Heyo! First of all: thanks for releasing and supporting this, really appreciate it!

class CategorySerializer(serializers.ModelSerializer):
    # We need special recursive serialization here for Category (parent) -> Category (child) relationship
    children = serializers.ListSerializer(read_only=True, child=RecursiveField())
    alternate_namings = CategoryOfficeNamingSerializer(many=True, required=False)

    class Meta:
        model = Category
        fields = (
            'id',
            'children',
            'parent',
            'order',
            'name',
            'alternate_namings',
        )

Using this Serializer with django-rest-swagger I get this error:

AttributeError: 'RecursiveField' object has no attribute 'get_fields'

Not sure if maybe I'm misusing RecursiveField? Thanks for any advice!

It would be nice if the field honoured the Meta.depth attribute. This would help avoid issues with circular relationships as well as keep payloads lighter.

More documentation on depth can be found here http://www.django-rest-framework.org/api-guide/serializers/#specifying-nested-serialization

By default, the ModelSerializer uses PrimaryKeyFields so maybe that can be the fallback when depth is reached. That, or perhaps specify what field type to fallback.

Hi ! Thanks for this great plugin for django rest framework. Is there any way to specify the depth of the recursion ? I tried using the class Meta depth attribute but I don't think the field uses it. What would be the best approach to this ? Best regards,

Hi,

I am using this package to get all children of any node. Here is my Model and Serializer :

class VenueSerializer(serializers.HyperlinkedModelSerializer):
    children = RecursiveField(source='children.all', many=True, read_only=True)

    class Meta:
        model = Venue
        fields = ( 'name', 'description','children',)

class Venue(MPTTModel):
    name = models.CharField(_('name'), max_length=100)
    description = models.TextField(_('description'), null=True, blank=True)
    parent = TreeForeignKey('self', null=True, blank=True, related_name='children',
        db_index=True, verbose_name=_('parent'))

But I am getting children list NULL

{
  "count": 1,
  "next": null,
  "previous": null,
  "results": [
    {
      "name": "first Venue",
      "description": "testing purpose",
      "children": [
        {},
        {}
      ]
    }
  ]
}

Any idea where I am getting things wrong

Model:

class Category(models.Model):
    title = models.CharField(max_length=50, verbose_name=_('Title'), db_index=True)
    parent = models.ForeignKey('self', related_name="children", null=True, blank=True)

Seralizer:

class CategorySerializer(serializers.ModelSerializer):
    children = serializers.ListField(child=RecursiveField())

    class Meta:
        model = Category
        fields = ('id', 'title', 'children')  

It is does not work (it should?) with TypeError: 'RelatedManager' object is not iterable .

Hm, seems it is DRF issue, because

children = serializers.ListField() 

does not work too.

only this is work, returned ids only.

class CategorySerializer(serializers.ModelSerializer):

    class Meta:
        model = Category
        fields = ('id', 'title', 'children')  

Can you held with this, or close issue...

Thank you for your work on this plug-in.

I hope this thread is still monitored.

I am having an issue that I think is due to a non-defaulted primary key. I am creating a Django stack for an existing MSSQL database, and have successfully integrated my database models with DRF. However, due to the nature of the existing database, I am stuck using pre-determined field names, including primary key assignments.

Model:

from django.db import models, connection

class ClientModel(models.Model):
    ClientID = models.IntegerField(primary_key=True)
    Name = models.CharField(max_length=100)
    BusinessUnitID = models.IntegerField(default=0)
    ParentID = models.ForeignKey('self', blank=True, null=True, on_delete=models.CASCADE)
    InvoicePreFix = models.CharField(max_length=50, default="")
    BillingTerms = models.IntegerField(default=0)
    BillingInterval = models.IntegerField(default=0)
    MaximumAllowedExposure = models.DecimalField(decimal_places=2, max_digits=10, default=0)
    InvoiceTypeID = models.IntegerField(default=0)

    @staticmethod
    def getClientList():
        cur = connection.cursor()
        cur.execute("{CALL getClientList}")
        results = cur.fetchall()
        cur.close()
        return [ClientModel(*row) for row in results]

Serializer:

class ClientModelSerializer(serializers.ModelSerializer):
    ParentID = RecursiveField(allow_null=True)

    class Meta:
        model = ClientModel
        fields = (
            'ClientID',
            'Name',
            'BusinessUnitID',
            'ParentID',
            'InvoicePreFix',
            'BillingTerms',
            'BillingInterval',
            'MaximumAllowedExposure',
            'InvoiceTypeID'
        )

