台的一切自定义响应数据直接放到响应数据data中
        super().__init__(data=data, status=http_status, headers=headers, exception=exception)