🎨 [#4908] Restructure register submission for JSON plugin

Makes more sense to keep static variables dict close to where it's used

src/openforms/registrations/contrib/json/plugin.py

@@ -2,11 +2,14 @@
 
 from django.utils.translation import gettext_lazy as _
 
+from zgw_consumers.client import build_client
+
 from openforms.submissions.models import Submission
 from openforms.variables.service import get_static_variables
 
 from ...base import BasePlugin, OptionsT  # openforms.registrations.base
 from ...registry import register  # openforms.registrations.registry
+from ...utils import execute_unless_result_exists
 from .config import JSONOptionsSerializer
 
 
@@ -16,12 +19,11 @@ class JSONRegistration(BasePlugin):
     configuration_options = JSONOptionsSerializer
 
     def register_submission(self, submission: Submission, options: OptionsT) -> None:
-        static_variables = get_static_variables(submission=submission)
-        static_variables_dict = {
-            variable.key: variable.initial_value for variable in static_variables
-        }
+        # TODO-4908: the email plugin works with a EmailConfig singleton model. Is that useful here?
+        # TODO-4908: add typing for options dict
 
         values = {}
+        # Encode (base64) and add attachments to values dict if they were specified in the form variables list
         if submission.attachments.exists():
             for attachment in submission.attachments:
                 if not attachment.form_key in options["form_variables"]:
@@ -33,6 +35,13 @@ def register_submission(self, submission: Submission, options: OptionsT) -> None
 
         # TODO-4908: what should the behaviour be when a form
         #  variable is not in the data or static variables?
+        # Create static variables dict
+        static_variables = get_static_variables(submission=submission)
+        static_variables_dict = {
+            variable.key: variable.initial_value for variable in static_variables
+        }
+
+        # Update values dict with relevant form data
         values.update({
             form_variable: submission.data.get(
                 form_variable, static_variables_dict.get(form_variable)
@@ -46,5 +55,6 @@ def register_submission(self, submission: Submission, options: OptionsT) -> None
         # TODO-4908: added return for testing purposes
         return {"values": values}
 
+    # TODO-4098: what to do in here?
     def check_config(self):
         pass