🚩 Add feature flag to disable formio validation in backend

src/openforms/config/admin.py

@@ -161,6 +161,7 @@ class GlobalConfigurationAdmin(TranslationAdmin, SingletonModelAdmin):
                     "enable_demo_plugins",
                     "allow_empty_initiator",
                     "payment_order_id_prefix",
+                    "enable_backend_formio_validation",
                 ),
             },
         ),

src/openforms/config/migrations/0056_globalconfiguration_enable_backend_formio_validation.py

@@ -0,0 +1,20 @@
+# Generated by Django 4.2.11 on 2024-04-08 09:38
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("config", "0055_remove_globalconfiguration_enable_react_formio_builder"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="globalconfiguration",
+            name="enable_backend_formio_validation",
+            field=models.BooleanField(
+                default=True, verbose_name="enabled backend formio validation"
+            ),
+        ),
+    ]

src/openforms/config/models/config.py

@@ -403,6 +403,11 @@ class GlobalConfiguration(SingletonModel):
         help_text=_("When enabled, information about the used SDK is displayed."),
     )
 
+    enable_backend_formio_validation = models.BooleanField(
+        _("enabled backend formio validation"),
+        default=True,
+    )
+
     # Removing data configurations
     successful_submissions_removal_limit = models.PositiveIntegerField(
         _("successful submission removal limit"),

src/openforms/submissions/api/validation.py

@@ -11,6 +11,7 @@
 from rest_framework import serializers
 
 from openforms.api.utils import mark_experimental
+from openforms.config.models import GlobalConfiguration
 from openforms.formio.service import build_serializer
 
 from ..form_logic import check_submission_logic
@@ -47,6 +48,11 @@ def validate_contains_blocked_steps(self, value):
             )
 
     def validate(self, attrs: dict):
+        config = GlobalConfiguration.get_solo()
+        assert isinstance(config, GlobalConfiguration)
+        if not config.enable_backend_formio_validation:
+            return attrs
+
         submission: Submission = self.context["submission"]
 
         formio_validation_errors = []

src/openforms/submissions/tests/test_submission_completion.py

@@ -117,6 +117,41 @@ def test_component_level_validation(self):
         ]
         self.assertIn("steps.0.data.firstName", invalid_param_names)
 
+    @patch(
+        "openforms.submissions.api.validation.GlobalConfiguration.get_solo",
+        return_value=GlobalConfiguration(enable_backend_formio_validation=False),
+    )
+    def test_component_level_validation_disabled_via_feature_flag(self, m_solo):
+        submission = SubmissionFactory.create(
+            form__generate_minimal_setup=True,
+            form__formstep__form_definition__configuration={
+                "components": [
+                    {
+                        "type": "textfield",
+                        "key": "firstName",
+                        "label": "First name",
+                        "validate": {
+                            "required": True,
+                            "maxLength": 20,
+                        },
+                    }
+                ]
+            },
+        )
+        SubmissionStepFactory.create(
+            submission=submission,
+            form_step=submission.form.formstep_set.get(),
+            data={
+                "firstName": "this value is longer than twenty characters and should not validate"
+            },
+        )
+        self._add_submission_to_session(submission)
+        endpoint = reverse("api:submission-complete", kwargs={"uuid": submission.uuid})
+
+        response = self.client.post(endpoint, {"privacy_policy_accepted": True})
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+
     @patch("openforms.submissions.api.mixins.on_post_submission_event")
     @freeze_time("2020-12-11T10:53:19+01:00")
     def test_complete_submission(self, mock_on_post_submission_event):