feat: add agent strategy on node start (#12667)

Co-authored-by: Novice Lee <novicelee@NoviPro.local>

api/core/app/apps/workflow_app_runner.py

@@ -241,6 +241,7 @@ class WorkflowBasedAppRunner(AppRunner):
                     predecessor_node_id=event.predecessor_node_id,
                     in_iteration_id=event.in_iteration_id,
                     parallel_mode_run_id=event.parallel_mode_run_id,
+                    agent_strategy=event.agent_strategy,
                 )
             )
         elif isinstance(event, NodeRunSucceededEvent):

api/core/app/entities/queue_entities.py

@@ -6,7 +6,7 @@ from typing import Any, Optional
 from pydantic import BaseModel
 
 from core.model_runtime.entities.llm_entities import LLMResult, LLMResultChunk
-from core.workflow.entities.node_entities import NodeRunMetadataKey
+from core.workflow.entities.node_entities import AgentNodeStrategyInit, NodeRunMetadataKey
 from core.workflow.graph_engine.entities.graph_runtime_state import GraphRuntimeState
 from core.workflow.nodes import NodeType
 from core.workflow.nodes.base import BaseNodeData
@@ -281,6 +281,7 @@ class QueueNodeStartedEvent(AppQueueEvent):
     start_at: datetime
     parallel_mode_run_id: Optional[str] = None
     """iteratoin run in parallel mode run id"""
+    agent_strategy: Optional[AgentNodeStrategyInit] = None
 
 
 class QueueNodeSucceededEvent(AppQueueEvent):

api/core/app/entities/task_entities.py

@@ -6,6 +6,7 @@ from pydantic import BaseModel, ConfigDict
 
 from core.model_runtime.entities.llm_entities import LLMResult
 from core.model_runtime.utils.encoders import jsonable_encoder
+from core.workflow.entities.node_entities import AgentNodeStrategyInit
 from models.workflow import WorkflowNodeExecutionStatus
 
 
@@ -248,6 +249,7 @@ class NodeStartStreamResponse(StreamResponse):
         parent_parallel_start_node_id: Optional[str] = None
         iteration_id: Optional[str] = None
         parallel_run_id: Optional[str] = None
+        agent_strategy: Optional[AgentNodeStrategyInit] = None
 
     event: StreamEvent = StreamEvent.NODE_STARTED
     workflow_run_id: str

api/core/app/task_pipeline/workflow_cycle_manage.py

@@ -541,6 +541,7 @@ class WorkflowCycleManage:
                 parent_parallel_start_node_id=event.parent_parallel_start_node_id,
                 iteration_id=event.in_iteration_id,
                 parallel_run_id=event.parallel_mode_run_id,
+                agent_strategy=event.agent_strategy,
             ),
         )
 

api/core/workflow/entities/node_entities.py

@@ -49,3 +49,8 @@ class NodeRunResult(BaseModel):
 
     # single step node run retry
     retry_index: int = 0
+
+
+class AgentNodeStrategyInit(BaseModel):
+    name: str
+    icon: str | None = None

api/core/workflow/graph_engine/entities/event.py

@@ -4,6 +4,7 @@ from typing import Any, Optional
 
 from pydantic import BaseModel, Field
 
+from core.workflow.entities.node_entities import AgentNodeStrategyInit
 from core.workflow.graph_engine.entities.runtime_route_state import RouteNodeState
 from core.workflow.nodes import NodeType
 from core.workflow.nodes.base import BaseNodeData
@@ -66,8 +67,10 @@ class BaseNodeEvent(GraphEngineEvent):
 
 class NodeRunStartedEvent(BaseNodeEvent):
     predecessor_node_id: Optional[str] = None
-    parallel_mode_run_id: Optional[str] = None
     """predecessor node id"""
+    parallel_mode_run_id: Optional[str] = None
+    """iteration node parallel mode run id"""
+    agent_strategy: Optional[AgentNodeStrategyInit] = None
 
 
 class NodeRunStreamChunkEvent(BaseNodeEvent):

