自学教程：DRF过滤排序分页异常处理的过程记录

# 1、注册，在app中注册 settings.pyINSTALLED_APPS = [    'django_filters',]# 2、settings.py 配置REST_FRAMEWORK = {    'DEFAULT_FILTER_BACKENDS': (        'django_filters.rest_framework.DjangoFilterBackend',    )}# 3、在视图中添加filter_fields属性，指定过滤的字段class BooksView(ModelViewSet):    queryset = Books.objects.all()    serializer_class = BooksSerializer    filter_fields = ('title',) # 配置可以按照哪个字段来过滤    # http://127.0.0.1:8000/books/?title=红楼梦

# 1、首先视图中设置filter_backends=[OrderingFilter]# 2、然后再视图中添加 ordering_fields 属性，指定排序字段from rest_framework.filters import OrderingFilterclass BooksView(ModelViewSet):    queryset = Books.objects.all()    serializer_class = BooksSerializer    filter_backends = [OrderingFilter] # 第一步    ordering_fields = ['price','id'] # 第二步    # http://127.0.0.1:8000/books/?ordering=id 通过ordering查看有无指明排序的字段，并通过字段来排序# -id 表示针对id字段进行倒序排序# id  表示针对id字段进行升序排序

from rest_framework.generics import ListAPIViewfrom rest_framework.pagination import PageNumberPaginationfrom app01.models import Booksfrom app01.ser import BooksSerializer# 第一步：class BookPageNumberPagination(PageNumberPagination):    page_size = 3         # 每页条数    page_query_param = 'page'   # 查询第几页的key    page_size_query_param = 'size'  # 每一页显示的条数    max_page_size = 5   # 每页最大条数class BookView(ListAPIView):    queryset = Books.objects.all()    serializer_class = BooksSerializer        # 第二步：分页配置    pagination_class = BookPageNumberPagination        # url：http://127.0.0.1:8000/books/?page=1&size=5 查询第1页，一共显示五条数据

from rest_framework.generics import ListAPIViewfrom rest_framework.pagination import LimitOffsetPaginationfrom app01.models import Booksfrom app01.ser import BooksSerializer# 第一步：class BookLimitOffsetPagination(LimitOffsetPagination):    default_limit = 3           # 每页条数    limit_query_param = 'limit'     # 往后拿几条    offset_query_param = 'offset'   # 从第几条往后拿几条的标杆    max_limit = 5       # 每页最大拿几条class BookView(ListAPIView):    queryset = Books.objects.all()    serializer_class = BooksSerializer        # 第二步：分页配置    pagination_class = BookLimitOffsetPagination        # url：http://127.0.0.1:8000/books/?limit=3&offset=4  从第三条开始往后拿4条数据

from rest_framework.generics import ListAPIViewfrom rest_framework.pagination import CursorPaginationfrom app01.models import Booksfrom app01.ser import BooksSerializer# 第一步：class BookCursorPagination(CursorPagination):    cursor_query_param = 'cursor'   # 每页查询的key    page_size = 3       # 每页显示条数    ordering = 'id'    # 排序字段class BookView(ListAPIView):    queryset = Books.objects.all()    serializer_class = BooksSerializer        # 第二步：分页配置    pagination_class = BookCursorPagination        # url：http://127.0.0.1:8000/books/?cursor=cD0z

# 1、定义一个分页器class BookPageNumberPagination(PageNumberPagination):    page_size = 3         # 每页条数    page_query_param = 'page'   # 查询第几页的key    page_size_query_param = 'size'  # 每一页显示的条数    max_page_size = 5   # 每页最大条数class BookView(APIView):    def get(self, request, *args, **kwargs):        book_list = Books.objects.all()        # 2、实例化得到一个分页器对象        page_obj = BookPageNumberPagination()                # 3、调用paginate_queryset返回每一页的数据        book_list = page_obj.paginate_queryset(book_list, request, view=self)        # 4、获取上一页下一页链接        next_url = page_obj.get_next_link()        previous_url = page_obj.get_previous_link()        # 5、序列化        book_ser = BooksSerializer(book_list, many=True)                # 6、加入响应信息中        data = {'next_url': next_url, 'previous_url': previous_url, 'data': book_ser.data}        return Response(data=data)

def exception_handler(exc, context):    # 先判断是不是404    if isinstance(exc, Http404): # exc是异常信息的异常对象        exc = exceptions.NotFound()    # 然后判断是不是权限的问题    elif isinstance(exc, PermissionDenied):        exc = exceptions.PermissionDenied()  # 比如权限问题会返回一个字典         # 在判断你抛出的是不是API的异常——>认证权限这些都是继承了API的异常    if isinstance(exc, exceptions.APIException):        headers = {}        if getattr(exc, 'auth_header', None):            headers['WWW-Authenticate'] = exc.auth_header        if getattr(exc, 'wait', None):            headers['Retry-After'] = '%d' % exc.wait        if isinstance(exc.detail, (list, dict)):            data = exc.detail        else:            data = {'detail': exc.detail}        set_rollback()        return Response(data, status=exc.status_code, headers=headers)    # 只要是上面这些异常都做了处理       return None  # 意味有些异常它没有处理，就会交给Django自己处理

#  app01_auth.pyfrom rest_framework.views import exception_handlerfrom rest_framework.response import Responsedef app01_exception_handler(exc, context):    response = exception_handler(exc, context)  # 原来的drf处理的我们也需要    # 两种情况，一个是None，drf没有处理，Django处理了，但是处理的不符合需求    # response对象，drf处理了我们需要的    if not response:        # 如果没处理，那么我们自己处理        return Response(data={'status': 400, 'error': str(exc)}, status=400)    else:        # drf 处理了，那么取出它处理的信息，重新处理一下        return Response(data={'status': 400, 'error': response.data.get('detail')}, status=400)

REST_FRAMEWORK = {    'EXCEPTION_HANDLER': 'app01.app_auth.app01_exception_handler',}

class APIResponse(Response):    def __init__(self,code=100,msg='成功',data=None,status=None,headers=None,**kwargs):                dic = {'code': code, 'msg': msg}                if  data:            dic = {'code': code, 'msg': msg,'data':data}                    dic.update(kwargs)                super().__init__(data=dic, status=status,headers=headers)                # 使用return APIResponse(data={"name":'xiaoyang'},token='dsafsdfa',aa='dsafdsfdee')return APIResponse(data={"name":'xiaoyang'})return APIResponse(code='101',msg='错误',data={"name":'xiaoyang'},token='dsafsdfa',aa='dsafdsfdee',header={})