How to implement filter API in Django rest framewo

Question

I am trying to implement filter api in django rest. Something like -

localhost:8000/api/v1/users/?email=[e-mail]/

So it should search for user with the passed filter and return the result.But currently it is returning all user.

URLS.py

    url(r'^api/v1/users/$',   UserViews.UserList.as_view(), name='userlist_view'),
    url(r'^api/v1/users/(?P<email>.+)/$', UserViews.UserList.as_view(), name='userList_view'),
    url(r'^api/v1/users/(?P<pk>[0-9]+)/$', UserViews.UserDetail.as_view(), name='userdetail_view'),

UserViews.py

class UserList(generics.ListAPIView):
    """
    List all users, or create a new user.
    """
    lookup_url_kwarg = "email"

    def get(self, request, format=None):
        if request.user.is_authenticated():
            users = User.objects.all()
            serializer = UserSerializer(users, many=True)
            return Response(serializer.data)
        return Response("User is not authenticated.", status=status.HTTP_400_BAD_REQUEST)

    def post(self, request, format=None):

        valid_paylaod, msg = UserListRepository.validations_create_user(request.data)
        if not valid_paylaod:
            return Response(msg, status=status.HTTP_400_BAD_REQUEST)

        result = UserListRepository.create_user_repo(request)

        if not result.success:
            return Response(str(result.msg), status=result.status )

        return Response(UserSerializer(result.data).data, status=result.status)

   def get_queryset(self):
    # It restricts the userlist by retunning users having emails passed in uery param
    user = self.request.user
    if user.is_authenticated():
         if 'email' in self.request.query_params:
            email = self.request.query_params.get('email', None)
            users = User.objects.get(email= email)
            if not users:
                return Response( "User Not found", status=status.HTTP_404_NOT_FOUND)
            else:
                return Response(UserSerializer(User.objects.all()).data, status.HTTP_200_OK, users)
        else:
            return Response(UserSerializer().data, status=result.status)
    else:
        return Response("User is not authenticated.", status=status.HTTP_400_BAD_REQUEST)

Can some one tell why the request is not going to get_queryset() method and going to get() of UserList method. On removing get method, the request goes to get_queryset(self) method. On debugging, I found that I get valid Response before return statement -

(Pdb) UserSerializer(result.data).data
{'parent_id': 2, 'id': 31, 'group_id': '4', 'last_name': 'user',         'email': '[e-mail]', 'organization_id': 0, 'first_name':  'agency22'}

But Still in APi response, I get following error :

Internal Server Error: /api/v1/users/
 Traceback (most recent call last):
 File "/Users/richagupta/VirtualEnvs/py35/lib/python3.5/site-packages/django/core/handlers/base.py", line 149, in get_response
response = self.process_exception_by_middleware(e, request)
 File "/Users/richagupta/VirtualEnvs/py35/lib/python3.5/site-packages/django/core/handlers/base.py", line 147, in get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
Fi e "/Users/richagupta/VirtualEnvs/py35/lib/python3.5/site-packages/django/views/decorators/csrf.py", line 58, in wrapped_view
return view_func(*args, **kwargs)
File "/Users/richagupta/VirtualEnvs/py35/lib/python3.5/site-packages/django/views/generic/base.py", line 68, in view
return self.dispatch(request, *args, **kwargs)
 File "/Users/richagupta/VirtualEnvs/py35/lib/python3.5/site-packages/rest_framework/views.py", line 466, in dispatch
response = self.handle_exception(exc)
File "/Users/richagupta/VirtualEnvs/py35/lib/python3.5/site-packages/rest_framework/views.py", line 463, in dispatch
response = handler(request, *args, **kwargs)
File "/Users/richagupta/VirtualEnvs/py35/lib/python3.5/site-packages/rest_framework/generics.py", line 201, in get
return self.list(request, *args, **kwargs)
File "/Users/richagupta/VirtualEnvs/py35/lib/python3.5/site-packages/rest_framework/mixins.py", line 43, in list
if page is not None:
File "/Users/richagupta/VirtualEnvs/py35/lib/python3.5/site-packages/rest_framework/serializers.py", line 674, in data
ret = super(ListSerializer, self).data
File "/Users/richagupta/VirtualEnvs/py35/lib/python3.5/site-packages/rest_framework/serializers.py", line 239, in data
self._data = self.to_representation(self.instance)
File "/Users/richagupta/VirtualEnvs/py35/lib/python3.5/site-    packages/rest_framework/serializers.py", line 614, in to_representation
self.child.to_representation(item) for item in iterable
 File "/Users/richagupta/VirtualEnvs/py35/lib/python3.5/site-  packages/django/template/response.py", line 173, in __iter__
raise ContentNotRenderedError('The response content must be '
 django.template.response.ContentNotRenderedError: The response content          must be rendered before it can be iterated over.

