#这个方法py文件我们可以写到任意地方，目的是在我们需要写一个Baseview的时候将放回方法引用

from django.utils import six
from rest_framework.response import Response
from rest_framework.serializers import Serializer

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

 def __init__(self, data=None, code=None, msg=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(Response, self).__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 = {"code": code, "message": msg, "data": data}
  self.template_name = template_name
  self.exception = exception
  self.content_type = content_type

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

#Base类，将增删改查方法重写
#!/usr/bin/env python
# -*- coding:utf-8 -*-

from assets import serializers
from assets import models
from rest_framework.response import Response
from rest_framework import status
from rest_framework import viewsets
from rest_framework.decorators import action
from rest_framework.pagination import PageNumberPagination
from django.shortcuts import get_object_or_404
from common.utils.custom_response import JsonResponse
from rest_framework import filters
from django_filters import rest_framework
from django_filters.rest_framework import DjangoFilterBackend

class CustomViewBase(viewsets.ModelViewSet):
 # pagination_class = LargeResultsSetPagination
 # filter_class = ServerFilter
 queryset = ''
 serializer_class = ''
 permission_classes = ()
 filter_fields = ()
 search_fields = ()
 filter_backends = (rest_framework.DjangoFilterBackend, filters.SearchFilter, filters.OrderingFilter,)

 def create(self, request, *args, **kwargs):
  serializer = self.get_serializer(data=request.data)
  serializer.is_valid(raise_exception=True)
  self.perform_create(serializer)
  headers = self.get_success_headers(serializer.data)
  return JsonResponse(data=serializer.data,msg="success",code=201,status=status.HTTP_201_CREATED,headers=headers)

 def list(self, request, *args, **kwargs):
  queryset = self.filter_queryset(self.get_queryset())
  page = self.paginate_queryset(queryset)
  if page is not None:
   serializer = self.get_serializer(page, many=True)
   return self.get_paginated_response(serializer.data)

  serializer = self.get_serializer(queryset, many=True)
  return JsonResponse(data=serializer.data,code=200,msg="success",status=status.HTTP_200_OK)

 def retrieve(self, request, *args, **kwargs):
  instance = self.get_object()
  serializer = self.get_serializer(instance)
  return JsonResponse(data=serializer.data,code=200,msg="success",status=status.HTTP_200_OK)

 def update(self, request, *args, **kwargs):
  partial = kwargs.pop('partial', False)
  instance = self.get_object()
  serializer = self.get_serializer(instance, data=request.data, partial=partial)
  serializer.is_valid(raise_exception=True)
  self.perform_update(serializer)

  if getattr(instance, '_prefetched_objects_cache', None):
   # If 'prefetch_related' has been applied to a queryset, we need to
   # forcibly invalidate the prefetch cache on the instance.
   instance._prefetched_objects_cache = {}

  return JsonResponse(data=serializer.data,msg="success",code=200,status=status.HTTP_200_OK)

 def destroy(self, request, *args, **kwargs):
  instance = self.get_object()
  self.perform_destroy(instance)
  return JsonResponse(data=[],code=204,msg="delete resource success",status=status.HTTP_204_NO_CONTENT)

class BatchLoadView(CustomViewBase):
 queryset = models.Manufacturer.objects.all()
 serializer_class = serializers.ManufacturerSerializer

 def list(self, request, *args, **kwargs):
  return JsonResponse(code=200, data=[], msg="testings")

#定义异常返回的路径脚本位置

REST_FRAMEWORK = {
  'EXCEPTION_HANDLER': 'common.utils.custom_execption.custom_exception_handler',
}

#注意，脚本路径需要与settings.py 定义的一样

from rest_framework.views import exception_handler

def custom_exception_handler(exc, context):
  # Call REST framework's default exception handler first,
  # to get the standard error response.
  response = exception_handler(exc, context)

  # Now add the HTTP status code to the response.
  if response is not None:
    print(response.data)
    response.data.clear()
    response.data['code'] = response.status_code
    response.data['data'] = []

    if response.status_code == 404:
      try:
        response.data['message'] = response.data.pop('detail')
        response.data['message'] = "Not found"
      except KeyError:
        response.data['message'] = "Not found"

    if response.status_code == 400:
      response.data['message'] = 'Input error'

    elif response.status_code == 401:
      response.data['message'] = "Auth failed"

    elif response.status_code >= 500:
      response.data['message'] = "Internal service errors"

    elif response.status_code == 403:
      response.data['message'] = "Access denied"

    elif response.status_code == 405:
      response.data['message'] = 'Request method error'
  return response

#无需调用，报错的时候他自己会调用！！