I want to add a dispatch method to some resource so I could use a wrapper decorator on it.
The issue is that it only works on the CRUD operations and wont go into the dispatch method on 'original' endpoints:
class SomeResource(SomeBaseResource):
class Meta(...): ...
def get_something_extra(self, request, **kwargs):
...
def patch_detail(self, request, **kwargs):
...
and the base resource:
class SomeBaseResource(ModelResource):
class Meta(...): ...
# the wrapper
#decorator_to_wrap_all_methods_with(...)
def dispatch(self, request_type, request, **kwargs):
logger.info('Enter')
response = super(SomeBaseResource, self).dispatch(request_type, request, **kwargs)
logger.info('Exit')
return response
So when I use patch request it is working as expected, but wont on calling the get_something_extra api.
How do I wrap ALL methods in resource?
A workaround solution is to add Middleware:
MIDDLEWARE = (
'my.basic.BaseMiddleware',
...
)
class BaseMiddleware(object):
def __init__(self, get_response):
self.get_response = get_response
#decorator_to_wrap_all_methods_with(...)
def __call__(self, request):
response = self.get_response(request)
return response
Related
I am trying to create test class for my custom middleware. The project is using Django REST framework. Middleware class works fine when server is running, but when I run test it behaves not quite as I would expect it to do. Maybe I misunderstood something, as I am quite new to testing in Django.
my_middleware.py:
class FX:
a = False
b = None
c = ''
def __init__(self) -> None:
pass
def __str__(self):
return 'fx ok'
class MyMiddleware(object):
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
request.fx = FX()
response = self.get_response(request)
print('done')
return response
views.py:
class TestView(APIView):
def get(self, request, format=None):
print('View ok')
print('FX: ', request.fx)
return Response({'result':'ok'})
tests.py:
class TestMyMiddleware(APITestCase):
#classmethod
def setUpTestData(cls):
pass
def setUp(self):
pass
def test_fx(self):
response = self.client.get(reverse('TestView'), content_type="application/json")
request = response.request
self.assertTrue(hasattr(request, 'fx'))
The code above actually runs the middleware. It prints "done" form the middleware call, then prints 'View ok' and also prints FX instance. However request.fx is not available in the test_fx method, thus giving assertion failure:
self.assertTrue(hasattr(request, 'fx'))
AssertionError: False is not true
Any idea what I might be doing wrong?
You need to access the request object from the response with response.wsgi_request instead of response.request.
class TestMyMiddleware(APITestCase):
#classmethod
def setUpTestData(cls):
pass
def setUp(self):
pass
def test_fx(self):
response = self.client.get(reverse('TestView'), content_type="application/json")
request = response.wsgi_request
self.assertTrue(hasattr(request, 'fx'))
I have a mixin which beside other things simplifies call of request.user object.
class MyMixin(LoginRequiredMixin, View):
...
leader = False
employee = False
def dispatch(self, request, *args, **kwargs):
self.leader = request.user.is_leader()
self.employee = request.user.is_employee()
return super().dispatch(request, *args, **kwargs)
...
And I have a heir of DetailView which has it's own dispatch method.
class MyDetailView(MyMixin, DetailView):
def dispatch(self, request, *args, **kwargs):
if not self.leader:
raise PermissionDenied
return super().dispatch(request, *args, **kwargs)
But as you could've told it ain't working. Is there a way to elegantly call parent dispatch method from it's heir?
You could make your attributes into properties so that the order of execution does not matter. Using cached_property will mean that the property is only evaluated once for each request
from django.utils.functional import cached_property
class MyMixin(LoginRequiredMixin, View):
#cached_property
def leader(self):
return self.request.user.is_leader()
#cached_property
def employee(self):
return self.request.user.is_employee()
I have RetrieveUpdateDestroyAPIView view like this.
class TaskRetrieveUpdateDestroyAPIView(RetrieveUpdateDestroyAPIView):
lookup_field = 'id'
serializer_class = TasksSerializer
def get_queryset(self):
query_set=Task.objects.get(id=self.kwargs['id'])
def get(self, request, *args, **kwargs):
return self.retrieve(request, *args, **kwargs)
def put(self, request, *args, **kwargs):
return self.update(request, *args, **kwargs)
def patch(self, request, *args, **kwargs):
return self.partial_update(request, *args, **kwargs)
def delete(self, request, *args, **kwargs):
return self.destroy(request, *args, **kwargs)
and my urls like this
path('task_detail/<int:id>', TaskRetrieveUpdateDestroyAPIView.as_view(), name="get_task"),
I am trying to PUT , PATCH , GET but getting same error
{
"detail": "Not found.",
"status_code": 404
}
The issue is in the function get_queryset, It expects a queryset but yours returns a single object, that's what the get function does as described here. So, you need to either set the queryset class field or use the get_queryset function.
