🐛 [#4980] Revise how attachments are processed

There was a bug with the previous attachment processing, where attachments would get overwritten if multiple were uploaded

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

@@ -4,9 +4,10 @@
 
 from zgw_consumers.client import build_client
 
-from openforms.submissions.models import Submission
+from openforms.formio.typing import Component
+from openforms.submissions.models import Submission, SubmissionValueVariable, \
+    SubmissionFileAttachment
 from openforms.typing import JSONObject
-from openforms.variables.service import get_static_variables
 
 from ...base import BasePlugin  # openforms.registrations.base
 from ...registry import register  # openforms.registrations.registry
@@ -33,15 +34,8 @@ def register_submission(
             if key in options["form_variables"]
         }
 
-        # Encode (base64) and add attachments to values dict if their form keys were specified in the
-        # form variables list
-        for attachment in submission.attachments:
-            if attachment.form_key not in options["form_variables"]:
-                continue
-            options["form_variables"].remove(attachment.form_key)
-            with attachment.content.open("rb") as f:
-                f.seek(0)
-                values[attachment.form_key] = base64.b64encode(f.read()).decode()
+        # Process attachments
+        self.process_variables(submission, values)
 
         # Generate schema
         # TODO: will be added in #4980. Hardcoded example for now.
@@ -76,3 +70,57 @@ def register_submission(
     def check_config(self) -> None:
         # Config checks are not really relevant for this plugin right now
         pass
+
+    @staticmethod
+    def process_variables(submission: Submission, values: JSONObject):
+        """Process variables.
+
+        File components need special treatment, as we send the content of the file
+        encoded with base64, instead of the output from the serializer.
+        """
+        state = submission.load_submission_value_variables_state()
+
+        for key in values.keys():
+            variable = state.variables.get(key)
+            if variable is None:
+                # None for static variables
+                continue
+
+            component = get_component(variable)
+            if component is None or component["type"] != "file":
+                continue
+
+            encoded_attachments = {
+                attachment.file_name: encode_attachment(attachment)
+                for attachment in submission.attachments
+                if attachment.form_key == key
+            }
+            multiple = component.get("multiple", False)
+            values[key] = (
+                encoded_attachments
+                if multiple
+                else list(encoded_attachments.values())[0]
+            )
+
+
+def encode_attachment(attachment: SubmissionFileAttachment) -> str:
+    """Encode an attachment using base64
+
+    :param attachment: Attachment to encode
+    :returns: Encoded base64 data as a string
+    """
+    with attachment.content.open("rb") as f:
+        f.seek(0)
+        return base64.b64encode(f.read()).decode()
+
+
+def get_component(variable: SubmissionValueVariable) -> Component:
+    """Get the component from a submission value variable.
+
+    :param variable: SubmissionValueVariable
+    :return component: Component
+    """
+    config_wrapper = variable.form_variable.form_definition.configuration_wrapper
+    component = config_wrapper.component_map[variable.key]
+
+    return component

src/openforms/registrations/contrib/json_dump/tests/test_backend.py

@@ -18,7 +18,7 @@
 VCR_TEST_FILES = Path(__file__).parent / "files"
 
 
-class JSONDumpBackendTests(OFVCRMixin, TestCase):
+class JSONDumpBackendTests(TestCase):
     VCR_TEST_FILES = VCR_TEST_FILES
 
     def test_submission_with_json_dump_backend(self):
@@ -116,3 +116,65 @@ def test_exception_raised_when_service_returns_unexpected_status_code(self):
 
         with self.assertRaises(RequestException):
             json_plugin.register_submission(submission, json_form_options)
+
+    def test_multiple_file_uploads(self):
+        submission = SubmissionFactory.from_components(
+            [{"key": "file", "type": "file", "multiple": True}],
+            completed=True,
+            submitted_data={
+                "file": [
+                    {
+                        "url": "some://url",
+                        "name": "file1.txt",
+                        "type": "application/text",
+                        "originalName": "file1.txt",
+                    },
+                    {
+                        "url": "some://url",
+                        "name": "file2.txt",
+                        "type": "application/text",
+                        "originalName": "file2.txt",
+                    }
+                ],
+            },
+        )
+
+        SubmissionFileAttachmentFactory.create(
+            form_key="file",
+            submission_step=submission.submissionstep_set.get(),
+            file_name="file1.txt",
+            content_type="application/text",
+            content__data=b"This is example content.",
+            _component_configuration_path="components.2",
+            _component_data_path="file",
+        )
+
+        SubmissionFileAttachmentFactory.create(
+            form_key="file",
+            submission_step=submission.submissionstep_set.get(),
+            file_name="file2.txt",
+            content_type="application/text",
+            content__data=b"Content example is this.",
+            _component_configuration_path="components.2",
+            _component_data_path="file",
+        )
+
+        json_form_options = dict(
+            service=(ServiceFactory(api_root="http://localhost:80/")),
+            relative_api_endpoint="json_plugin",
+            form_variables=["file"],
+        )
+        json_plugin = JSONDumpRegistration("json_registration_plugin")
+        set_submission_reference(submission)
+
+        expected_values = {
+            "file": {
+                "file1.txt": "VGhpcyBpcyBleGFtcGxlIGNvbnRlbnQu",  # This is example content.
+                "file2.txt": "Q29udGVudCBleGFtcGxlIGlzIHRoaXMu",  # Content example is this.
+            },
+        }
+
+        res = json_plugin.register_submission(submission, json_form_options)
+        res_json = res["api_response"]
+
+        self.assertEqual(res_json["data"]["values"], expected_values)