How to solve django.url.exceptions.NoReverseMatch with kwargs? - django-rest-framework

Question

I am trying to update an object that has already been created.
Following is my urls.py:
from django.conf.urls import url
from django.urls import include, path
from rest_framework import routers
from . import admin_views, temp_views, views
app_name = "transactions"
router = routers.SimpleRouter()
router.register(r"transactions", views.TransactionViewSet)
router.register(r"offerings", views.OfferingViewSet)
router.register(r"bank_accounts", views.BankAccountViewSet)
router.register(r"merchants", views.MerchantViewSet)
Following is my views.py:
class MerchantViewSet(GetPrefixedIDMixin, viewsets.ModelViewSet):
"""POST support for /merchants/."""
print ("in MerchantViewSet")
queryset = models.Merchant.objects.all()
serializer_class = serializers.CreateMerchantSerializer
lookup_field = "id"
lookup_value_regex = f"{models.Merchant.id_prefix}_[a-f0-9]{32}"
permission_classes = [permissions.MerchantPermission]
def get_queryset(self):
"""Filter the queryset based on the full merchant name or starting with a letter."""
queryset = models.Merchant.objects.all()
search_param = self.request.query_params.get("search", None)
if search_param:
if search_param.startswith("^"):
queryset = queryset.filter(name__istartswith=search_param[1:])
else:
queryset = queryset.filter(name__icontains=search_param)
return queryset
Following is the test I am trying to write:
class MerchantsViewSetTest(tests.BigETestCase): # noqa
#classmethod
def setUpClass(cls): # noqa
super(MerchantsViewSetTest, cls).setUpClass()
cls.application = tests.get_application()
tests.create_group("merchant")
cls.consumer_user = tests.create_consumer()
cls.admin = tests.create_administrator()
cls.merchant_geraldine = models.Merchant.objects.create(
name="Test Account 1",
contact_name="Geraldine Groves",
contact_email="geraldine#example.com",
contact_phone_number="[phone]",
)
cls. merchant_barbara = models.Merchant.objects.create(
name="Account 2",
contact_name="Barbara",
contact_email="barbara#example.com",
contact_phone_number="[phone]",
)
def test_edit_merchant(self): # noqa
# url = reverse("bige_transactions:merchant-list", kwargs={"id": self.merchant_geraldine.prefixed_id},)
url = reverse("bige_transactions:merchant-list", kwargs={"id": self.merchant_geraldine.prefixed_id})
# payload
data = {"name": "Edited"}
# verify anonymous cannot edit a user
self.put(url, data, status_code=401)
Following is my permissions.py:
class MerchantPermission(BasePermission): # noqa
def _has_get_permission(self, request, view): # noqa
access_token = get_access_token(request)
# we allow the request if the user is an admin
if is_administrator(access_token.user):
return True
return False
def _has_put_permission(self, request, view): # noqa
print ("entered put permissions")
access_token = get_access_token(request)
# we allow the request if the user is an admin
if is_administrator(access_token.user):
print ("Admin detected!")
return True
return False
def has_permission(self, request, view): # noqa
# is it a supported method
method = request.method.lower()
if method in view.http_method_names:
if method == "post":
return True
elif method == "get":
return self._has_get_permission(request, view)
elif method == "put":
return self._has_put_permission(request, view)
# always deny by default
raise exceptions.MethodNotAllowed(request.method)
So basically what I am trying to do is to add a functionality whereby I can update a merchant's detail. From my understanding from reading the Django Rest Framework documentation, the router.register method in my urls.py should set up all the URL's for create, list, update, retrieve and destroy. With my current test method, I get :
django.urls.exceptions.NoReverseMatch: Reverse for 'merchant-list' with keyword arguments '{'id': 'merch_b6c983ec082b4c7eb321b335fe9b122c'}' not found. 1 pattern(s) tried: ['merchants/$']
I am able to create, list and search users (didn't add those methods here as they are not relevant and don't want to make this question longer than it needs to be). I changing the url to
url = reverse("bige_transactions:merchant-list") + "?id=" + self.merchant_geraldine.prefixed_id
which does print out the URL, and I do not get the reverse() method error anymore, but I get a 404 error. So I am kind of stuck trying to implement this and I cannot find any examples on how to use the update() method that is built in ModelViewSet other than mentions of that it can be used.

Answer 1

When you register your viewset using router.register(r"merchants", views.MerchantViewSet) behind the scene you will get two different reverse urls:
merchants-list -> actual url will be ^merchants/$
merchants-detail -> actual url will be ^merchants/<pk>/$
In your case since you defined lookup_field="id" if might be <id> instead of <pk>. So your code needs to use the detail url like this:
url = reverse("bige_transactions:merchant-detail", kwargs={'id': self.merchant_geraldine.prefixed_id})
For more info check related docs