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.py
INSTALLED_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 OrderingFilter
class 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 ListAPIView
from rest_framework.pagination import PageNumberPagination
from app01.models import Books
from 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 ListAPIView
from rest_framework.pagination import LimitOffsetPagination
from app01.models import Books
from 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 ListAPIView
from rest_framework.pagination import CursorPagination
from app01.models import Books
from 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.py
from rest_framework.views import exception_handler
from rest_framework.response import Response

def 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={})