Pause/resume process instances (#2)

Collab with @cullerton

spiffworkflow-backend/src/spiffworkflow_backend/api.yml

@@ -670,6 +670,72 @@ paths:
               schema:
                 $ref: "#/components/schemas/OkTrue"
 
+  /process-models/{process_group_id}/{process_model_id}/process-instances/{process_instance_id}/suspend:
+    parameters:
+      - name: process_group_id
+        in: path
+        required: true
+        description: The unique id of an existing process group
+        schema:
+          type: string
+      - name: process_model_id
+        in: path
+        required: true
+        description: The unique id of an existing process model.
+        schema:
+          type: string
+      - name: process_instance_id
+        in: path
+        required: true
+        description: The unique id of an existing process instance.
+        schema:
+          type: integer
+    post:
+      operationId: spiffworkflow_backend.routes.process_api_blueprint.process_instance_suspend
+      summary: Suspend a process instance
+      tags:
+        - Process Instances
+      responses:
+        "200":
+          description: Empty ok true response on successful suspension.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/OkTrue"
+
+  /process-models/{process_group_id}/{process_model_id}/process-instances/{process_instance_id}/resume:
+    parameters:
+      - name: process_group_id
+        in: path
+        required: true
+        description: The unique id of an existing process group
+        schema:
+          type: string
+      - name: process_model_id
+        in: path
+        required: true
+        description: The unique id of an existing process model.
+        schema:
+          type: string
+      - name: process_instance_id
+        in: path
+        required: true
+        description: The unique id of an existing process instance.
+        schema:
+          type: integer
+    post:
+      operationId: spiffworkflow_backend.routes.process_api_blueprint.process_instance_resume
+      summary: Resume a process instance
+      tags:
+        - Process Instances
+      responses:
+        "200":
+          description: Empty ok true response on successful resume.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/OkTrue"
+
   /process-models/{process_group_id}/{process_model_id}/process-instances/reports:
     parameters:
       - name: process_group_id

spiffworkflow-backend/src/spiffworkflow_backend/models/active_task.py

@@ -61,6 +61,7 @@ class ActiveTaskModel(SpiffworkflowBaseDBModel):
             task.task_status,
             data=task_data,
             process_instance_id=task.process_instance_id,
+            process_instance_status=task.status,
         )
         if hasattr(task, "process_model_display_name"):
             new_task.process_model_display_name = task.process_model_display_name

spiffworkflow-backend/src/spiffworkflow_backend/models/task.py

@@ -111,6 +111,7 @@ class Task:
         process_name: str = "",
         properties: Union[dict, None] = None,
         process_instance_id: Union[int, None] = None,
+        process_instance_status: Union[str, None] = None,
         process_model_display_name: Union[str, None] = None,
         process_group_identifier: Union[str, None] = None,
         process_model_identifier: Union[str, None] = None,
@@ -134,6 +135,7 @@ class Task:
             self.data = {}
 
         self.process_instance_id = process_instance_id
+        self.process_instance_status = process_instance_status
         self.process_group_identifier = process_group_identifier
         self.process_model_identifier = process_model_identifier
         self.process_model_display_name = process_model_display_name
@@ -178,6 +180,7 @@ class Task:
             "process_name": self.process_name,
             "properties": self.properties,
             "process_instance_id": self.process_instance_id,
+            "process_instance_status": self.process_instance_status,
             "process_model_display_name": self.process_model_display_name,
             "process_group_identifier": self.process_group_identifier,
             "process_model_identifier": self.process_model_identifier,

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

@@ -45,6 +45,7 @@ from spiffworkflow_backend.models.process_group import ProcessGroupSchema
 from spiffworkflow_backend.models.process_instance import ProcessInstanceApiSchema
 from spiffworkflow_backend.models.process_instance import ProcessInstanceModel
 from spiffworkflow_backend.models.process_instance import ProcessInstanceModelSchema
+from spiffworkflow_backend.models.process_instance import ProcessInstanceStatus
 from spiffworkflow_backend.models.process_instance_report import (
     ProcessInstanceReportModel,
 )
@@ -452,6 +453,34 @@ def process_instance_terminate(
     return Response(json.dumps({"ok": True}), status=200, mimetype="application/json")
 
