We Keep Coding

Call one serializer's update() method from another serilaizer's create() method

I have 2 serializers serializer_1 and serializer_2 which are both model serilizer i want to execute update method of serializer_1 from create method of serializer_2 how can i achieve that?
class serializer_1(serializers.ModelSerializer):
date = serializers.DateTimeField(required=False, allow_null=True)
ispublic = serializers.BooleanField(allow_null=False)
details_api_url = serializers.SerializerMethodField()
dispute_types = OtherSerializer(many=True, required=False, write_only=True)
nature_of_dispute_list = serializers.SerializerMethodField()
plaintiff = OtherSerializer(many=True, required=False, write_only=True)
defendant = OtherSerializer(many=True, required=False, write_only=True)
claims_rep = OtherSerializer(many=True, required=False, write_only=True)
class Meta:
model = Media
fields = "__all_"
def update(self, instance, validated_data):
date = validated_data.pop('close_out_date', None)
plaintiff_data = validated_data.pop('plaintiff', [])
defendant_data = validated_data.pop('defendant', [])
claims_rep_data = validated_data.pop('claims', [])
is_summary_public_previous = instance.is_summary_public
obj = super().update(instance, validated_data)
return obj
class serializer_2(serializers.ModelsSerializer):
class Meta:
model = Fedia
fields = "__all__"
def create(self, validated_data):
request = self.context['request']
**serilizer_1_data** = validated_data.pop('serialzer_1_data', None)
is_final = validated_data.get('is_final')
serializer_1_object = Media.objects.create(**serializer_1_data)
if is_final:
**Call Serializer_1 Update method**
I have access to date,plaintiff etc mentioned under serializer_1 in create method of serilizer_2 through serilizer_1_data

How to serialize ManyToManyField

I want to serialize ManyToManyField but at the same time, I am looking for something which updates the same using ModelViewSet. I am able to serialize it but when I am updating it I am not able to. I know I can make a separate API for that but due to some requirements, I need to stick to one endpoint. Here is my code
class ComponentSerializers(serializers.ModelSerializer):
class Meta:
model = coreModel.Component
fields = '__all__'
class MonitorSerializers(serializers.ModelSerializer):
device = ComponentSerializers(read_only=True, many=True)
class Meta:
model = models.Monitor
fields = '__all__'
read_only_fields = ('id', 'created_at', 'updated_at',)
and views.py is
class MonitorViewSet(viewsets.ModelViewSet):
authentication_classes = (authentication.TokenAuthentication,)
permission_classes = (permissions.IsAuthenticated,)
queryset = models.Monitor.objects.all()
filter_backends = (DjangoFilterBackend,OrderingFilter,SearchFilter)
filter_class = superFilter.MonitorFilters
serializer_class = serializers.MonitorSerializers

If you want update ManytoMany or Related objects
Override
def update(self, validated_data):
in MonitorSerializers
class MonitorSerializers(serializers.ModelSerializer):
device = ComponentSerializers(read_only=True, many=True)
device_ids = serializers.ListField(write_only=True,
child = serializers.IntegerField(min_value = 1))
....
def update(self, instance, validated_data):
# Remove component data and save in variable
iscomponentdataexists = 'device_ids' in validated_data
if iscomponentdataexists :
componentdata= validated_data.pop('device_ids')
instance = super().update(instance, validated_data) # Update Monitor Data
# looping through new device_ids list
if iscomponentdataexists :
for deviceid in componentdata:
try:
obj = coreModel.Component.objects.get(id=deviceid)
instance.devices.add(obj)
except coreModel.Component.DoesNotExist:
pass
instance.save()
return instance
Remove read_only=True from device