I am not clear why . API URL I am hitting is : localhost:8000/api/v1/users?email=[e-mail]

Answer 1

In Django rest framework there is a proper specification of how to use filters. So your user class would look like.

class UserList(generics.ListAPIView):
    """
    List all users, or create a new user.
    """
    lookup_url_kwarg = "email"
    serializer_class = UserSerializer

    def get(self, request, format=None):
        if request.user.is_authenticated():
            users = User.objects.all()
            serializer = UserSerializer(users, many=True)
            return Response(serializer.data)
        return Response("User is not authenticated.", status=status.HTTP_400_BAD_REQUEST)

    def post(self, request, format=None):

        valid_paylaod, msg = UserListRepository.validations_create_user(request.data)
        if not valid_paylaod:
            return Response(msg, status=status.HTTP_400_BAD_REQUEST)

        result = UserListRepository.create_user_repo(request)

        if not result.success:
            return Response(str(result.msg), status=result.status )

        return Response(UserSerializer(result.data).data, status=result.status)

    def get_queryset(self):
        email = self.request.query_params.get('email', None)
        return User.objects.filter(email=email)

or you can try without get_queryset . The link would change , updated link is :

localhost:8000/api/v1/users/[e-mail]/

and the updated code is

class UserList(generics.ListCreateAPIView):
        """
        List all users, or create a new user.
        """
        lookup_url_kwarg = "email"
        serializer_class = UserSerializer

        def get(self, request, email,format=None):
            if request.user.is_authenticated():
                user_details = User.objects.filter(email=email)
                serializer = UserSerializer(user_details, many=True)
                return Response(serializer.data, status=status.status.HTTP_200_OK)
            return Response("User is not authenticated.", status=status.HTTP_400_BAD_REQUEST)

        def post(self, request, format=None):

            valid_paylaod, msg = UserListRepository.validations_create_user(request.data)
            if not valid_paylaod:
                return Response(msg, status=status.HTTP_400_BAD_REQUEST)

            result = UserListRepository.create_user_repo(request)

            if not result.success:
                return Response(str(result.msg), status=result.status )

            return Response(UserSerializer(result.data).data, status=result.status)

Answer 2

The problem is that you are overriding the get method of ListAPIView. This method is called by a GET request. The default implementation of get calls the list method of ListModelMixin and there get_queryset gets called:

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 Response(serializer.data)

If you override this method you have to call get_queryset yourself. If you just want to check if the user is authenticated and then call the default list method you can do it like this:

  def get(self, request, format=None):
        if request.user.is_authenticated():
            return super(UserList, self).get(request, format)
        return Response("User is not authenticated.", status=status.HTTP_400_BAD_REQUEST)

Answer 3

I'm confused by the UrlConf:

url(r'^api/v1/users/$', UserViews.UserList.as_view(), name='userlist_view'),
url(r'^api/v1/users/(?P<email>.+)/$', UserViews.UserList.as_view(), name='userList_view'),

• First one is for localhost:8000/api/v1/users/

• Second one is for localhost:8000/api/v1/users/[e-mail]/ not localhost:8000/api/v1/users/?email=[e-mail]/, this is a query parameter not kwargs, check this if you want to use query parameter

  class UserList(generics.ListAPIView):
  """
  List all users, or create a new user.
  """
  lookup_url_kwarg = "email"
  serializer_class = UserSerializer
  
  def post(self, request, format=None):
  
      valid_paylaod, msg = UserListRepository.validations_create_user(request.data)
      if not valid_paylaod:
          return Response(msg, status=status.HTTP_400_BAD_REQUEST)
  
      result = UserListRepository.create_user_repo(request)
  
      if not result.success:
          return Response(str(result.msg), status=result.status )
  
      return Response(UserSerializer(result.data).data, status=result.status)
  def get_queryset(self):
  """
  It restricts the userlist by return users having emails passed in query param
  """
      queryset = Users.objects.all()
      email = self.request.query_params.get('email', None)
      if email is not None:
          queryset = queryset.filter(email=email)
      return queryset
  

Answer 4

It looks like you are using Response from django instead of django-rest-framework.

You have to import Response from rest_framework.response

from rest_framework.response import Response