fix(graph_engine): Cannot run single iteration or loop node

Signed-off-by: -LAN- <laipz8200@outlook.com>

api/core/app/apps/workflow_app_runner.py

@@ -157,7 +157,7 @@ class WorkflowBasedAppRunner:
         # Create initial runtime state with variable pool containing environment variables
         graph_runtime_state = GraphRuntimeState(
             variable_pool=VariablePool(
-                system_variables=SystemVariable.empty(),
+                system_variables=SystemVariable.default(),
                 user_inputs={},
                 environment_variables=workflow.environment_variables,
             ),
@@ -268,7 +268,9 @@ class WorkflowBasedAppRunner:
         )
 
         # init graph
-        graph = Graph.init(graph_config=graph_config, node_factory=node_factory, root_node_id=node_id)
+        graph = Graph.init(
+            graph_config=graph_config, node_factory=node_factory, root_node_id=node_id, skip_validation=True
+        )
 
         if not graph:
             raise ValueError("graph not found in workflow")

api/core/workflow/graph/graph.py

@@ -288,6 +288,7 @@ class Graph:
         graph_config: Mapping[str, object],
         node_factory: NodeFactory,
         root_node_id: str | None = None,
+        skip_validation: bool = False,
     ) -> Graph:
         """
         Initialize graph
@@ -339,8 +340,9 @@ class Graph:
             root_node=root_node,
         )
 
-        # Validate the graph structure using built-in validators
-        get_graph_validator().validate(graph)
+        if not skip_validation:
+            # Validate the graph structure using built-in validators
+            get_graph_validator().validate(graph)
 
         return graph
 

api/core/workflow/runtime/variable_pool.py

@@ -44,7 +44,7 @@ class VariablePool(BaseModel):
     )
     system_variables: SystemVariable = Field(
         description="System variables",
-        default_factory=SystemVariable.empty,
+        default_factory=SystemVariable.default,
     )
     environment_variables: Sequence[Variable] = Field(
         description="Environment variables.",
@@ -271,4 +271,4 @@ class VariablePool(BaseModel):
     @classmethod
     def empty(cls) -> VariablePool:
         """Create an empty variable pool."""
-        return cls(system_variables=SystemVariable.empty())
+        return cls(system_variables=SystemVariable.default())

api/core/workflow/system_variable.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 from collections.abc import Mapping, Sequence
 from types import MappingProxyType
 from typing import Any
+from uuid import uuid4
 
 from pydantic import AliasChoices, BaseModel, ConfigDict, Field, model_validator
 
@@ -72,8 +73,8 @@ class SystemVariable(BaseModel):
         return data
 
     @classmethod
-    def empty(cls) -> SystemVariable:
-        return cls()
+    def default(cls) -> SystemVariable:
+        return cls(workflow_execution_id=str(uuid4()))
 
     def to_dict(self) -> dict[SystemVariableKey, Any]:
         # NOTE: This method is provided for compatibility with legacy code.

api/core/workflow/workflow_entry.py

@@ -276,7 +276,7 @@ class WorkflowEntry:
 
         # init variable pool
         variable_pool = VariablePool(
-            system_variables=SystemVariable.empty(),
+            system_variables=SystemVariable.default(),
             user_inputs={},
             environment_variables=[],
         )