Get every m2m relation in model as different object in DRF serializer - django

Question

I have a model Jurisdiction that has M2M relation with Franchise. And I use ModelViewSet on Jurisdiction.
models.py
class Franchise(models.Model):
name = models.CharField('Name', max_length=255, db_index=True)
class Jurisdiction(models.Model):
franchise = models.ManyToManyField(
Franchise,
verbose_name='Franchise',
related_name='jurisdictions',
blank=True
)
name = models.CharField(
"Jurisdiction name",
max_length=255,
db_index=True,
unique=True,
)
phone_number = models.CharField(
"Phone number",
max_length=12,
validators=[phone_number_regex],
unique=True,
)
My views.py
class JurisdictionViewSet(viewsets.ModelViewSet):
queryset = Jurisdiction.objects.all().prefetch_related('franchise')
serializer_class = JurisdictionSerializer
serializers.py
class JurisdictionSerializer(serializers.ModelSerializer):
franchise = FranchiseSerializer(many=True)
class Meta:
model = Jurisdiction
fields = (
'id', 'name', 'phone_number', 'franchise',
)
And serializer shows me:
{
"id": 1,
"name": "Test juris 1",
"phone_number": "200-000-1233",
"franchise": [
{
"id": 1,
"name": "Test franchise 1",
},
{
"id": 2,
"name": "Test franchise 2",
}
}
How I can get a list view of every m2m relation as a different object in serializer? I tried to change the to_representation method of serializer but nothing works
expected output:
[
{
"id": 1,
"name": "Test juris 1",
"phone_number": "200-000-1233",
"franchise_name": "Test franchise 1"
},
{
"id": 1,
"name": "Test juris 1",
"phone_number": "200-000-1233",
"franchise_name": "Test franchise 2"
}
]

Answer 1

You can customize the ListSerializer of your ModelSerializer. Specifically the to_representation method. For example:
from rest_framework import serializers
class CustomJurisdictionListSerializer(serializers.ListSerializer):
def to_representation(self, data):
iterable = data.all() if isinstance(data, models.Manager) else data
response = []
for item in iterable:
item_representation = self.child.to_representation(item)
for franchise in item.franchise.all():
representation = item_representation.copy()
representation['franchise_name'] = franchise.name
response.append(representation)
return response
Then remove franchise from JurisdictionSerializer and set the custom list serializer:
class JurisdictionSerializer(serializers.ModelSerializer):
class Meta:
model = Jurisdiction
fields = (
'id', 'name', 'phone_number',
)
list_serializer_class = CustomJurisdictionListSerializer