CODEWITHSUNDEEP
pythondjangodjango-modelsdjango-rest-framework
Jon
Jon

Reputation: 432

Update Model Instance via Django REST POST

I've got a model "Assignment" that I want to be able to update through the api.

Updated per comments

urls.py

router = routers.DefaultRouter()
router.register(r'assignments', views.AssignmentList, base_name='Assignments')

urlpatterns = [
    url(r'^api/v1/', include(router.urls)),
    url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework')),
]

serializers.py

class AssignmentSerializer(serializers.ModelSerializer):
class Meta:
    model = Assignment
    fields = (
        'id', 'company', 'farm', 'sensor', 'name', 'location', 'notes', 'units', 'max_height', 'frequency',
        'interval', 'max_threshold', 'min_threshold', 'notify', 'last_alert_time', 'last_alert_water_level')

views.py

class AssignmentList(viewsets.ModelViewSet):
serializer_class = AssignmentSerializer
pagination_class = None

def get_queryset(self):
    queryset = Assignment.objects.all()
    company_id = self.request.query_params.get('company_id', None)
    sensor_id = self.request.query_params.get('sensor_id', None)
    if company_id is not None:
        queryset = Assignment.objects.filter(company_id=company_id)
    if sensor_id is not None:
        queryset = Assignment.objects.filter(sensor_id=sensor_id)
    return queryset

Currently my view allows for easy filtering based on two of the fields, 'company_id' and 'sensor_id'. This allows for easy access of the data in json. Unfortunately I can't figure out how to POST back even with the built in API form. I would like to be able to filter down to a single instance and edit a single field, let's say "assignment.name" for now.

It's my understanding that...

The actions provided by the ModelViewSet class are .list(), .retrieve(), .create(), .update(), .partial_update(), and .destroy(). (DRF Docs)

So what do I need to do to leverage them to edit a model instance via url? Or honestly just edit one period. I've been running in circles trying different Mixins, views (UpdateAPIView, RetrieveUpdateAPIView etc.) and this question in particular Stack Overflow: Django Rest Framework update field.

Upvotes: 1

Views: 1144

Answers (1)

Daniel Roseman
Daniel Roseman

Reputation: 600049

Why you're lacking the required foreign key fields is entirely the question.

The reason is that presumably your fields are called company, farm and sensor, not company_id etc. Because the underlying database fields are called company_id and so on, DRF detects them as read-only properties on the model and so allows you to specify those names in the fields tuple without showing an error, but doesn't display the field in the browsable API. Change the fields tuple to include the actual names of the Django fields.

Note also that since you're using HyperlinkedModelSerializer, DRF it expects a linked ViewSet for those related models. If you don't have those defined, chnage it to a basic ModelSerializer.

Upvotes: 1

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