How do I make this serializer display correctly? - django

Question

Django is giving me this error. The solution I've tried does not seem to work. It is asking me to make this an instance of Medication...Am I not already doing that? I'm trying to have two serializers cat and medication under the one careLogSerializer. Is that even possible? How can I best solve this error?
builtins.ValueError
ValueError: Cannot assign "OrderedDict([('name', 'carelog3'), ('duration', 'short'), ('frequency', '4')])": "CareLog.medication" must be a "Medication" instance.
Here is my serializer....
class CareLogSerializer(serializers.HyperlinkedModelSerializer):
cat = CatSerializer()
medication = MedicationSerializer()
# cat = CatSerializer(read_only=True) this allows put BUT TURNS OFF POST
class Meta:
model = CareLog
fields = (
'cat',
'slug',
'foster_manager',
'weight_unit_measure',
'weight_before_food',
'food_unit_measure',
'amount_of_food_taken',
'food_type',
'weight_after_food',
'stimulated',
'medication',
'medication_dosage_given',
'medication_dosage_unit',
'notes',
'created',
'photo',
)
extra_kwargs = {
'foster_manager': {
'read_only': True,
'required': False,
'lookup_field': 'id',
},
'medication': {
'read_only': True,
'required': False,
'lookup_field': 'slug',
},
'cat': {
'read_only': True,
'required': False,
'lookup_field': 'slug',
},
}
#staticmethod
def create(validated_data):
cat_data = validated_data.pop('cat')
cat_obj = Cat.objects.get(**cat_data)
return CareLog.objects.create(cat=cat_obj, **validated_data)
#staticmethod
def update(instance, validated_data):
instance.weight_unit_measure = validated_data['weight_unit_measure']
instance.weight_before_food = validated_data['weight_before_food']
instance.food_unit_measure = validated_data['food_unit_measure']
instance.amount_of_food_taken = validated_data['amount_of_food_taken']
instance.food_type = validated_data['food_type']
instance.weight_after_food = validated_data['weight_after_food']
instance.stimulated = validated_data['stimulated']
instance.stimulation_type = validated_data['stimulation_type']
instance.notes = validated_data['notes']
instance.save()
Here is my model
class CareLog(models.Model):
WEIGHT_MEASURE_CHOICES = (
('OZ', '(oz) Ounces'),
('LB', '(lb) Pounds'),
('G', '(G) Grams')
)
OUNCES = 'OZ'
POUNDS = 'LB'
GRAMS = 'G'
VOLUME_MEASURE_CHOICES = (
('ML', '(ml) Milliliters'),
('CC', '(cc) Cubic Centimeters'),
('OZ', '(oz) Ounces'),
('G', '(G) Grams')
)
MILLILITERS = 'ML'
CUBIC_CENTIMETERS = 'CC'
FOOD_TYPE_CHOICES = (
('MN', 'Mom (Nursing)'),
('BO', 'Bottle'),
('BS', 'Bottle / Syringe'),
('SG', 'Syringe Gruel'),
('GG', 'Syringe Gruel / Gruel'),
('G', 'Gruel')
)
BOTTLE = 'BO'
BOTTLE_SYRINGE = 'BS'
SYRINGE_GRUEL = 'SG'
SYRINGE_GRUEL_GRUEL = 'GG'
GRUEL = 'G'
STIMULATION_CHOICES = (
('UR', 'Urine'),
('FE', 'Feces'),
('UF', 'Urine / Feces'),
)
URINE = 'UR'
FECES = 'FE'
URINE_FECES = 'UF'
cat = models.ForeignKey(Cat)
slug = AutoSlugField(max_length=255, unique=True, blank=True, null=True)
foster_manager = models.ForeignKey(User, on_delete=models.CASCADE, blank=True, null=True)
weight_unit_measure = models.CharField(max_length=2, choices=WEIGHT_MEASURE_CHOICES, default=GRAMS)
weight_before_food = models.IntegerField(blank=True, null=True)
food_unit_measure = models.CharField(max_length=2, choices=WEIGHT_MEASURE_CHOICES, default=GRAMS)
amount_of_food_taken = models.IntegerField(blank=True, null=True)
food_type = models.CharField(max_length=2, choices=FOOD_TYPE_CHOICES, blank=True, null=True)
weight_after_food = models.IntegerField(blank=True, null=True)
stimulated = models.BooleanField(default=False)
stimulation_type = models.CharField(max_length=2, choices=STIMULATION_CHOICES, blank=True, null=True)
medication = models.ForeignKey(Medication, blank=True, null=True)
medication_dosage_given = models.FloatField(blank=True, null=True)
medication_dosage_unit = models.CharField(max_length=2, choices=VOLUME_MEASURE_CHOICES, blank=True, null=True,
help_text="If left blank this will default to "
"the default unit for the medication.")
notes = models.TextField(blank=True, null=True)
created = models.DateTimeField(auto_now_add=True)
photo = models.FileField(upload_to="kitty_photos", blank=True, null=True)
def save(self, *args, **kwargs):
# Update Cat's weight if 'Weight After Food' is updated
if self.weight_after_food:
self.cat.weight = self.weight_after_food
self.cat.save()
# Get all previous cat feedings
feedings = CareLog.objects.filter(cat=self.cat).order_by('-id')
if feedings:
# if the list of cat feedings contains the current, get rid of current from the list
if feedings[0] == self:
feedings = feedings[1:]
# TODO You broke it you fix it:
# If the feeding is a weight loss log it as the first/second/third
if self.weight_after_food < feedings[0].weight_after_food:
if self.cat.first_weight_loss:
self.cat.second_weight_loss = True
elif self.cat.second_weight_loss:
self.cat.third_weight_loss = True
elif self.cat.third_weight_loss:
self.cat.many_weight_losses = True
elif not self.cat.first_weight_loss:
self.cat.first_weight_loss = True
# Save Cat Object
self.cat.save()
if self.medication and not self.medication_dosage_unit:
self.medication_dosage_unit = self.medication.dosage_unit
super(CareLog, self).save(*args, **kwargs)
def __str__(self):
return "{cat}: {timestamp}".format(cat=self.cat.name, timestamp=self.created)

Answer 1

In your create method you need to do for medication same operation as for cat. Create object first and assign it to CareLog:
#staticmethod
def create(validated_data):
cat_data = validated_data.pop('cat')
cat_obj = Cat.objects.get(**cat_data)
med_data = validated_data.pop('medication')
med_obj = Medication.objects.create(**med_data)
return CareLog.objects.create(cat=cat_obj, medication=med_obj, **validated_data)
Otherwise Django trying to set as foreignkey's value dict object and raise the error.