After installation and implementation of DRF-Recursive, I am receiving the following error:

('42S22', "[42S22] [Microsoft][SQL Server Native Client 11.0][SQL Server]Invalid column name 'Name'. (207) (SQLExecDirectW);_ [42S22] [Microsoft][SQL Server Native Client 11.0][SQL Server]Invalid column name 'BusinessUnitID'. (207); [42S22] [Microsoft][SQL Server Native Client 11.0][SQL Server]Invalid column name 'ParentID_id'. (207); [42S22] [Microsoft][SQL Server Native Client 11.0][SQL Server]Invalid column name 'InvoicePreFix'. (207); [42S22] [Microsoft][SQL Server Native Client 11.0][SQL Server]Invalid column name 'BillingTerms'. (207); [42S22] [Microsoft][SQL Server Native Client 11.0][SQL Server]Invalid column name 'BillingInterval'. (207); [42S22] [Microsoft][SQL Server Native Client 11.0][SQL Server]Invalid column name 'MaximumAllowedExposure'. (207); [42S22] [Microsoft][SQL Server Native Client 11.0][SQL Server]Invalid column name 'InvoiceTypeID'. (207); [42S22] [Microsoft][SQL Server Native Client 11.0][SQL Server]Statement(s) could not be prepared. (8180)")

Of note, as shown in the error, my primary key field ("ClientID") is not included in the error report. I could not find an example on the Git page that did not use Django's "id" default primary key field.

Also, my "ParentID" field is getting an "_id" appended to the end of the field name. How can I allow this field name to remain the same?
[Microsoft][SQL Server Native Client 11.0][SQL Server]Invalid column name 'ParentID_id'. (207);

Thank you for your time and effort.

models.py

from django.db import models
from mptt.models import MPTTModel, TreeForeignKey

from poinkbackend.apps.menus.models import Menu


class Category(MPTTModel):
    name = models.CharField(max_length=50)
    parent = TreeForeignKey('self', null=True, blank=True, related_name='children', db_index=True)
    menu = models.ForeignKey(Menu, related_name='categories', related_query_name='categories',
                             on_delete=models.SET_NULL, null=True, blank=True)

    class MPTTMeta:
        order_insertion_by = ['name']

    def __str__(self):
        return f'{self.name} {self.menu}'

Serializers.py

from rest_framework import serializers
from rest_framework_recursive.fields import RecursiveField

from poinkbackend.apps.categories.models import Category


class CategorySerializer(serializers.ModelSerializer):
    parent = RecursiveField(allow_null=True)

    class Meta:
        model = Category
        fields = [
            'id',
            'name',
            'parent',
            'menu',
        ]

viewsets.py

from rest_framework import viewsets

from poinkbackend.apps.categories.api.serializers import CategorySerializer
from poinkbackend.apps.categories.models import Category


class CategoryViewSet(viewsets.ModelViewSet):
    queryset = Category.objects.all()
    serializer_class = CategorySerializer

I got the error maximum recursion depth exceeded

Where am I wrong?

django==1.11.9
djangorestframework-jwt==1.11.0
djangorestframework-recursive==0.1.2
djangorestframework==3.7.7
django-mptt==0.9.0

So I've followed your example use cases but I'm experiencing some issues. Here is the code I'm using:

class RequestSerial(ModelSerializer):

    bidpick = RecursiveField('BidSerial')


    class Meta:

        model = Request

        fields = '__all__'


class BidSerial(ModelSerializer):

    request = RequestSerial()


    class Meta:

        model = Bid

        fields = '__all__'

I definitely expected this to work but I'm getting a maximum recursion depth exceeded as a runtime error.

I have a set of fields specified, yet am getting others.

