Django API: Updating a list of dictionaries - django

Question

I am trying to pass a list of dictionaries through my django rest framework API, loop through them, update the associated records in the model, and ultimately return the serialized data to the front end.
I am receiving the following error when submitting the list of dictionaries:
HTTP 400 Bad Request
Allow: PUT, OPTIONS
Content-Type: application/json
Vary: Accept
[
{
"non_field_errors": [
"Expected a list of items but got type \"dict\"."
]
},
{
"non_field_errors": [
"Expected a list of items but got type \"dict\"."
]
}
]
Here is the JSON I'm passing through the django rest framework API template:
[
{
"id": "1",
"order": "5"
},
{
"id": "2",
"order": "3"
}
]
Here is a view of my model:
class Waitlist(models.Model):
first_name = models.CharField(max_length=50)
last_name = models.CharField(max_length=50, blank=True)
identification = models.CharField(max_length=50)
email = models.EmailField(max_length=100, validators=[], blank=True)
mobile_phone = PhoneNumberField(blank=True)
store_number = models.PositiveSmallIntegerField()
order = models.PositiveSmallIntegerField()
status = models.PositiveSmallIntegerField()
created = models.DateTimeField(auto_now_add=True)
def __str__(self):
return self.first_name + ' ' + self.last_name
Here is a stripped down view of my views.py:
from django.shortcuts import render, get_object_or_404
from rest_framework.response import Response
from rest_framework.decorators import api_view
from rest_framework import status
from .models import Waitlist
from .serializers import WaitlistOrderSerializer, WaitlistOrderListSerializer
#api_view(['PUT'])
def waitlistOrder(request):
waitlist_data = request.data
waitlist = []
for data in waitlist_data:
waitlist_id = data.get('id')
w = Waitlist.objects.get(id=waitlist_id)
waitlist.append(w)
serializer = WaitlistOrderListSerializer(
waitlist, data=waitlist_data, many=True)
if serializer.is_valid():
serializer.save()
return Response({'success': 'Waitlist order updated successfully'})
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
And, here is a stripped down view of my my serializers.py
class WaitlistOrderSerializer(serializers.Serializer):
id = serializers.IntegerField()
order = serializers.IntegerField()
def update(self, instance, validated_data):
instance.order = validated_data.get('order', instance.order)
instance.save()
return instance
class WaitlistOrderListSerializer(serializers.ListSerializer):
child = WaitlistOrderSerializer()
def update(self, instances, validated_data):
for instance, data in zip(instances, validated_data):
self.child.update(instance, data)
return instances
Thanks for any suggestions.

Answer 1

The error is at this line:
serializer = WaitlistOrderListSerializer(
waitlist, data=waitlist_data, many=True)
It should be:
serializer = WaitlistOrderListSerializer(waitlist)
But there is no need to create ListSerializer. When you pass many=True, this ListSerializer is automatically created and WaitlistOrderSerializer will be passed as a child. Similar to what you you are doing.
So you can do:
serializer = WaitlistOrderSerializer(waitlist, many=True)
and remove your listserializer entirely.