Return a response with a list of serializers Django REST Framework

I'm coding some backend software for a second-hand selling app using Django and DjangoRestFramework. Right now, I'm trying to send a Response object that contains a list of products, but I seem not to be able to return an actual list of products, as I'm getting an error saying
ListSerializer is not JSON serializable.
I've tried both using the serializer constructor like this:
ProductoSerializer(products, many=True)
And by creating a list of ProductoSerializer.data and then creating the Response object with that.
Here's the serializers that I'm using:
class UserSerializer(serializers.HyperlinkedModelSerializer):
ciudad = serializers.SerializerMethodField()
conectado = serializers.SerializerMethodField()
class Meta:
model = Usuario
fields = ('uid', 'nombre', 'ciudad', 'conectado')
def get_ciudad(self, obj):
geolocator = Nominatim(user_agent="bookalo")
location = geolocator.reverse(str(obj.latitud_registro) + ',' + str(obj.longitud_registro))
return location.raw['address']['city']
def get_conectado(self, obj):
ahora = timezone.now()
result = relativedelta(ahora, obj.ultima_conexion)
return result.days == 0 and result.hours == 0 and result.months == 0 and result.years == 0 and result.minutes < 5
class TagSerializer(serializers.HyperlinkedModelSerializer):
class Meta:
model = Tag
fields = ('nombre')
class MultimediaSerializer(serializers.HyperlinkedModelSerializer):
contenido_url = serializers.SerializerMethodField()
class Meta:
model = ContenidoMultimedia
fields = ('contenido_url', 'orden_en_producto')
def get_contenido_url(self, obj):
return obj.contenido.url
class MiniProductoSerializer(serializers.HyperlinkedModelSerializer):
contenido_multimedia = serializers.SerializerMethodField()
class Meta:
model = Producto
fields = ('nombre', 'precio', 'estado_venta', 'contenido_multimedia')
def get_contenido_multimedia(self, obj):
contenido = ContenidoMultimedia.objects.get(producto=obj.pk, orden_en_producto=0)
return MultimediaSerializer(contenido)
class ProductoSerializer(serializers.HyperlinkedModelSerializer):
vendido_por = UserSerializer(read_only=True)
tiene_tags = TagSerializer(many=True, read_only=True)
contenido_multimedia = serializers.SerializerMethodField()
valoracion_media_usuario = serializers.SerializerMethodField()
class Meta:
model = Producto
fields = ('nombre', 'precio', 'estado_producto', 'estado_venta', 'latitud', 'longitud', 'tipo_envio', 'descripcion', 'vendido_por', 'tiene_tags', 'num_likes', 'contenido_multimedia')
def get_contenido_multimedia(self, obj):
contenido = ContenidoMultimedia.objects.filter(producto=obj.pk).order_by('orden_en_producto')
return MultimediaSerializer(contenido, many=True)
def get_valoracion_media_usuario(self, obj):
return Usuario.objects.get(pk=obj.vendido_por).media_valoraciones
class ValidacionEstrellaSerializer(serializers.HyperlinkedModelSerializer):
usuario_que_valora = UserSerializer(read_only=True)
producto_asociado = serializers.SerializerMethodField()
class Meta:
model = ValidacionEstrella
fields = ('estrellas', 'comentario', 'timestamp', 'usuario_que_valora', 'producto_asociado')
def get_producto_asociado(self, obj):
producto = Producto.objects.get(pk=obj.producto)
return MiniProductoSerializer(producto)
class UserProfileSerializer(serializers.HyperlinkedModelSerializer):
usuario_valorado_estrella = serializers.SerializerMethodField()
productos_favoritos = serializers.SerializerMethodField()
class Meta:
model = Usuario
fields = ('uid', 'nombre', 'esta_baneado', 'usuario_valorado_estrella', 'producto_del_usuario')
def get_usuario_valorado_estrella(self, obj):
validaciones = ValidacionEstrella.objects.filter(usuario_valorado=obj.pk).order_by('-timestamp')
return ValidacionEstrellaSerializer(validaciones, many=True, read_only=True)
def get_productos_favoritos(self, obj):
favoritos = Producto.objects.filter(le_gusta_a__in=[obj.pk])
return ProductoSerializer(favoritos, many=True, read_only=True)
class ReportSerializer(serializers.HyperlinkedModelSerializer):
#usuario_reportado = serializers.SerializerMethodField()
usuario_reportado = UserSerializer(read_only=True)
class Meta:
model = Report
fields = ('usuario_reportado', 'causa')
And here's the views.py function that I'm trying to code:
#api_view(['POST'])
#permission_classes((permissions.AllowAny,))
def SearchProduct(request, format=None):
if request.method != 'POST':
return Response(status=status.HTTP_400_BAD_REQUEST)
preposiciones = ['a','ante','bajo','cabe','con','contra','de','desde','en','entre',
'hacia','hasta','para','por','segun','sin','so','sobre','tras']
try:
search = request.POST.get('busqueda')
except:
return Response(status=status.HTTP_404_NOT_FOUND)
products = Producto.objects.none()
for word in search.split():
if word not in preposiciones:
productos_palabra = Producto.objects.filter(nombre__contains=word)
products = products | productos_palabra
products.distinct()
product_list = []
for prod in products:
product_list.append(ProductoSerializer(prod).data)
return Response({'productos': product_list}, status=status.HTTP_200_OK)
I'm using a request object because I also have to server a WebPage, and not only a mobile app, with the same function (the webpage part is still not coded though).
It should return all the products that contain at least one of the words from the user's search, and it all should be structured based on the ProductoSerializer object, but for some reason, it's outputting that error and I'm not quite sure how to fix it.
Thanks in advance, and if you need any extra information which I've missed, please do ask for it... It's been a long day and I probably missed something.

