feat: Persist Variables for Enhanced Debugging Workflow (#20699)

This pull request introduces a feature aimed at improving the debugging experience during workflow editing. With the addition of variable persistence, the system will automatically retain the output variables from previously executed nodes. These persisted variables can then be reused when debugging subsequent nodes, eliminating the need for repetitive manual input.

By streamlining this aspect of the workflow, the feature minimizes user errors and significantly reduces debugging effort, offering a smoother and more efficient experience.

Key highlights of this change:

- Automatic persistence of output variables for executed nodes.
- Reuse of persisted variables to simplify input steps for nodes requiring them (e.g., `code`, `template`, `variable_assigner`).
- Enhanced debugging experience with reduced friction.

Closes #19735.

api/controllers/console/app/workflow.py

@@ -1,5 +1,6 @@
 import json
 import logging
+from collections.abc import Sequence
 from typing import cast
 
 from flask import abort, request
@@ -18,10 +19,12 @@ from controllers.console.app.error import (
 from controllers.console.app.wraps import get_app_model
 from controllers.console.wraps import account_initialization_required, setup_required
 from controllers.web.error import InvokeRateLimitError as InvokeRateLimitHttpError
+from core.app.app_config.features.file_upload.manager import FileUploadConfigManager
 from core.app.apps.base_app_queue_manager import AppQueueManager
 from core.app.entities.app_invoke_entities import InvokeFrom
+from core.file.models import File
 from extensions.ext_database import db
-from factories import variable_factory
+from factories import file_factory, variable_factory
 from fields.workflow_fields import workflow_fields, workflow_pagination_fields
 from fields.workflow_run_fields import workflow_run_node_execution_fields
 from libs import helper
@@ -30,6 +33,7 @@ from libs.login import current_user, login_required
 from models import App
 from models.account import Account
 from models.model import AppMode
+from models.workflow import Workflow
 from services.app_generate_service import AppGenerateService
 from services.errors.app import WorkflowHashNotEqualError
 from services.errors.llm import InvokeRateLimitError
@@ -38,6 +42,24 @@ from services.workflow_service import DraftWorkflowDeletionError, WorkflowInUseE
 logger = logging.getLogger(__name__)
 
 
+# TODO(QuantumGhost): Refactor existing node run API to handle file parameter parsing
+# at the controller level rather than in the workflow logic. This would improve separation
+# of concerns and make the code more maintainable.
+def _parse_file(workflow: Workflow, files: list[dict] | None = None) -> Sequence[File]:
+    files = files or []
+
+    file_extra_config = FileUploadConfigManager.convert(workflow.features_dict, is_vision=False)
+    file_objs: Sequence[File] = []
+    if file_extra_config is None:
+        return file_objs
+    file_objs = file_factory.build_from_mappings(
+        mappings=files,
+        tenant_id=workflow.tenant_id,
+        config=file_extra_config,
+    )
+    return file_objs
+
+
 class DraftWorkflowApi(Resource):
     @setup_required
     @login_required
@@ -402,15 +424,30 @@ class DraftWorkflowNodeRunApi(Resource):
 
         parser = reqparse.RequestParser()
         parser.add_argument("inputs", type=dict, required=True, nullable=False, location="json")
+        parser.add_argument("query", type=str, required=False, location="json", default="")
+        parser.add_argument("files", type=list, location="json", default=[])
         args = parser.parse_args()
 
-        inputs = args.get("inputs")
-        if inputs == None:
+        user_inputs = args.get("inputs")
+        if user_inputs is None:
             raise ValueError("missing inputs")
 
+        workflow_srv = WorkflowService()
+        # fetch draft workflow by app_model
+        draft_workflow = workflow_srv.get_draft_workflow(app_model=app_model)
+        if not draft_workflow:
+            raise ValueError("Workflow not initialized")
+        files = _parse_file(draft_workflow, args.get("files"))
         workflow_service = WorkflowService()
+
         workflow_node_execution = workflow_service.run_draft_workflow_node(
-            app_model=app_model, node_id=node_id, user_inputs=inputs, account=current_user
+            app_model=app_model,
+            draft_workflow=draft_workflow,
+            node_id=node_id,
+            user_inputs=user_inputs,
+            account=current_user,
+            query=args.get("query", ""),
+            files=files,
         )
 
         return workflow_node_execution
@@ -731,6 +768,27 @@ class WorkflowByIdApi(Resource):
         return None, 204
 
 
+class DraftWorkflowNodeLastRunApi(Resource):
+    @setup_required
+    @login_required
+    @account_initialization_required
+    @get_app_model(mode=[AppMode.ADVANCED_CHAT, AppMode.WORKFLOW])
+    @marshal_with(workflow_run_node_execution_fields)
+    def get(self, app_model: App, node_id: str):
+        srv = WorkflowService()
+        workflow = srv.get_draft_workflow(app_model)
+        if not workflow:
+            raise NotFound("Workflow not found")
+        node_exec = srv.get_node_last_run(
+            app_model=app_model,
+            workflow=workflow,
+            node_id=node_id,
+        )
+        if node_exec is None:
+            raise NotFound("last run not found")
+        return node_exec
+
+
 api.add_resource(
     DraftWorkflowApi,
     "/apps/<uuid:app_id>/workflows/draft",
@@ -795,3 +853,7 @@ api.add_resource(
     WorkflowByIdApi,
     "/apps/<uuid:app_id>/workflows/<string:workflow_id>",
 )
+api.add_resource(
+    DraftWorkflowNodeLastRunApi,
+    "/apps/<uuid:app_id>/workflows/draft/nodes/<string:node_id>/last-run",
+)