Serializer:

class ServiceSerializer(recursive_serializers.ModelSerializer):
    parent = RecursiveField(required=False)
    class Meta:
        model = Service
        fieds = ('id', 'name', 'parent', 'active')

Results:

    "results": [
        {
            "id": 18, 
            "parent": null, 
            "name": "Bankruptcy", 
            "active": true, 
            "lft": 1, 
            "rght": 2, 
            "tree_id": 2, 
            "level": 0
        }
    ]```

Hi all,

I am experiencing an issue when using the RecursiveField. I am creating questionnaires. To create sections in the questionnaire, you can recursively add questionnaire items to existing questionnaire items. The questionnaire is well created into the DB but when it is returning the response, there is no item key for the nested questionnaire items. Do you have an idea? (Thanks for your help)

django RF= 3.7.3 python=2.7.10

Those are my models:

class Questionnaire(models.Model):

	rowId = models.BigAutoField(primary_key=True, editable=False, db_column="rowId")
	
	id = models.UUIDField(unique=True, default=uuid4, editable=False, db_column="id")

	owner = models.ForeignKey('oauth.Application', related_name='Questionnaire', on_delete=models.CASCADE, db_column="ownerId")

	url = models.CharField(max_length=250, null=True, db_column="url")

	title = models.CharField(max_length=200, null=True, db_column="title")

	status = models.CharField(max_length=3, choices=STATUS_CHOICES, default=UNKNOWN, db_column="status")

	date = models.DateField(auto_now=True, null=False, db_column="date")

	publisher = models.CharField(max_length=200, null=True, db_column="publisher")

	description = models.CharField(max_length=400, null=True, db_column="description")

	purpose = models.CharField(max_length=400, null=True, db_column="purpose")

	# item
	# Reverse foreign key ---> QuestionnaireItem

	class Meta:
		db_table = "questionnaire"

class QuestionnaireItem(models.Model):

	id = models.BigAutoField(primary_key=True, editable=False, db_column="id")

	questionnaire = models.ForeignKey("api.Questionnaire",
										db_index=True,
                                                                                null=True,
										on_delete=models.PROTECT,
										to_field='id',
										related_name='item',
										db_column="questionnaireId")


	text = models.CharField(max_length=400, null=True, db_column="text")

	type = models.CharField(max_length=4, choices=TYPE_CHOICES, default=UNKNOWN, db_column="type")

	required = models.NullBooleanField(null=True, db_column="required")

	readOnly = models.NullBooleanField(null=True, db_column="readOnly")

	maxLength = models.PositiveIntegerField(null=True, db_column="maxLength")

	# option
	# Reverse foreign key ---> QuestionnaireOption

	initialBoolean = models.NullBooleanField(null=True, db_column="initialBoolean")

	initialDecimal = models.DecimalField(null=True, db_column="initialDecimal", max_digits=10, decimal_places=2)

	initialInteger = models.IntegerField(null=True, db_column="initialInteger")

	initialDate = models.DateField(null=True, db_column="initialDate")

	initialString = models.CharField(max_length=400, null=True, db_column="initialString")

	initialUri = models.CharField(max_length=200, null=True, db_column="initialUri")

	initialAttachment = models.OneToOneField("api.Attachment", null=True, on_delete=models.PROTECT, related_name="initialAttachment", db_column="initialAttachmentId")

	initialQuantity = models.OneToOneField("api.Quantity", null=True, on_delete=models.PROTECT, related_name="initialQuantity", db_column="initialQuantityId")

	# item
	# Allow to create sections and sub-sections
	# Reverse foreign key ---> QuestionnaireItem
	item = models.ForeignKey('self',
							 db_index=True,
							 on_delete=models.PROTECT,
							 null=True,
						     related_name='sub_item',
						     db_column="questionnaireItemId")

	class Meta:
		db_table = "questionnaire_item"

class QuestionnaireOption(models.Model):

	id = models.BigAutoField(primary_key=True, editable=False, db_column="id")

	questionnaireItem = models.ForeignKey("api.QuestionnaireItem",
										  db_index=True,
										  on_delete=models.PROTECT,
										  null=True,
										  to_field='id',
										  related_name='option',
										  db_column="questionnaireItemId")

	valueInteger = models.IntegerField(null=True, db_column="valueInteger")

	valueDate = models.DateField(null=True, db_column="valueDate")

	valueString = models.CharField(max_length=200, null=True, db_column="valueUri")

	class Meta:
		db_table = "questionnaire_option"

