Refactor form update handling in API endpoints and models

- Introduced a new function to parse JSON values in endpoints.py for improved data handling.
- Updated extract_form_update_from_flow_nodes to return structured data instead of strings.
- Changed formUpdate field in ProcessResponse_chat model to use Any type with a default empty dictionary for better flexibility in handling updates.

src/api/endpoints.py

@@ -71,10 +71,26 @@ def extract_state_and_content(data1: str) -> dict | None:
     return None
 
 
-def extract_form_update_from_flow_nodes(nodes) -> str:
+def parse_json_value(value):
+    """Parse JSON string values when possible."""
+    parsed = value
+    for _ in range(3):
+        if not isinstance(parsed, str):
+            return parsed
+        parsed = parsed.strip()
+        if not parsed:
+            return {}
+        try:
+            parsed = json.loads(parsed)
+        except json.JSONDecodeError:
+            return parsed
+    return parsed
+
+
+def extract_form_update_from_flow_nodes(nodes):
     """Extract form update data from the configured FastGPT content-extract node."""
     if not isinstance(nodes, list):
-        return ""
+        return {}
 
     for node in nodes:
         if not isinstance(node, dict):
@@ -84,16 +100,14 @@ def extract_form_update_from_flow_nodes(nodes) -> str:
 
         extract_result = node.get("extractResult", {})
         if not isinstance(extract_result, dict):
-            return ""
+            return {}
 
-        form_update = extract_result.get("formUpdate", "")
+        form_update = extract_result.get("formUpdate") or extract_result.get("form") or ""
-        if isinstance(form_update, str):
+        if not form_update:
-            return form_update
+            return {}
-        if form_update:
+        return parse_json_value(form_update)
-            return json.dumps(form_update, ensure_ascii=False)
-        return ""
 
-    return ""
+    return {}
 
 
 def format_set_info_input(payload: dict, include_input_info: bool) -> str:
@@ -180,8 +194,8 @@ async def chat(
                 def flush_text_delta(text: str):
                     return create_sse_event("text_delta", {"text": text})
 
-                def flush_form_update(form_update: str):
+                def flush_form_update(form_update):
-                    return create_sse_event("formUpdate", {"formUpdate": form_update})
+                    return create_sse_event("formUpdate", form_update)
                 
                 async for event in aiter_stream_events(response):
                     try:

src/schemas/models.py

@@ -1,5 +1,5 @@
 from pydantic import BaseModel, Field
-from typing import Optional
+from typing import Any, Optional
 
 class ProcessRequest_chat(BaseModel):
     sessionId: str = Field(..., max_length=64)
@@ -11,7 +11,7 @@ class ProcessResponse_chat(BaseModel):
     sessionId: str = Field(..., max_length=64)
     timeStamp: str = Field(..., max_length=32)
     outputText: str = Field(...)
-    formUpdate: str = Field(default="")
+    formUpdate: Any = Field(default_factory=dict)
     nextStage: str = Field(..., max_length=32)
     nextStageCode: str = Field(..., max_length=4)
     code: str = Field(..., max_length=4)