♻️ [#1068] -- refactor custom formio field types to use dynamic confi…

…g approach

Now it's just another flavour of mutating an existing component on
the fly, with the added functionality of making some network calls to
retrieve the relevant data.

This essentially does away with the whole special treatment of custom
field types. The use case of adding one or more components and
rebuilding the component tree is removed, as there has not been any
demand for this.

We do keep in mind it may at some point be needed to inject components
at other locations in the tree or do more advanced operations, but
the current implementation does not sit in the way of that approach.

Additionally, this fixes the bug where only top-level npFamilyMembers
components could function correctly, which is now properly recursive
for nested components.

src/openforms/custom_field_types/__init__.py

@@ -0,0 +1,8 @@
+import warnings
+
+warnings.warn(
+    "The 'openforms.custom_field_types' is deprecated and will be removed when "
+    "the functionality to query 'arbitrary' data sources is finished. For more info, "
+    "see https://github.com/open-formulieren/open-forms/issues/2169.",
+    DeprecationWarning,
+)

src/openforms/custom_field_types/tests/test_family_members.py

@@ -9,7 +9,7 @@
 
 from openforms.authentication.constants import AuthAttribute
 from openforms.contrib.brp.models import BRPConfig
-from openforms.forms.custom_field_types import handle_custom_types
+from openforms.formio.service import get_dynamic_configuration
 from openforms.prefill.contrib.haalcentraal.tests.test_plugin import load_binary_mock
 from openforms.registrations.contrib.zgw_apis.tests.factories import ServiceFactory
 from openforms.submissions.tests.factories import SubmissionFactory
@@ -24,47 +24,50 @@
 
 
 class FamilyMembersCustomFieldTypeTest(TestCase):
-    @patch(
-        "openforms.custom_field_types.family_members.get_np_children_haal_centraal",
-        return_value=[("222333444", "Billy Doe"), ("333444555", "Jane Doe")],
-    )
-    def test_get_values_for_custom_field(self, m):
-        configuration = {
-            "display": "form",
-            "components": [
+    @patch("openforms.formio.components.custom.NPFamilyMembers._get_handler")
+    def test_get_values_for_custom_field(self, mock_get_handler):
+        mock_get_handler.return_value.return_value = [
+            ("222333444", "Billy Doe"),
+            ("333444555", "Jane Doe"),
+        ]
+        submission = SubmissionFactory.from_components(
+            [
                 {
                     "key": "npFamilyMembers",
                     "type": "npFamilyMembers",
                     "label": "FamilyMembers",
                     "values": [{"label": "", "value": ""}],
                 },
             ],
-        }
-        submission = SubmissionFactory.create(
             auth_info__attribute=AuthAttribute.bsn,
             auth_info__value="111222333",
-            form__generate_minimal_setup=True,
-            form__formstep__form_definition__configuration=configuration,
         )
         config = FamilyMembersTypeConfig.get_solo()
         config.data_api = FamilyMembersDataAPIChoices.haal_centraal
         config.save()
+        formio_wrapper = (
+            submission.submissionstep_set.get().form_step.form_definition.configuration_wrapper
+        )
 
-        rewritten_configuration = handle_custom_types(configuration, submission)
+        updated_config_wrapper = get_dynamic_configuration(
+            formio_wrapper,
+            request=None,
+            submission=submission,
+        )
 
-        rewritten_component = rewritten_configuration["components"][0]
+        rewritten_component = updated_config_wrapper["npFamilyMembers"]
         self.assertEqual("selectboxes", rewritten_component["type"])
         self.assertFalse(rewritten_component["fieldSet"])
         self.assertFalse(rewritten_component["inline"])
         self.assertEqual("checkbox", rewritten_component["inputType"])
         self.assertEqual(2, len(rewritten_component["values"]))
-        self.assertDictEqual(
-            {"value": "222333444", "label": "Billy Doe"},
+        self.assertEqual(
             rewritten_component["values"][0],
+            {"value": "222333444", "label": "Billy Doe"},
         )
-        self.assertDictEqual(
-            {"value": "333444555", "label": "Jane Doe"},
+        self.assertEqual(
             rewritten_component["values"][1],
+            {"value": "333444555", "label": "Jane Doe"},
         )
 
