support returning structured output when using LLM API non streaming invocation (#26451)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

api/core/workflow/node_events/node.py

@@ -20,6 +20,7 @@ class ModelInvokeCompletedEvent(NodeEventBase):
     usage: LLMUsage
     finish_reason: str | None = None
     reasoning_content: str | None = None
+    structured_output: dict | None = None
 
 
 class RunRetryEvent(NodeEventBase):

api/core/workflow/nodes/llm/node.py

@@ -23,6 +23,7 @@ from core.model_runtime.entities.llm_entities import (
     LLMResult,
     LLMResultChunk,
     LLMResultChunkWithStructuredOutput,
+    LLMResultWithStructuredOutput,
     LLMStructuredOutput,
     LLMUsage,
 )
@@ -278,6 +279,13 @@ class LLMNode(Node):
                         # Extract clean text from <think> tags
                         clean_text, _ = LLMNode._split_reasoning(result_text, self._node_data.reasoning_format)
 
+                    # Process structured output if available from the event.
+                    structured_output = (
+                        LLMStructuredOutput(structured_output=event.structured_output)
+                        if event.structured_output
+                        else None
+                    )
+
                     # deduct quota
                     llm_utils.deduct_llm_quota(tenant_id=self.tenant_id, model_instance=model_instance, usage=usage)
                     break
@@ -1048,7 +1056,7 @@ class LLMNode(Node):
     @staticmethod
     def handle_blocking_result(
         *,
-        invoke_result: LLMResult,
+        invoke_result: LLMResult | LLMResultWithStructuredOutput,
         saver: LLMFileSaver,
         file_outputs: list["File"],
         reasoning_format: Literal["separated", "tagged"] = "tagged",
@@ -1079,6 +1087,8 @@ class LLMNode(Node):
             finish_reason=None,
             # Reasoning content for workflow variables and downstream nodes
             reasoning_content=reasoning_content,
+            # Pass structured output if enabled
+            structured_output=getattr(invoke_result, "structured_output", None),
         )
 
     @staticmethod