Creating a Nested Serializer with two "Sibling" Models - django

Question

I'm attempting to get a JSON output similar to this:
{
name: John Doe,
best_buy_price: 420,
best_sell_price: 69,
player_profile: {
tsn_link: https://a_link.com
}
playerlistingadvanced: { # This is where I'm having the issue
sales_minute: 7,
}
}
I have three models. playerProfile being the "main" model and playerListing and playerListingAdvanced are connected to playerProfile via a one-to-one relationship. playerPfofile will have its own endpoint, but I'd also like to create an endpoint that is primarily the listings and advanced listing data (as seen above).
Here is a stripped down version of the model.py file:
class PlayerProfile(models.Model):
card_id = models.CharField(max_length=120, unique=True, primary_key=True)
name = models.CharField(max_length=420, null=True)
tsn_link = models.CharField(max_length=420, null=True)
class PlayerListing(models.Model):
player_profile = models.OneToOneField(
PlayerProfile,
on_delete=models.CASCADE,
null=True)
name = models.CharField(max_length=420, null=True)
best_sell_price = models.IntegerField(null=True)
best_buy_price = models.IntegerField(null=True)
class PlayerListingAdvanced(models.Model):
player_profile = models.OneToOneField(
PlayerProfile,
on_delete=models.CASCADE,
null=True)
sales_minute = models.DecimalField(max_digits=1000, decimal_places=2, null=True)
Here is the serializer.py I have tried, but haven't gotten to work.
class PlayerListingAdvancedForNestingSerializer(serializers.ModelSerializer):
class Meta:
model = PlayerListingAdvanced
fields = (
'sales_minute',
'last_week_average_buy',
'last_week_average_sell',
)
class PlayerListingSerializer(serializers.ModelSerializer):
player_profile = PlayerProfileForListingSerializer() # works
playerlistingadvanced = PlayerListingAdvancedForNestingSerializer() #doesn't work
class Meta:
model = PlayerListing
fields = (
'name',
'best_sell_price',
'best_buy_price',
'playerlistingadvanced',
'player_profile'
)
I'm assuming because playerListing and playerListingAdvanced are not directly related, that I'll need to do something else to make this work. Can someone point me in the right direction?

Answer 1

You can use SerializerMethodField. Your assuming is correct. Try this:
class PlayerListingSerializer(serializers.ModelSerializer):
player_profile = PlayerProfileForListingSerializer()
playerlistingadvanced = serializers.SerializerMethodField()
class Meta:
model = PlayerListing
fields = (
'name',
'best_sell_price',
'best_buy_price',
'playerlistingadvanced',
'player_profile'
)
def get_playerlistingadvanced(self, obj: PlayerListing):
player_profile = obj.player_profile
if hasattr(player_profile, 'playerlistingadvanced'):
serializer = PlayerListingAdvancedForNestingSerializer(instance=player_profile.playerlistingadvanced)
return serializer.data
return None