     def test_get_children_haal_centraal(self):

src/openforms/formio/components/custom.py

@@ -1,11 +1,14 @@
 import logging
+from typing import Callable
 
+from openforms.authentication.constants import AuthAttribute
+from openforms.submissions.models import Submission
 from openforms.typing import DataMapping
 from openforms.utils.date import format_date_value
 
 from ..dynamic_config.date import FormioDateComponent, mutate as mutate_date
 from ..formatters.custom import DateFormatter, MapFormatter
-from ..formatters.formio import TextFieldFormatter
+from ..formatters.formio import DefaultFormatter, TextFieldFormatter
 from ..registry import BasePlugin, register
 from ..typing import Component
 from ..utils import conform_to_mask
@@ -22,7 +25,7 @@ def normalizer(component: FormioDateComponent, value: str) -> str:
         return format_date_value(value)
 
     def mutate_config_dynamically(
-        self, component: FormioDateComponent, data: DataMapping
+        self, component: FormioDateComponent, submission: Submission, data: DataMapping
     ) -> None:
         """
         Implement the behaviour for our custom date component options.
@@ -58,3 +61,73 @@ def normalizer(component: Component, value: str) -> str:
                 "Could not conform value '%s' to input mask '%s', returning original value."
             )
             return value
+
+
+@register("npFamilyMembers")
+class NPFamilyMembers(BasePlugin):
+    # not actually relevant, as we transform the component into a different type
+    formatter = DefaultFormatter
+
+    @staticmethod
+    def _get_handler() -> Callable[[str], list[tuple[str, str]]]:
+        # TODO: move these into a subpackage of openforms.formio
+        from openforms.custom_field_types.constants import FamilyMembersDataAPIChoices
+        from openforms.custom_field_types.handlers.haal_centraal import (
+            get_np_children_haal_centraal,
+        )
+        from openforms.custom_field_types.handlers.stuf_bg import (
+            get_np_children_stuf_bg,
+        )
+        from openforms.custom_field_types.models import FamilyMembersTypeConfig
+
+        handlers = {
+            FamilyMembersDataAPIChoices.haal_centraal: get_np_children_haal_centraal,
+            FamilyMembersDataAPIChoices.stuf_bg: get_np_children_stuf_bg,
+        }
+        config = FamilyMembersTypeConfig.get_solo()
+        return handlers[config.data_api]
+
+    @classmethod
+    def mutate_config_dynamically(
+        cls, component: Component, submission: Submission, data: DataMapping
+    ) -> None:
+        # Check authentication details/status before proceeding
+        if not submission.is_authenticated:
+            raise RuntimeError("No authenticated person!")
+        if submission.auth_info.attribute != AuthAttribute.bsn:
+            raise RuntimeError("No BSN found in the authentication details.")
+
+        bsn = submission.auth_info.value
+
+        component.update(
+            {
+                "type": "selectboxes",
+                "fieldSet": False,
+                "inline": False,
+                "inputType": "checkbox",
+            }
+        )
+
+        if "mask" in component:
+            del component["mask"]
+
+        existing_values = component.get("values", [])
+        empty_option = {
+            "label": "",
+            "value": "",
+        }
+        if not existing_values or existing_values[0] == empty_option:
+            handler = cls._get_handler()
+            # make the API call
+            # TODO: this should eventually be replaced with logic rules/variables that
+            # retrieve data from an "arbitrary source", which will cause the data to
+            # become available in the ``data`` argument instead.
+            child_choices = handler(bsn)
+
+            component["values"] = [
+                {
+                    "label": label,
+                    "value": value,
+                }
+                for value, label in child_choices
+            ]

src/openforms/formio/dynamic_config/__init__.py

@@ -7,6 +7,7 @@
 
 from rest_framework.request import Request
 
+from openforms.submissions.models import Submission
 from openforms.typing import DataMapping
 
