Django Rest Framework Viewsets urls

Using Django Forms & APIs
1

Hi!

Per this code:

# views.py
EmployeeViewSet(GenericViewSet)

    @action(methods=["get"], detail=False)
    def approvedRequests(self, request, employee_id):
    	 # ...

LeaderViewSet(GenericViewSet)

    @action(methods=["get"], detail=False)
    def approvedRequests(self, request, employee_id):
        # ...

# urls.py
router.register(r'<int:employee_id>', views.EmployeeViewSet, basename="employee")
router.register(r'leaders/<int:employee_id>', views.LeaderViewSet, basename="leader")

urlpatters = [
    path('employees/', include(router.urls)),
    # ...
]

# Result
'^employees/{employee_id}/approvedRequests/$'
'^employees/leaders/{employee_id}/approvedRequests/$'

The urls matches what I need, and also Swagger let me provide an employee_id as a path parameter which is what I expect, but Django responds with a 404:

"GET /employees/4/approvedRequests/ HTTP/1.1" 404 7079

When reversing the url, it seems to me that the <int:employee_id> notation on the router it’s not working as if it were inside a path(), therefore the url with the path parameter doesn’t really exist.

>>> reverse("requests:request-leader-approvedRequests")
'/employees/leaders/%3Cint:employee_id%3E/approvedRequests/'

Other approach

Is there a way to “register” a viewset routes inside the path?

# urls.py

urlpatters = [
    path('employees/<int:employee_id>', EmployeeViewSet.urls), # Something like this 
]

I’m relatively new to DRF, so this may be a misconcept I have from routers.
Thanks in advance.

2

Hi Marco,

Before trying to manipulate the viewset into giving you the urls you want, you should try reworking the path argument to register. It looks like you’re supplying it a regular expression, r'<int:employee_id>', but the contents of that expression are what we’d typically supply to a django.urls.path call.

You need to treat that argument as if it were a re_path call instead.

1 Like
3

Thanks for answering Tim.

There is no example on the documentation of defining path parameters as an argument of router.register(), that was just me trying to solve my problem. :sweat_smile:

Is it common to define this kind of notation on routers?

That said, I made a simpler (and I think clever) approach: create a separate router for the second viewset.

Right now I can’t see a downside on this approach other than code duplication (3 lines).

4

Is it common to define this kind of notation on routers?

I would expect this to fall within range of normal use cases, but that’s based on my experiences.

That said, I made a simpler (and I think clever) approach: create a separate router for the second viewset.

Right now I can’t see a downside on this approach other than code duplication (3 lines).

That’s fair. It shouldn’t be necessary, but if it has unstuck you then move forward.

5

Now I’m intrigued about how to define path parameters as a router argument. Do you have any example repo?

6

I believe it should be the following.

router.register(r'^(?P<employee_id>\d+)/', views.EmployeeViewSet, basename="employee")
router.register(r'^leaders/(?P<employee_id>\d+)/', views.LeaderViewSet, basename="leader")
1 Like
7

Hi Marco,

Here is an example of a URL which will return an answer to a question. The models look a little like this.

class Quiz(models.model):
      id

class QuizQuestion(models.model):
      id
      quiz = models.ForeignKey(Quiz)

class QuizAnswer(models.model):
     id
     question = models.ForeignKey(QuizQuestion)

In order to list all questions or get a single question, I use this URL

router.register(
    "quiz/(?P<quiz>.+)/question/(?P<quiz_question>.+)/answers",
    QuizAnswerCreatorViewSet,
    basename="quiz_answer_viewset",
)

This means I can get all answers at:

/quiz/<quiz_id>/question/<question_id>/answers

and I can get a single answer with:

/quiz/<quiz_id>/question/<question_id>/answers/<answer_id>

In your ViewSet, you can define lookup_field = one_of_your_models_fields and use that field instead of the models primary key should you wish.

Hope that was helpful.

Cheers,

Conor

1 Like
8

I try to use regex as a last resort, but I know they can be pretty useful in certain cases.
Thanks for the tip! @CodenameTim @conor

1 Like
9

hi, happy to find you’re question , could you help me ?

i have this simple viewset and serializer

class UploadSerializer(serializers.ModelSerializer):
    class Meta:
        model = Account
        fields = ('image',)

class UploadViewSet(viewsets.ModelViewSet):
    queryset = Account.objects.all()
    serializer_class = UploadSerializer

i want to access the id that passed in the url , how could I ?

I tried a lot lot lot of solution but nothing help me… :smiling_face_with_tear: :sob:
sorry for my English ,

10

Hi!

Could you share the url pattern that maps with this viewset?
Also, is that all the code for the viewset?

Take in mind that ModelViewSet makes a lot of things for you under the hood.