Fixed #30583 -- Fixed handling JSONFields in XML serializer.

Co-authored-by: Chason Chaffin <chason@gmail.com>

django/core/serializers/xml_serializer.py

@@ -1,7 +1,7 @@
 """
 XML serializer.
 """
-
+import json
 from xml.dom import pulldom
 from xml.sax import handler
 from xml.sax.expatreader import ExpatParser as _ExpatParser
@@ -75,8 +75,13 @@ class Serializer(base.Serializer):
 
         # Get a "string version" of the object's data.
         if getattr(obj, field.name) is not None:
+            value = field.value_to_string(obj)
+            if field.get_internal_type() == 'JSONField':
+                # Dump value since JSONField.value_to_string() doesn't output
+                # strings.
+                value = json.dumps(value, cls=field.encoder)
             try:
-                self.xml.characters(field.value_to_string(obj))
+                self.xml.characters(value)
             except UnserializableContentError:
                 raise ValueError("%s.%s (pk:%s) contains unserializable characters" % (
                     obj.__class__.__name__, field.name, obj.pk))
@@ -232,6 +237,9 @@ class Deserializer(base.Deserializer):
                     value = None
                 else:
                     value = field.to_python(getInnerText(field_node).strip())
+                    # Load value since JSONField.to_python() outputs strings.
+                    if field.get_internal_type() == 'JSONField':
+                        value = json.loads(value, cls=field.decoder)
                 data[field.name] = value
 
         obj = base.build_instance(Model, data, self.db)

tests/model_fields/test_jsonfield.py

@@ -149,6 +149,21 @@ class TestSerialization(SimpleTestCase):
                 )[0].object
                 self.assertEqual(instance.value, value)
 
+    def test_xml_serialization(self):
+        test_xml_data = (
+            '<django-objects version="1.0">'
+            '<object model="model_fields.nullablejsonmodel">'
+            '<field name="value" type="JSONField">%s'
+            '</field></object></django-objects>'
+        )
+        for value, serialized in self.test_values:
+            with self.subTest(value=value):
+                instance = NullableJSONModel(value=value)
+                data = serializers.serialize('xml', [instance], fields=['value'])
+                self.assertXMLEqual(data, test_xml_data % serialized)
+                new_instance = list(serializers.deserialize('xml', data))[0].object
+                self.assertEqual(new_instance.value, instance.value)
+
 
 @skipUnlessDBFeature('supports_json_field')
 class TestSaveLoad(TestCase):