You don't need to look up the task object yourself, that's what the generic view does for you. also you don't have to specify the method handlers(get, post, i.e.) yourself, they are already generated because you use RetrieveUpdateDestroyAPIView class. Also, since the lookup field defaults to the primary key(id), so, you could omit that, too
Try this code
class TaskRetrieveUpdateDestroyAPIView(RetrieveUpdateDestroyAPIView):
queryset = Task.objects.all()
serializer_class = TasksSerializer
and use pk instead of id
path('task_detail/<int:pk>', TaskRetrieveUpdateDestroyAPIView.as_view(), name="get_task")
or you could leave the lookup field as id and use it in the path function. It's pretty much the same thing, just saving some code
I noticed that I am setting site-wide context variables and request variables for many views on my site. Naturally, this situation calls for inheritance. If all of my view class-based views are inheriting from SiteView instead of the generic View, I can factor out all the commonalities into the SiteView child class. I can then inherit from SiteView on all my views. But, I cannot get this to work. Here is my code:
from django.contrib.auth.decorators import login_required
from django.views.generic import View
from django.utils.decorators import method_decorator
class SiteView(View):
''' Extends the generic django-supplied View class '''
#method_decorator(login_required)
def dispatch(self, request, *args, **kwargs):
return super(SiteView, self).dispatch(*args, **kwargs)
def get(self, *args, **kwargs):
''' Adds the variables required in the get request '''
context = super(SiteView, self).get(*args, **kwargs)
context['common_var'] = 'some common value'
context['user'] = request.user
return self.render_to_response(context)
This throws the following TypeError:
dispatch() missing 1 required positional argument: 'request'
Any help would be appreciated
Edit: Even though the correct answer is marked, there were other issues with the code. In particular, the get method of the SiteView should not have the following line:
context = super(SiteView, self).get(*args, **kwargs)
This is because the View class does NOT have any get method.
You forgot to pass the request to the super().dispatch(..) call:
class SiteView(View):
#method_decorator(login_required)
def dispatch(self, request, *args, **kwargs):
return super(SiteView, self).dispatch(request, *args, **kwargs)
or you can just omit the request in the dispatch parameters, and thus pass it through *args and **kwargs:
class SiteView(View):
#method_decorator(login_required)
def dispatch(self, *args, **kwargs):
return super(SiteView, self).dispatch(*args, **kwargs)
It is however probably more elegant, to pass the name of the function, like:
#method_decorator(login_required, name='dispatch')
class SiteView(View):
# ...
EDIT: Note that a View has no get(..), post(..), etc. method. The dispatch(..) method will look if such method exists, and if so redirect to it. If such method does not exists, it will return a "405 Method Not Allowed" response.
Your get(..) function thus be implemented like:
#method_decorator(login_required, name='dispatch')
class SiteView(View):
''' Extends the generic django-supplied View class '''
def render_to_response(self, context):
# ...
def get(self, request, *args, **kwargs):
context = {
'common_var': 'some common value',
'user': request.user
}
return self.render_to_response(context)
It perhaps makes more sense to implement a "mixin" (perhaps with a subclass of the LoginRequiredMixin mixin [Django-doc].
For example like:
class SiteViewMixin(LoginRequiredMixin):
def get_context_data(self, *args, **kwargs):
context = super().get_context_data(*args, **kwargs)
context.update(common_var='some common value', user=self.request.user)
return context
and then use the mixin in another view, like:
class SomeView(SiteViewMixin, TemplateView):
# ...
How would one create "new style" middleware, which fulfills an equivalent implementation to using the process_request() hook with the "old style"?
I've already adapted pre 1.10 middleware process_request() using MiddlewareMixin...
from django.utils.deprecation import MiddlewareMixin
class MyCustomMiddleware(MiddlewareMixin):
def process_request(self, request):
# My request logic
return response
I'd like to know how to do a "pure" >1.9 "new style" implementation. I tried doing so by implementing __init__() and __call__() like this without luck:
class MyCustomMiddleware(object):
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
# My request logic
return response
Thanks.
Here an example...
class TimeStampMiddleware(object):
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
request.timestamp = datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S')
response = self.get_response(request)
return response
Now you can get the timestamp in every request from yours views! (is only an example)