I have spent already a couple of days researching about this issue in similar questions and I am not able to get a solution. This should be something simple, I have a model:
model.py
class Item(models.Model):
"""Class to represent an item..."""
label = models.TextField(null=True)
name = models.TextField()
category = models.ForeignKey( "Category", on_delete=models.SET_NULL,
null=True, default=DEFAULT_CATEGORY_ID)
class Category(models.Model):
"""Class to represent the category of an Item. Like plants, bikes..."""
name = models.TextField()
description = models.TextField(null=True)
view.py
class ItemViewset(viewsets.ModelViewSet): # pylint: disable=too-many-ancestors
"""API Endpoint to return the list of items"""
queryset = Item.objects.all()
serializer_class = ItemSerializer
serializer.py
class ItemSerializer(serializers.ModelSerializer):
"""Serializer for Item."""
category = CategorySerializer(read_only=True)
class Meta: # pylint: disable=too-few-public-methods
"""Class to represent metadata of the object."""
model = Item
fields = [ 'id', 'label', 'name', 'category']
read_only_fields = ['id']
# def to_representation(self, instance):
# ret = super().to_representation(instance)
# ret['category'] = CategorySerializer(instance.category).data
# return ret
def create(self, request):
# Look up objects by arbitrary attributes.
# You can check here if your students are participating
# the classes and have taken the subjects they sign up for.
category = get_object_or_404(Category(), id=request.data.get('category'))
serializer = self.get_serializer(data=request.data)
serializer.is_valid(raise_exception=True)
serializer.save(category=category)
headers = self.get_success_headers(serializer.data)
return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)
If I have the line category = CategorySerializer(read_only=True) commented the nested get won't work, for example for a curl to an object. I will get just de id of the structure. If I uncomment it like it is in the example I get the right response:
{
"id": 60,
"label": null,
"name": "Delete me",
"category": {
"id": 1,
"name": "IT"
}
}
But then the post with id will not work, the category will be set to null.
How can I get both working at the same time?
Update: This is the post I want to do:
{
"label": "00000003",
"name": "Delete me",
"category": 1,
}
You can override the to_represention method of your serializer
class ItemSerializer(serializers.ModelSerializer):
"""Serializer for Item."""
class Meta: # pylint: disable=too-few-public-methods
"""Class to represent metadata of the object."""
model = Item
fields = [ 'id', 'label', 'name', 'category']
read_only_fields = ['id']
def to_representation(self, instance):
data = super().to_representation(instance)
data["category"] = CategorySerializer(instance.category).data
return data