Those are my serializers:

class QuestionnaireOptionSerializer(serializers.ModelSerializer):

	valueInteger = serializers.IntegerField(required=False)

	valueDate = serializers.DateField(required=False)

	valueString = serializers.CharField(required=False)

	class Meta:
		model = QuestionnaireItem
		fields = ('valueInteger', 'valueDate', 'valueString')

	def to_representation(self, instance):
		result = super(QuestionnaireOptionSerializer, self).to_representation(instance)
		return OrderedDict([(key, result[key]) for key in result if result[key] is not None])


class QuestionnaireItemSerializer(serializers.ModelSerializer):

	text = serializers.CharField(required=True)

	type = CustomChoiceField(choices=TYPE_CHOICES, required=True)

	required = serializers.CharField(required=False)

	readOnly = serializers.CharField(required=False)

	maxLength = serializers.IntegerField(required=False)

	option = QuestionnaireOptionSerializer(many=True, required=False)

	initialBoolean = serializers.BooleanField(required=False)

	initialDecimal = serializers.DecimalField(required=False, max_digits=10, decimal_places=2)

	initialInteger = serializers.IntegerField(required=False)

	initialDate = serializers.DateField(required=False)

	initialString = serializers.CharField(required=False)

	initialUri = serializers.CharField(required=False)

	initialAttachment = AttachmentSerializer(many=False, required=False)

	initialQuantity = QuantitySerializer(many=False, required=False)

	item = serializers.ListField(child=RecursiveField(), required=False)

	class Meta:
		model = QuestionnaireItem
		managed = True
		fields = ('text', 'type', 'required', 'readOnly', 'maxLength', 'option', 'initialBoolean', 'initialDecimal', 'initialInteger', 'initialDate', 'initialString', 'initialUri', 'initialAttachment', 'initialQuantity', 'item')

	def to_representation(self, instance):
		result = super(QuestionnaireItemSerializer, self).to_representation(instance)
		return OrderedDict([(key, result[key]) for key in result if result[key] is not None])



class QuestionnaireSerializer(serializers.ModelSerializer):

	id = serializers.UUIDField(read_only=True)

	url = serializers.CharField(required=False)

	title = serializers.CharField(required=True)

	status = CustomChoiceField(choices=STATUS_CHOICES, required=False)

	date = serializers.DateField(required=False)

	publisher = serializers.CharField(required=False)

	description = serializers.CharField(required=False)

	purpose = serializers.CharField(required=False)

	item = QuestionnaireItemSerializer(many=True, required=True)

	def create(self, validated_data):

		print(validated_data)

		# Get the linked application
		application = get_app_by_access_token(self.context)

		# Dealing with the nested structure
		questionnaire_item_data = validated_data.pop('item')

		# Saving the questionnaire
		questionnaire = Questionnaire.objects.create(owner=application, **validated_data)

		# Saving first level
		for item in questionnaire_item_data:

			should_add_option = False
			should_add_item = False

			if 'option' in item:
				questionnaire_option_data = item.pop('option')
				should_add_option = True

			if 'item' in item:
				sub_item_data = item.pop('item')
				should_add_item = True

			# Saving the questionnaire item
			questionnaireItem = QuestionnaireItem.objects.create(questionnaire=questionnaire, **item)

			if should_add_option:
				# Saving second level
				for option in questionnaire_option_data:
					# Saving the questionnaire options
					QuestionnaireOption.objects.create(questionnaireItem=questionnaireItem, **option)

			if should_add_item:
				# Saving second level
				for sub_item in sub_item_data:
					# Saving the questionnaire sub item
					QuestionnaireItem.objects.create(questionnaire=questionnaire, item=questionnaireItem, **sub_item)

		# Return
		return questionnaire

	class Meta:
		model = Questionnaire
		fields = ('id', 'url', 'title', 'status', 'date', 'publisher', 'description', 'purpose', 'item')

	def to_representation(self, instance):
		result = super(QuestionnaireSerializer, self).to_representation(instance)
		return OrderedDict([(key, result[key]) for key in result if result[key] is not None])

I am trying to follow the docs https://github.com/heywbj/django-rest-framework-recursive/blob/master/tests/test_recursive.py

