Django Rest Framework: writable nested serializer - django

Question

I need to manage a JSON like this:
{
"name": "drink_type",
"description": "A type of drink",
"values": [
{
"value": "Coca-Cola",
"synonyms": [
"coca cola",
"coke"
]
},
{
"value": "Beer",
"synonyms": [
"beer"
]
}
]
}
models.py:
class Entity(models.Model):
name = models.CharField(max_length=50)
description = models.CharField(max_length=100)
created = models.DateTimeField(auto_now_add=True)
class Value(models.Model):
entity = models.ForeignKey(Entity, related_name='values', on_delete=models.CASCADE)
value = models.CharField(max_length=50)
created = models.DateTimeField(auto_now_add=True)
class Synonymous(models.Model):
value = models.ForeignKey(Value, related_name='synonyms', on_delete=models.CASCADE)
synonymous = models.CharField(max_length=50)
created = models.DateTimeField(auto_now_add=True)
serializers.py:
class ValueSerializer(serializers.ModelSerializer):
synonyms = serializers.SlugRelatedField(
many=True,
slug_field='synonymous',
queryset=Synonymous.objects.all()
)
class Meta:
model = Value
fields = ('value', 'synonyms')
def create(self, validated_data):
synonyms_data = validated_data.pop('synonyms')
value = Value.objects.create(**validated_data)
for synonyomous_data in synonyms_data:
Synonymous.objects.create(value=value, **synonyomous_data)
return value
class EntitySerializer(serializers.ModelSerializer):
values = ValueSerializer(many=True)
class Meta:
model = Entity
fields = ('id', 'name', 'description', 'values')
def create(self, validated_data):
values_data = validated_data.pop('values')
entity = Entity.objects.create(**validated_data)
for value_data in values_data:
# How can I call the create method of values?
pass
return entity
views.py
#api_view(['GET', 'POST'])
def entity_list(request, format=None):
"""
List all entities, or create a new entity.
"""
if request.method == 'GET':
entities = Entity.objects.all()
serializer = EntitySerializer(entities, many=True)
return Response(serializer.data)
elif request.method == 'POST':
serializer = EntitySerializer(data=request.data)
if serializer.is_valid():
serializer.save()
return Response(serializer.data, status=status.HTTP_201_CREATED)
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
The serializers works fine when the GET view is called, but when I try to create a new Entity using the POST view, I'm not able to call the create method of ValueSerializer Class and the data created is like this:
{
"name": "drink_type",
"description": "A type of drink",
"values": []
}
Someone can help me?
Thank you!

Answer 1

class SynonymousSerializer(serializers.ModelSerializer):
class Meta:
model = Synonymous
fields = '__all__'
class ValueSerializer(serializers.ModelSerializer):
entity = serializers.PrimaryKeyRelatedField(queryset = Entity.objects.all())
synonyms = ValueSerializer(many=True)
class Meta:
model = Value
fields = ('id', 'synonyms')
class EntitySerializer(serializers.ModelSerializer):
values = ValueSerializer(many=True)
class Meta:
model = Entity
fields = ('id','values')
q = Entity.objects.all()
serializer = EntitySerializer(q)
print serializer.data