Seems like when you use SerializerMethodField you return serializer instance but not it's data:
For instance:
contenido_multimedia = serializers.SerializerMethodField()
def get_contenido_multimedia(self, obj):
contenido = ContenidoMultimedia.objects.filter(producto=obj.pk).order_by('orden_en_producto')
return MultimediaSerializer(contenido, many=True).data # <-- here try to add .data
It should be changed for all SerializerMethodField methods.

Convert URL of an object to its database instance

I created an extra function in my View that receives a list with hyperlinked references to some ResourceGroup objects, but I don't know how to convert them to database instances
class ResourceViewSet(viewsets.ModelViewSet):
queryset = Resource.objects.all()
serializer_class = ResourceSerializer
#action(methods=['put'], detail=True)
def groups_append(self, request, pk=None):
instance = self.get_object()
groups = request.data.get("groups")
for resource_group in groups:
instance.groups.add(WHAT_HERE(resource_group))
instance.save()
return Response(self.get_serializer(instance, many=False).data)
This is the request:
PUT http://.../api/resources/1/groups_append/
with body:
{"groups": ["http://.../api/resource_groups/1/", ...]}
ResourceSerializer:
class ResourceSerializer(serializers.HyperlinkedModelSerializer):
class Meta:
model = Resource
fields = ('resource_id', 'object_id', 'type', 'system', 'path', 'groups', 'job_set')
def update(self, instance, validated_data):
instance.object_id = validated_data.get('object_id', instance.object_id)
instance.type = validated_data.get('type', instance.type)
instance.system = validated_data.get('system', instance.system)
instance.path = validated_data.get('path', instance.path)
instance.save()
return instance
ResourceGroupSerializer:
class ResourceGroupSerializer(serializers.HyperlinkedModelSerializer):
class Meta:
model = ResourceGroup
fields = ('resource_group_id', 'label', 'resource_set')
def update(self, instance, validated_data):
instance.label = validated_data.get('label', instance.label)
instance.save()
return instance

use HyperlinkedRelatedField for groups in ResourceSerializer or just create a new serializer for this action(the main idea is to get the data using a serializers not just directly from the request body) like this:
class ResourceSerializer(serializers.HyperlinkedModelSerializer):
groups = serializers.HyperlinkedRelatedField(
many=True,
read_only=True,
view_name='groups-detail' ## name of the groups detail url
)
class Meta:
model = Resource
....
then edit your action as below:
#action(methods=['put'], detail=True)
def groups_append(self, request, pk=None):
instance = self.get_object()
serializer = self.get_serializer(instance, data=request.data, partial=True)
serializer.is_valid(raise_exception=True)
### then get the groups from the validated data
groups = serializer.validated_data.get('groups', [])
....
....
References:
1- hyperlinkedrelatedfield

How to map foreign key when serializing POST data?