Python 3.6.2 django==1.11.4 djangorestframework-recursive==0.1.2 djangorestframework==3.6.3

models

from django.db import models
from mptt.fields import TreeForeignKey
from mptt.models import MPTTModel


class ProductCategory(MPTTModel):
    name = models.CharField(max_length=255, blank=False, unique=True)
    description = models.TextField(blank=True, null=True)

    parent = TreeForeignKey('self', null=True, blank=True, related_name='children', db_index=True)

    class MPTTMeta:
        order_insertion_by = ['name']

    class Meta:
        verbose_name_plural = u"Categories"

    def __str__(self):
        return f"{self.name}"

serializers

from rest_framework import serializers
from rest_framework_recursive.fields import RecursiveField

from apps.categories.models import ProductCategory


class CategoryTreeSerializer(serializers.Serializer):
    parent = RecursiveField(allow_null=True)

    class Meta:
        model = ProductCategory
        fields = ['name', 'description', 'parent']

views

from rest_framework import viewsets

from apps.categories.api.serializers import CategoryTreeSerializer
from apps.categories.models import ProductCategory


class ProductCategoryViewSet(viewsets.ModelViewSet):
    queryset = ProductCategory.objects.all()
    serializer_class = CategoryTreeSerializer

api_urls

from rest_framework import routers

from apps.categories.api.views import ProductCategoryViewSet

router = routers.SimpleRouter()
router.register(r'product-category', ProductCategoryViewSet, base_name='product-catagory')

urlpatterns = [
    # url(r'^forgot-password/$', ForgotPasswordFormView.as_view()),
]

urlpatterns += router.urls

I got the error

  builtins.RecursionError
RecursionError: maximum recursion depth exceeded

Where am I wrong? In the traceback does not show my lines. It shows only library lines.

DJango 4.1 djangorestframework==3.14.0

models.py

class Category(PreModel):
    name = models.CharField(max_length=255)
    slug = models.SlugField(blank=True)
    image = models.ImageField(null=True, blank=True)
    parent = models.ForeignKey('self', related_name='get_category_children', on_delete=models.CASCADE, null=True,
                               blank=True)

    def __str__(self):
        return self.name

serializers.py

class CategoryGetSerializer(serializers.ModelSerializer):
    children = RecursiveField(many=True, read_only=True)

    class Meta:
        model = Category
        fields = "__all__"

views.py

class CategoryView(ModelViewSet):
    pass

    def get_serializer_class(self):
        # return CategorySerializer

        if self.action == 'list':
            return CategoryGetSerializer
        else:
            return CategorySerializer

    queryset = Category.objects.filter(parent__isnull=True)

Response json

[
  {
    "id": 0,
    "children": [
      "string"
    ],
    "date_created": "2022-12-27T11:12:28.099Z",
    "date_updated": "2022-12-27T11:12:28.099Z",
    "active": true,
    "deleted_at": "2022-12-27T11:12:28.099Z",
    "name": "string",
    "slug": "4p7XC77HuaJPRhUyaUNGMMpcbLFmeWe0rwyr",
    "image": "string",
    "parent": 0
  }
]

No data is response here in children. but here parent has many ids. I want to all children serializers in children. How can i solve this problem???

Bumps wheel from 0.24.0 to 0.38.1.

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

I implemented basically the exact recursive model and RecursiveModelSerializer and Django throws maximum recursion depth exceeded while calling a Python object which is interesting, because we only have one parent relation in the database with only 3 objects.

class UnitSerializer(serializers.ModelSerializer):
    parent = RecursiveField(allow_null=False)
    address = AddressSerializer(read_only=True)
    type = serializers.StringRelatedField(read_only=True)
    properties = PropertySerializer(many=True, read_only=True)

    class Meta:
        fields = ('id', 'name', 'description', 'enabled', 'parent', 'type', 'address', 'properties')
        model = Unit
        depth = 3

is our serializer class and it doesn't work. I am using the latest Django 3.0.7 and DRF 3.11.0.

Store need

{
  'name': 'category 1',
  'children':[
    {'name': 'category 2'},
    {'name': 'category 3'},
  ]
}

I use djangorestframework and trying to write serializer for

class Category(MPTTModel):
    name = models.CharField(max_length=100)

    parent = TreeForeignKey('self', on_delete=models.CASCADE, null=True, blank=True, related_name='children')

    class MPTTMeta:
        order_insertion_by = ['name']

I made it

class CategorySerializer(serializers.ModelSerializer):
    class Meta:
        model = Category
        fields = ['id', 'name', 'children']
        read_only_fields = ['parents']

    # parent = serializers.ListField()
    children = RecursiveField('CategorySerializer', required=False, allow_null=True, many=True)

And I got the error TypeError: unhashable type: 'collections.OrderedDict'. It seems that the internal fields are not serialized.