Add django-mongodb-backend support

- https://github.com/mongodb/django-mongodb-backend

rest_framework/compat.py

@@ -16,6 +16,13 @@ def unicode_http_header(value):
     return value
 
 
+# django-mongodb-backend
+try:
+    from bson import ObjectId
+except ImportError:
+    ObjectId = None
+
+
 # django.contrib.postgres requires psycopg2
 try:
     from django.contrib.postgres import fields as postgres_fields

rest_framework/fields.py

@@ -35,6 +35,11 @@ try:
 except ImportError:
     pytz = None
 
+try:
+    from bson import ObjectId
+except ImportError:
+    ObjectId = None
+
 from rest_framework import ISO_8601
 from rest_framework.compat import ip_address_validators
 from rest_framework.exceptions import ErrorDetail, ValidationError
@@ -1745,6 +1750,15 @@ class HStoreField(DictField):
         )
 
 
+class ObjectIdRestField(Field):
+    def to_internal_value(self, data):
+        if not ObjectId.is_valid(data):
+            raise ValidationError('Invalid ObjectId')
+
+    def to_representation(self, value):
+        return str(value)
+
+
 class JSONField(Field):
     default_error_messages = {
         'invalid': _('Value must be valid JSON.')

rest_framework/serializers.py

@@ -27,7 +27,7 @@ from django.utils.functional import cached_property
 from django.utils.translation import gettext_lazy as _
 
 from rest_framework.compat import (
-    get_referenced_base_fields_from_q, postgres_fields
+    get_referenced_base_fields_from_q, postgres_fields, ObjectId
 )
 from rest_framework.exceptions import ErrorDetail, ValidationError
 from rest_framework.fields import get_error_detail
@@ -938,6 +938,9 @@ class ModelSerializer(Serializer):
         serializer_field_mapping[postgres_fields.HStoreField] = HStoreField
         serializer_field_mapping[postgres_fields.ArrayField] = ListField
         serializer_field_mapping[postgres_fields.JSONField] = JSONField
+    if ObjectId:
+        from .fields import ObjectIdRestField
+        serializer_field_mapping[models.AutoField] = ObjectIdRestField
     serializer_related_field = PrimaryKeyRelatedField
     serializer_related_to_field = SlugRelatedField
     serializer_url_field = HyperlinkedIdentityField