Django rest framework serializer - Serialize single model field multiple times - django

Question

I would like to serialize one related field multiple times in output json. The first should contain pk of related object, and the second representation should be hyperlink. Any fancy way how to do it? I know SerializerMethodField, but I find it non-elegant approach.
My models:
class Person(models.Model):
first_name = models.CharField()
...
class Order(models.Model):
title = models.CharField()
person = models.ForeignKey(Person, related_name='orders')
What I want:
Serialize my Order model like this:
{
"title": "Alice in wonderland",
"person": 1, # represents persons's primary key
"person_url": "/person-detail/1"
}
What I tried / My serializer:
class OrderSerializer(serializers.ModelSerializer):
person = serializers.IntegerField()
person_url = serializers.HyperlinkedRelatedField(
view_name='myapp:user-profile',
lookup_field='pk'
)
class Meta:
model = Order
fields = ['title', 'person', 'person_url']
read_only_fields = ('__all__',)
But it this case Django was logically bitching about missing person_url field in database. How to proceed?

Answer 1

Your approach is pretty close. Couple of notes:
you don't need to specify the person integer field if you want the pk, you get that for free (ModelSerializer will automatically create a PrimaryKeyRelatedField called person)
you don't have to specify the fields here. DRF gives you the automatically generated ones plus explicitly defined fields on the serializer
lookup_field defaults to pk
assuming that your view name is correct (I can't see your urls), all you're missing from your HyperlinkRelatedField is a source attribute
Putting it together, something like this should work:
class OrderSerializer(serializers.ModelSerializer):
person_url = serializers.HyperlinkedRelatedField(
view_name='myapp:user-profile',
source='person',
read_only=True
)
class Meta:
model = Order
fields='__all__'
read_only_fields = ('__all__',)
NOTE: for my urls.py, I have a view name that looks more like person-detail.