 from ..datastructures import FormioConfigurationWrapper
@@ -17,6 +18,7 @@
 
 def rewrite_formio_components(
     configuration_wrapper: FormioConfigurationWrapper,
+    submission: Submission,
     data: Optional[DataMapping] = None,
 ) -> FormioConfigurationWrapper:
     """
@@ -33,7 +35,7 @@ def rewrite_formio_components(
     """
     data = data or {}  # normalize
     for component in configuration_wrapper:
-        register.update_config(component, data=data)
+        register.update_config(component, submission=submission, data=data)
     return configuration_wrapper
 
 

src/openforms/formio/registry.py

@@ -21,7 +21,6 @@
 from openforms.plugins.registry import BaseRegistry
 from openforms.typing import DataMapping
 
-from .datastructures import FormioConfigurationWrapper
 from .typing import Component
 
 if TYPE_CHECKING:
@@ -74,7 +73,7 @@ def verbose_name(self):
         return _("{type} component").format(type=self.identifier.capitalize())
 
     def mutate_config_dynamically(
-        self, component: Component, data: DataMapping
+        self, component: Component, submission: "Submission", data: DataMapping
     ) -> None:  # pragma: nocover
         ...
 
@@ -109,7 +108,10 @@ def format(self, component: Component, value: Any, as_html=False):
         return formatter(component, value)
 
     def update_config(
-        self, component: Component, data: DataMapping | None = None
+        self,
+        component: Component,
+        submission: "Submission",
+        data: DataMapping | None = None,
     ) -> None:
         """
         Mutate the component configuration in place.
@@ -118,19 +120,19 @@ def update_config(
         for example) to work.
         """
         # if there is no plugin registered for the component, return the input
-        if (component_type := component["type"]) not in register:
+        if (component_type := component["type"]) not in self:
             return
 
         # invoke plugin if exists
         plugin = self[component_type]
-        plugin.mutate_config_dynamically(component, data)
+        plugin.mutate_config_dynamically(component, submission, data)
 
     def update_config_for_request(self, component: Component, request: Request) -> None:
         """
         Mutate the component in place for the given request context.
         """
         # if there is no plugin registered for the component, return the input
-        if (component_type := component["type"]) not in register:
+        if (component_type := component["type"]) not in self:
             return
 
         # invoke plugin if exists
@@ -140,21 +142,6 @@ def update_config_for_request(self, component: Component, request: Request) -> N
 
         rewriter(component, request)
 
-    def handle_custom_types(
-        self,
-        configuration: FormioConfigurationWrapper,
-        submission: "Submission",
-    ):
-        """
-        Process custom backend-only formio types.
-
-        Formio types can be transformed in the context of a given
-        :class:`openforms.submissions.models.Submission` and ultimately manifest as
-        modified or standard Formio types, essentially performing some sort of "rewrite"
-        of the Formio configuration object.
-        """
-        raise NotImplementedError()
-
 
 # Sentinel to provide the default registry. You can easily instantiate another
 # :class:`Registry` object to use as dependency injection in tests.

src/openforms/formio/service.py

@@ -13,7 +13,6 @@
 import elasticapm
 from rest_framework.request import Request
 
-from openforms.forms.custom_field_types import handle_custom_types
 from openforms.prefill import inject_prefill
 from openforms.submissions.models import Submission
 from openforms.typing import DataMapping
@@ -62,12 +61,7 @@ def get_dynamic_configuration(
 
     The configuration is modified in the context of the provided :arg:`submission`.
     """
-    # TODO: see if we can make the config wrapper smart enough to deal with this
-    config_wrapper.configuration = handle_custom_types(
-        config_wrapper.configuration, submission=submission
-    )
-
-    rewrite_formio_components(config_wrapper, data=data)
+    rewrite_formio_components(config_wrapper, submission=submission, data=data)
 
     # prefill is still 'special' even though it uses variables, as we specifically
     # set the `defaultValue` key to the resulting variable.