chore(iteration): keep start_node_id using in parallel start nodes

api/core/workflow/nodes/iteration/iteration_node.py

@@ -51,40 +51,11 @@ def _run(self) -> Generator[RunEvent | InNodeEvent, None, None]:
         }
 
         graph_config = self.graph_config
+
+        if not self.node_data.start_node_id:
+            raise ValueError(f'field start_node_id in iteration {self.node_id} not found')
 
-        # find nodes in current iteration and donot have source and have have start_node_in_iteration flag
-        # these nodes are the start nodes of the iteration (in version of parallel support)
-        start_node_ids = []
-        for node_config in graph_config['nodes']:
-            if (
-                node_config.get('data', {}).get('iteration_id')
-                and node_config.get('data', {}).get('iteration_id') == self.node_id 
-                and not node_config.get('source')
-                and node_config.get('data', {}).get('start_node_in_iteration', False)
-            ):
-                start_node_ids.append(node_config.get('id'))
-
-        if len(start_node_ids) > 0:
-            # add new fake iteration start node that connect to all start nodes
-            root_node_id = f"{self.node_id}-start"
-            graph_config['nodes'].append({
-                "id": root_node_id,
-                "data": {
-                    "title": "iteration start",
-                    "type": NodeType.ITERATION_START.value,
-                }
-            })
-
-            for start_node_id in start_node_ids:
-                graph_config['edges'].append({
-                    "source": root_node_id,
-                    "target": start_node_id
-                })
-        else:
-            if not self.node_data.start_node_id:
-                raise ValueError(f'field start_node_id in iteration {self.node_id} not found')
-
-            root_node_id = self.node_data.start_node_id
+        root_node_id = self.node_data.start_node_id
 
         # init graph
         iteration_graph = Graph.init(

api/tests/unit_tests/core/workflow/nodes/iteration/test_iteration.py

@@ -214,6 +214,16 @@ def test_run_parallel():
                 "source": "iteration-1",
                 "target": "answer-3",
             },
+            {
+                "id": "iteration-start-source-tt-target",
+                "source": "iteration-start",
+                "target": "tt",
+            },
+            {
+                "id": "iteration-start-source-tt-2-target",
+                "source": "iteration-start",
+                "target": "tt-2",
+            },
             {
                 "id": "tt-source-if-else-target",
                 "source": "tt",
@@ -250,7 +260,7 @@ def test_run_parallel():
                     "output_selector": ["tt", "output"],
                     "output_type": "array[string]",
                     "startNodeType": "template-transform",
-                    "start_node_id": "tt",
+                    "start_node_id": "iteration-start",
                     "title": "iteration",
                     "type": "iteration",
                 },
@@ -268,7 +278,14 @@ def test_run_parallel():
             {
                 "data": {
                     "iteration_id": "iteration-1",
-                    "start_node_in_iteration": True,
+                    "title": "iteration-start",
+                    "type": "iteration-start",
+                },
+                "id": "iteration-start",
+            },
+            {
+                "data": {
+                    "iteration_id": "iteration-1",
                     "template": "{{ arg1 }} 123",
                     "title": "template transform",
                     "type": "template-transform",
@@ -279,7 +296,6 @@ def test_run_parallel():
             {
                 "data": {
                     "iteration_id": "iteration-1",
-                    "start_node_in_iteration": True,
                     "template": "{{ arg1 }} 321",
                     "title": "template transform",
                     "type": "template-transform",
@@ -372,6 +388,7 @@ def test_run_parallel():
                 "output_selector": ["tt", "output"],
                 "output_type": "array[string]",
                 "startNodeType": "template-transform",
+                "start_node_id": "iteration-start",
                 "title": "迭代",
                 "type": "iteration",
             },