Serialize foreign key object that is AbstractUser - django

Question

I am serializing a model using the Django REST framework successfully, but would like to add a field from a related model. I have seen other posts describe how to do this using nested serializers, however mine is different because the other model I am trying to access is an AbstractUser class.
I would like to serialize the UserDefinedEquipName field from CustomUser.
models (some fields removed for clarity):
accounts/models.py
from django.contrib.auth.models import AbstractUser
class CustomUser(AbstractUser):
UserDefinedEquipName = models.CharField(max_length=50, default = "Default equip",)
....
builds/models.py
from accounts.models import CustomUser
from django.contrib.auth import get_user_model
class Build(models.Model):
author = models.ForeignKey(get_user_model(),on_delete=models.CASCADE,)
machineName = models.OneToOneField(max_length=50,blank=True,)
....
So my thought is to pass the value into the serializer but can't seem to figure out how to access the value without getting error AttributeError: type object 'Build' has no attribute 'CustomUser'
I have tried:
My serializers.py:
from rest_framework import serializers
from .models import Data, Build, CustomUser
from django.contrib.auth.models import AbstractUser
class buildStatsAPI_serializer(serializers.ModelSerializer):
equipName = Build.CustomUser.UserDefinedEquipName
#also tried:
#equipName = Build.CustomUser__set.all()
class Meta:
fields = ('id','author','machineName','equipName',)
model = Build
Am I missing something small here? Or is there a much better way of doing this. It seems like if this wasn't an AbstractUser class it would be much easier.
EDIT - Added views.py
class buildStatsAPI(generics.ListCreateAPIView):#for build stats JSON
permission_classes = (permissions.IsAuthenticated,)
serializer_class = buildStatsAPI_serializer
def get_queryset(self):
machinesOwned =CustomUser.objects.filter(customerTag=self.request.user.customerTag).filter(isDevice=True)
machineList = []
for machine in machinesOwned:
machineList = machineList + [machine.id]
query = Build.objects.filter(deleted=0, author_id__in=machineList,).values().order_by('pk')
return query

Answer 1

I think you are defining the Serializer improperly. You can't directly reference Model in a serializer. You need to use any kind of fields. For example, if you use SerializerMethodField, you can try like this:
class buildStatsAPI_serializer(serializers.ModelSerializer):
equipName = serializers.SerializerMethodField()
class Meta:
fields = ('id','author','machineName','equipName',)
model = Build
def get_equipName(self, obj):
# here obj is a build model object
return obj.author.UserDefinedEquipName
Update
Please update your get_queryset method so that it returns a queryset like this(I have refactored it a bit):
def get_queryset(self):
query = Build.objects.filter(deleted=0, author__customerTag=self.request.user.customerTag, author__isDevice=True) # removed .values() because it will return a dictionary
return query