attempt to save again if deadlock given for draft data save w/ burnettk (#410)

Co-authored-by: jasquat <jasquat@users.noreply.github.com>

spiffworkflow-backend/src/spiffworkflow_backend/routes/tasks_controller.py

@@ -14,6 +14,7 @@ from flask import jsonify
 from flask import make_response
 from flask import stream_with_context
 from flask.wrappers import Response
+from MySQLdb import OperationalError  # type: ignore
 from SpiffWorkflow.bpmn.exceptions import WorkflowTaskException  # type: ignore
 from SpiffWorkflow.bpmn.workflow import BpmnWorkflow  # type: ignore
 from SpiffWorkflow.task import Task as SpiffTask  # type: ignore
@@ -586,13 +587,21 @@ def task_save_draft(
     principal = _find_principal_or_raise()
     process_instance = _find_process_instance_by_id_or_raise(process_instance_id)
     if not process_instance.can_submit_task():
-        raise ApiError(
+        return Response(
-            error_code="process_instance_not_runnable",
+            json.dumps(
-            message=(
+                {
+                    "ok": True,
+                    "saved": False,
+                    "message": (
                         f"Process Instance ({process_instance.id}) has status "
                         f"{process_instance.status} which does not allow draft data to be saved."
                     ),
-            status_code=400,
+                    "process_model_identifier": process_instance.process_model_identifier,
+                    "process_instance_id": process_instance_id,
+                }
+            ),
+            status=200,
+            mimetype="application/json",
         )
 
     try:
@@ -610,12 +619,30 @@ def task_save_draft(
         if json_data_dict is not None:
             JsonDataModel.insert_or_update_json_data_dict(json_data_dict)
             db.session.add(task_draft_data)
+            try:
                 db.session.commit()
+            except OperationalError as exception:
+                db.session.rollback()
+                if "Deadlock" in str(exception):
+                    task_draft_data = TaskService.task_draft_data_from_task_model(task_model)
+                    # if we do not find a task_draft_data record, that means it was deleted when the form was submitted
+                    # and we therefore have no need to save draft data
+                    if task_draft_data is not None:
+                        json_data_dict = TaskService.update_task_data_on_task_model_and_return_dict_if_updated(
+                            task_draft_data, body, "saved_form_data_hash"
+                        )
+                        if json_data_dict is not None:
+                            JsonDataModel.insert_or_update_json_data_dict(json_data_dict)
+                            db.session.add(task_draft_data)
+                            db.session.commit()
+                else:
+                    raise exception
 
     return Response(
         json.dumps(
             {
                 "ok": True,
+                "saved": True,
                 "process_model_identifier": process_instance.process_model_identifier,
                 "process_instance_id": process_instance_id,
             }

spiffworkflow-frontend/src/routes/TaskShow.tsx

@@ -21,7 +21,7 @@ import {
   modifyProcessIdentifierForPathParam,
   recursivelyChangeNullAndUndefined,
 } from '../helpers';
-import { ErrorForDisplay, EventDefinition, Task } from '../interfaces';
+import { EventDefinition, Task } from '../interfaces';
 import ProcessBreadcrumb from '../components/ProcessBreadcrumb';
 import InstructionsForEndUser from '../components/InstructionsForEndUser';
 import TypeaheadWidget from '../rjsf/custom_widgets/TypeaheadWidget/TypeaheadWidget';
@@ -77,17 +77,6 @@ export default function TaskShow() {
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [params]);
 
-  const handleAutoSaveError = (error: ErrorForDisplay) => {
-    if (
-      error.error_code &&
-      error.error_code === 'process_instance_not_runnable'
-    ) {
-      return undefined;
-    }
-    addError(error);
-    return undefined;
-  };
-
   // Before we auto-saved form data, we remembered what data was in the form, and then created a synthetic submit event
   // in order to implement a "Save and close" button. That button no longer saves (since we have auto-save), but the crazy
   // frontend code to support that Save and close button is here, in case we need to reference that someday:
@@ -106,7 +95,6 @@ export default function TaskShow() {
       postBody: formData,
       httpMethod: 'POST',
       successCallback: successCallbackToUse,
-      failureCallback: handleAutoSaveError,
     });
     return undefined;
   };