How to return a standard Django Rest Framework JSON from an enum? - django

Question

I'm not very familiar with DRF and I haven't found a solution on google for this problem (most answers are about a model with a field as enum, my problem is different)
You see, we have an Enum in a Django application. Let's call it SomeValuesEnum.
class SomeValuesEnum(Enum):
ONE_VALUE = "One value"
ANOTHER_VALUE = "Another value"
What I need to do is to create a GET endpoint that returns the following
{
"count": 2,
"page_count": 1,
"next": null,
"previous": null,
"results": [
{
"value": "One value",
"name": "ONE_VALUE"
}, {
"value": "Another value",
"name": "ANOTHER_VALUE"
}
]
}
I know I need to create a serializer, but I haven't been able to create one and "feed it".
For example, I started with something like this:
class SomeValueSerializer(serializers.Serializer):
Meta:
model = SomeValuesEnum,
fields = '__all__'
and on the view:
class SomeValueListView(APIView):
serializer_class = SomeValueSerializer
def get(self, request):
choices = [{"value": target.value, "name": target.value.capitalize()} for target in SomeValuesEnum]
serializer = SomeValueSerializer(data=choices)
return Response(status=status.HTTP_200_OK, data=serializer.data)
I also tried this
class IncidentSerializer(serializers.Serializer):
name = serializers.CharField(required=False, allow_blank=True, max_length=100)
value = serializers.CharField(required=False, allow_blank=True, max_length=100)
I'm not sure if I'm failing on the creation of the serializer, or in how I invoke him on the view (or maybe both)
Any guidance on the right direction will be greatly appreciate it.

Answer 1

An enum is not a django model. You can have a DRF serializer for something that isn't a model, but you shouldn't give it a model field of something that isn't a model.
See here: Declaring Serializers
Not here: Model Serializers
Furthermore, you are creating a class-based view here:
SomeValueListView(APIView)
You don't necessarily need this, you could use a function based view, which may be easier for you to understand given you are new to DRF. I only say function based views are easier to understand since there isn't so much built in functionality. This can make it easier to debug for someone new to DRF. You can still use the serializer by calling it directly in the view.
See here: Function Based Views
And here: Serializing Objects
Finally...given this code:
choices = [{"value": target.value, "name": target.value.capitalize()} for target in SomeValuesEnum]
I am making the assumption that there could be multiple distinct objects going into this serializer, given that you are using a list comprehension. Either you need to call the serializer separately for each object in the array, or you call the serializer with (many=True). Pretty sure this is your main issue. Like this:
serializer = SomeValueSerializer(data=choices, many=True)
See here: Dealing with multiple objects
Also, in my experience it is better to parse incoming data to the serializer within the serializer itself, not in the view. To me it is a separation of concerns issue, but other people may feel differently. This would look something like this:
class SomeValueListView(APIView):
serializer_class = SomeValueSerializer
def get(self, request):
serializer = SomeValueSerializer(data=SomeValuesEnum)
return Response(status=status.HTTP_200_OK, data=serializer.data)
class SomeValueSerializer(serializer.Serializer):
def to_internal_value(self, data)
name = data.value.capitalize()
value = data.value
return {
'name': name,
'value': value,
}