api/core/workflow/graph_engine/graph_engine.py

@@ -14,7 +14,7 @@ from flask import Flask, current_app
 from configs import dify_config
 from core.app.apps.base_app_queue_manager import GenerateTaskStoppedError
 from core.app.entities.app_invoke_entities import InvokeFrom
-from core.workflow.entities.node_entities import NodeRunMetadataKey, NodeRunResult
+from core.workflow.entities.node_entities import AgentNodeStrategyInit, NodeRunMetadataKey, NodeRunResult
 from core.workflow.entities.variable_pool import VariablePool, VariableValue
 from core.workflow.graph_engine.condition_handlers.condition_manager import ConditionManager
 from core.workflow.graph_engine.entities.event import (
@@ -40,6 +40,8 @@ from core.workflow.graph_engine.entities.graph_init_params import GraphInitParam
 from core.workflow.graph_engine.entities.graph_runtime_state import GraphRuntimeState
 from core.workflow.graph_engine.entities.runtime_route_state import RouteNodeState
 from core.workflow.nodes import NodeType
+from core.workflow.nodes.agent.agent_node import AgentNode
+from core.workflow.nodes.agent.entities import AgentNodeData
 from core.workflow.nodes.answer.answer_stream_processor import AnswerStreamProcessor
 from core.workflow.nodes.answer.base_stream_processor import StreamProcessor
 from core.workflow.nodes.base import BaseNode
@@ -606,6 +608,14 @@ class GraphEngine:
         Run node
         """
         # trigger node run start event
+        agent_strategy = (
+            AgentNodeStrategyInit(
+                name=cast(AgentNodeData, node_instance.node_data).agent_strategy_name,
+                icon=cast(AgentNode, node_instance).agent_strategy_icon,
+            )
+            if node_instance.node_type == NodeType.AGENT
+            else None
+        )
         yield NodeRunStartedEvent(
             id=node_instance.id,
             node_id=node_instance.node_id,
@@ -617,6 +627,7 @@ class GraphEngine:
             parallel_start_node_id=parallel_start_node_id,
             parent_parallel_id=parent_parallel_id,
             parent_parallel_start_node_id=parent_parallel_start_node_id,
+            agent_strategy=agent_strategy,
         )
 
         db.session.close()

api/core/workflow/nodes/agent/agent_node.py

@@ -90,18 +90,11 @@ class AgentNode(ToolNode):
 
         try:
             # convert tool messages
-            manager = PluginInstallationManager()
+
-            plugins = manager.list_plugins(self.tenant_id)
-            current_plugin = next(
-                plugin
-                for plugin in plugins
-                if f"{plugin.plugin_id}/{plugin.name}"
-                == cast(AgentNodeData, self.node_data).agent_strategy_provider_name
-            )
             yield from self._transform_message(
                 message_stream,
                 {
-                    "icon": current_plugin.declaration.icon,
+                    "icon": self.agent_strategy_icon,
                     "agent_strategy": cast(AgentNodeData, self.node_data).agent_strategy_name,
                 },
                 parameters_for_log,
@@ -229,16 +222,33 @@ class AgentNode(ToolNode):
         result: dict[str, Any] = {}
         for parameter_name in node_data.agent_parameters:
             input = node_data.agent_parameters[parameter_name]
-            if input.type == "mixed":
+            if input.type in ["mixed", "constant"]:
-                assert isinstance(input.value, str)
+                selectors = VariableTemplateParser(str(input.value)).extract_variable_selectors()
-                selectors = VariableTemplateParser(input.value).extract_variable_selectors()
                 for selector in selectors:
                     result[selector.variable] = selector.value_selector
             elif input.type == "variable":
                 result[parameter_name] = input.value
-            elif input.type == "constant":
-                pass
 
         result = {node_id + "." + key: value for key, value in result.items()}
 
         return result
+
+    @property
+    def agent_strategy_icon(self) -> str | None:
+        """
+        Get agent strategy icon
+        :return:
+        """
+        manager = PluginInstallationManager()
+        plugins = manager.list_plugins(self.tenant_id)
+        try:
+            current_plugin = next(
+                plugin
+                for plugin in plugins
+                if f"{plugin.plugin_id}/{plugin.name}"
+                == cast(AgentNodeData, self.node_data).agent_strategy_provider_name
+            )
+            icon = current_plugin.declaration.icon
+        except StopIteration:
+            icon = None
+        return icon