 
+def process_instance_suspend(
+    process_group_id: str,
+    process_model_id: str,
+    process_instance_id: int,
+) -> flask.wrappers.Response:
+    """Process_instance_suspend."""
+    process_instance = ProcessInstanceService().get_process_instance(
+        process_instance_id
+    )
+    processor = ProcessInstanceProcessor(process_instance)
+    processor.suspend()
+    return Response(json.dumps({"ok": True}), status=200, mimetype="application/json")
+
+
+def process_instance_resume(
+    process_group_id: str,
+    process_model_id: str,
+    process_instance_id: int,
+) -> flask.wrappers.Response:
+    """Process_instance_resume."""
+    process_instance = ProcessInstanceService().get_process_instance(
+        process_instance_id
+    )
+    processor = ProcessInstanceProcessor(process_instance)
+    processor.resume()
+    return Response(json.dumps({"ok": True}), status=200, mimetype="application/json")
+
+
 def process_instance_log_list(
     process_group_id: str,
     process_model_id: str,
@@ -895,6 +924,7 @@ def task_list_my_tasks(page: int = 1, per_page: int = 100) -> flask.wrappers.Res
         .add_columns(
             ProcessInstanceModel.process_model_identifier,
             ProcessInstanceModel.process_group_identifier,
+            ProcessInstanceModel.status,
             ActiveTaskModel.task_data,
             ActiveTaskModel.task_name,
             ActiveTaskModel.task_title,
@@ -947,6 +977,14 @@ def process_instance_task_list(
 def task_show(process_instance_id: int, task_id: str) -> flask.wrappers.Response:
     """Task_show."""
     process_instance = find_process_instance_by_id_or_raise(process_instance_id)
+
+    if process_instance.status == ProcessInstanceStatus.suspended.value:
+        raise ApiError(
+            error_code="error_suspended",
+            message="The process instance is suspended",
+            status_code=400,
+        )
+
     process_model = get_process_model(
         process_instance.process_model_identifier,
         process_instance.process_group_identifier,

spiffworkflow-backend/src/spiffworkflow_backend/services/process_instance_processor.py

@@ -1133,3 +1133,15 @@ class ProcessInstanceProcessor:
         self.process_instance_model.status = "terminated"
         db.session.add(self.process_instance_model)
         db.session.commit()
+
+    def suspend(self) -> None:
+        """Suspend."""
+        self.process_instance_model.status = ProcessInstanceStatus.suspended.value
+        db.session.add(self.process_instance_model)
+        db.session.commit()
+
+    def resume(self) -> None:
+        """Resume."""
+        self.process_instance_model.status = ProcessInstanceStatus.waiting.value
+        db.session.add(self.process_instance_model)
+        db.session.commit()

spiffworkflow-frontend/src/routes/HomePage.tsx

@@ -62,8 +62,13 @@ export default function HomePage() {
             {rowToUse.title}
           </td>
           <td>{rowToUse.state}</td>
+          <td>{rowToUse.process_instance_status}</td>
           <td>
-            <Button variant="primary" href={taskUrl}>
+            <Button
+              variant="primary"
+              href={taskUrl}
+              hidden={rowToUse.process_instance_status === 'suspended'}
+            >
               Complete Task
             </Button>
           </td>
@@ -78,6 +83,7 @@ export default function HomePage() {
             <th>Process Instance</th>
             <th>Task Name</th>
             <th>Status</th>
+            <th>Process Instance Status</th>
             <th>Actions</th>
           </tr>
         </thead>

spiffworkflow-frontend/src/routes/ProcessInstanceShow.tsx

@@ -53,6 +53,22 @@ export default function ProcessInstanceShow() {
     });
   };
 
+  const suspendProcessInstance = () => {
+    HttpService.makeCallToBackend({
+      path: `/process-models/${params.process_group_id}/${params.process_model_id}/process-instances/${params.process_instance_id}/suspend`,
+      successCallback: refreshPage,
+      httpMethod: 'POST',
+    });
+  };
+
+  const resumeProcessInstance = () => {
+    HttpService.makeCallToBackend({
+      path: `/process-models/${params.process_group_id}/${params.process_model_id}/process-instances/${params.process_instance_id}/resume`,
+      successCallback: refreshPage,
+      httpMethod: 'POST',
+    });
+  };
+
   const getTaskIds = () => {
     const taskIds = { completed: [], readyOrWaiting: [] };
     if (tasks) {
@@ -126,6 +142,32 @@ export default function ProcessInstanceShow() {
     return <div />;
   };
 
+  const suspendButton = (processInstanceToUse: any) => {
+    if (
+      ['complete', 'terminated', 'faulted', 'suspended'].indexOf(
+        processInstanceToUse.status
+      ) === -1
+    ) {
+      return (
+        <Button onClick={suspendProcessInstance} variant="warning">
+          Suspend
+        </Button>
+      );
+    }
+    return <div />;
+  };
+
+  const resumeButton = (processInstanceToUse: any) => {
+    if (processInstanceToUse.status === 'suspended') {
+      return (
+        <Button onClick={resumeProcessInstance} variant="warning">
+          Resume
+        </Button>
+      );
+    }
+    return <div />;
+  };
+
   const handleClickedDiagramTask = (shapeElement: any) => {
     if (tasks) {
       const matchingTask = tasks.find(
@@ -217,6 +259,8 @@ export default function ProcessInstanceShow() {
             buttonLabel="Delete"
           />
           {terminateButton(processInstanceToUse)}
+          {suspendButton(processInstanceToUse)}
+          {resumeButton(processInstanceToUse)}
         </Stack>
         {getInfoTag(processInstanceToUse)}
         {taskDataDisplayArea()}