I'm trying to map a foreign key to POST data when creating a new object through a serializer. There are two foreign keys in the object, one is serializing perfectly, the other is creating an error.
Model:
class Event(models.Model):
owner = models.ForeignKey('auth.User', related_name='owner', blank=True)
date = models.DateField('eventdate')
time = models.TimeField('eventtime', default=now)
eventtype = models.ForeignKey(EventType, related_name='eventtype', blank=True)
# duration = models.DurationField()
location = models.CharField(max_length=200, blank=True)
attenders = models.ManyToManyField(User, related_name='attenders')
invited = models.ManyToManyField(User, related_name='invitedlist')
View:
class EventMixin(RetrieveUpdateDestroyAPIView, CreateAPIView):
serializer_class = EventSerializer
def get_queryset(self):
return Event.objects.all()
def partial_update(self, request, *args, **kwargs):
request['owner'] = request.user
sname = request['eventtype']
request['eventtype'] = EventType.objects.filter(sname=sname)
json_str = json.dumps(self.request.data)
data = json.loads(json_str)
try:
invited = list(data['toInvite'])
for i in invited:
for j in User.objects.filter(username=i):
invite = EventInvite(invited=j, sender=request.user, event=self.get_object())
invite.save()
self.get_object().invited.add()
except KeyError:
pass
return super(EventMixin, self).partial_update(request, *args, **kwargs)
def create(self, request, *args, **kwargs):
new = {}
new['owner'] = request.user.__dict__
new['date'] = request.data['date']
new['time'] = request.data['time']
new['location'] = request.data['location']
sname = request.data['eventtype']
new['eventtype'] = EventType.objects.get(sname=sname).__dict__
json_str = json.dumps(self.request.data)
data = json.loads(json_str)
serializer = EventMixinSerializer(data=new)
with open('/tmp/log.txt', 'w+') as f:
f.write(str(serializer.is_valid()))
f.write(str(serializer.validated_data))
f.close()
serializer.is_valid();
serializer.save()
try:
invited = list(data['toInvite'])
for i in invited:
for j in User.objects.filter(username=i):
invite = EventInvite(invited=j, sender=request.user, event=self.get_object())
invite.save()
self.get_object().invited.add()
except KeyError:
pass
Serializer:
class EventMixinSerializer(serializers.ModelSerializer):
owner = UserSerializer(read_only=True)
eventtype = EventTypeSerializer()
attenders = FriendsListingField(read_only=True)
invited = FriendsListingField(read_only=True)
class Meta:
model = Event
fields = ('owner', 'eventtype', 'date', 'time', 'location', 'id', 'attenders', 'invited')
def create(self, validated_data):
owner = validated_data.pop('owner')
owner = owner.instance
eventtype = validated_data.pop('eventtype')
eventtype = eventtype.instance
event = Event.objects.create(owner=owner, eventtype=eventtype, **validated_data)
event.save()
return event
Error when owner field present:
False
{'owner': OrderedDict([('username', ['A user with that username already exists.'])])}
Result when UserSerializer(read_only=True) (pretty much diabling it):
True
OrderedDict([('eventtype', OrderedDict([('lname', 'Swimming'), ('sname', 'SWM'), ('category', '1')])), ('date', datetime.date(2015, 12, 22)), ('$
(Notice the event type data in the result)
Thanks!

You need to remove the validators from UserSerializer.
Assuming UserSerializer is a User ModelSerializer it'll extract the unique constraint on the User.username from the Model and your validation will fail.
To work this around you'll need to remove the UniqueValidator by overriding the validators list for the username field of the UserSerializer