django select only specific fields from many to many field in serializer - django

Question

My models:
class RequisiteItem(models.Model):
id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
enrollable = models.ForeignKey(Enrollable, on_delete=models.CASCADE)
created_by = models.ForeignKey(ElsUser, on_delete=models.CASCADE)
completed_within_days = models.IntegerField()
date_completed_by = models.DateTimeField(default=now, editable=False)
class Requisite(models.Model):
id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
name = models.CharField(default=None, blank=True, null=True, max_length=255)
description = models.CharField(default=None, blank=True, null=True, max_length=255)
items = models.ManyToManyField(RequisiteItem, blank=True)
enrolments = models.ManyToManyField(Enrollee, blank=True)
created_by = models.ForeignKey(ElsUser, on_delete=models.CASCADE, related_name="requisites", default=None)
timestamp = models.DateTimeField(default=now, editable=False)
#property
def created_by_user(self):
return self.created_by.username
Serializer class:
class RequisiteSerializer(serializers.ModelSerializer):
created_by = serializers.CharField(source='created_by_user')
class Meta:
model = Requisite
fields = ('id', 'name', 'description', 'items', 'enrolments', 'created_by', 'timestamp')
read_only_fields = ['id']
depth = 1
I have enrolments ,created by,requisite items which are foreign keys and manytomany fields etc .In my list API i want only specific fileds from the foreign key to be displayed. For example in the created by field, Elsuser is a custom user inheriting from AbstractUser . I want only the username and email fields from this model and not the entire fields. Similar case for the manyto many fields . How do i implement this?

Answer 1

You can create a serializer to get only the required fields. Example:
class UserSerializer(serializers.ModelSerializer):
class Meta:
model = User
fields = ('') #the fields you require to display
Then change your serializer as:
class RequisiteSerializer(serializers.ModelSerializer):
created_by = UserSerializer()
class Meta:
model = Requisite
fields = ('id', 'name', 'description', 'items', 'enrolments', 'created_by', 'timestamp')
read_only_fields = ['id']
depth = 1