Django Rest Framework read/write ModelSerializer with ChoiceField - django

Question

I have a few field in my model "OrderItem" that are ChoiceFields or Enums. I want to represent the label of the choice and doing it with serializers.CharField(source='get_service_display'). See also Django Rest Framework with ChoiceField.
That works fine, but creating objects is not working anymore with following error message OrderItem() got an unexpected keyword argument 'get_service_display'
Here is my model
class OrderItem(TimeStampedModel):
class Categories(models.IntegerChoices):
GRASS = (1, _('grass'))
order = models.ForeignKey(Order, related_name='order_items', on_delete=models.CASCADE)
unit_price = models.DecimalField(max_digits=6, decimal_places=2)
category = models.IntegerField(choices=Categories.choices)
and here my serializer
class OrderItemSerializer(serializers.ModelSerializer):
id = serializers.IntegerField(required=False)
category = serializers.CharField(source='get_category_display')
class Meta:
model = OrderItem
fields = ['id', 'unit_price', 'category']
read_only_fields = ['unit_price']
how can I create a model like this?

Answer 1

Try this:
from rest_framework import fields
from your_app_path.models import Categories
class OrderItemSerializer(serializers.ModelSerializer):
category = fields.ChoiceField(Categories.choices)
One other note. I'm not familiar with sub-classing models just for choices. I usually do it this way:
class OrderItem(TimeStampedModel):
GRASS = 'grass'
CATEGORY_CHOICES = (
(1, _(GRASS)),
)
order = models.ForeignKey(Order, related_name='order_items', on_delete=models.CASCADE)
unit_price = models.DecimalField(max_digits=6, decimal_places=2)
category = models.IntegerField(choices=CATEGORY_CHOICES)