feat(workflow): support retrieving variables wrapped in {{}} from variable pool

api/app/core/workflow/variable_pool.py

@@ -10,6 +10,7 @@
 """
 
 import logging
+import re
 from typing import Any, TYPE_CHECKING
 
 if TYPE_CHECKING:
@@ -28,7 +29,7 @@ class VariableSelector:
         >>> selector = VariableSelector(["node_A", "output"])
         >>> selector = VariableSelector.from_string("sys.message")
     """
-    
+
     def __init__(self, path: list[str]):
         """初始化变量选择器
         
@@ -37,11 +38,11 @@ class VariableSelector:
         """
         if not path or len(path) < 1:
             raise ValueError("变量路径不能为空")
-        
+
         self.path = path
         self.namespace = path[0]  # sys, var, 或 node_id
         self.key = path[1] if len(path) > 1 else None
-    
+
     @classmethod
     def from_string(cls, selector_str: str) -> "VariableSelector":
         """从字符串创建选择器
@@ -58,10 +59,10 @@ class VariableSelector:
         """
         path = selector_str.split(".")
         return cls(path)
-    
+
     def __str__(self) -> str:
         return ".".join(self.path)
-    
+
     def __repr__(self) -> str:
         return f"VariableSelector({self.path})"
 
@@ -84,7 +85,7 @@ class VariablePool:
         "AI 的回答"
         >>> pool.set(["conv", "user_name"], "张三")
     """
-    
+
     def __init__(self, state: "WorkflowState"):
         """初始化变量池
         
@@ -92,7 +93,7 @@ class VariablePool:
             state: 工作流状态（LangGraph State）
         """
         self.state = state
-    
+
     def get(self, selector: list[str] | str, default: Any = None) -> Any:
         """获取变量值
         
@@ -114,13 +115,15 @@ class VariablePool:
         """
         # 转换为 VariableSelector
         if isinstance(selector, str):
-            selector = VariableSelector.from_string(selector).path
-        
+            pattern = r"\{\{\s*(.*?)\s*\}\}"
+            variable_literal = re.sub(pattern, r"\1", selector).strip()
+            selector = VariableSelector.from_string(variable_literal).path
+
         if not selector or len(selector) < 1:
             raise ValueError("变量选择器不能为空")
-        
+
         namespace = selector[0]
-        
+
         try:
             # 系统变量
             if namespace == "sys":
@@ -128,30 +131,30 @@ class VariablePool:
                 if not key:
                     return self.state.get("variables", {}).get("sys", {})
                 return self.state.get("variables", {}).get("sys", {}).get(key, default)
-            
+
             # 会话变量
             elif namespace == "conv":
                 key = selector[1] if len(selector) > 1 else None
                 if not key:
                     return self.state.get("variables", {}).get("conv", {})
                 return self.state.get("variables", {}).get("conv", {}).get(key, default)
-            
+
             # 节点输出（从 runtime_vars 读取）
             else:
                 node_id = namespace
                 runtime_vars = self.state.get("runtime_vars", {})
-                
+
                 if node_id not in runtime_vars:
                     if default is not None:
                         return default
                     raise KeyError(f"节点 '{node_id}' 的输出不存在")
-                
+
                 node_var = runtime_vars[node_id]
-                
+
                 # 如果只有节点 ID，返回整个变量
                 if len(selector) == 1:
                     return node_var
-                
+
                 # 获取特定字段
                 # 支持嵌套访问，如 node_id.field.subfield
                 result = node_var
@@ -166,14 +169,14 @@ class VariablePool:
                         if default is not None:
                             return default
                         raise KeyError(f"无法访问 '{'.'.join(selector)}'")
-                
+
                 return result
-        
+
         except KeyError:
             if default is not None:
                 return default
             raise
-    
+
     def set(self, selector: list[str] | str, value: Any):
         """设置变量值
         
@@ -192,17 +195,17 @@ class VariablePool:
         # 转换为 VariableSelector
         if isinstance(selector, str):
             selector = VariableSelector.from_string(selector).path
-        
+
         if not selector or len(selector) < 2:
             raise ValueError("变量选择器必须包含命名空间和键名")
-        
+
         namespace = selector[0]
-        
+
         if namespace != "conv" and namespace not in self.state["cycle_nodes"]:
             raise ValueError("Only conversation or cycle variables can be assigned.")
-        
+
         key = selector[1]
-        
+
         # 确保 variables 结构存在
         if "variables" not in self.state:
             self.state["variables"] = {"sys": {}, "conv": {}}
@@ -214,9 +217,9 @@ class VariablePool:
             self.state["variables"]["conv"][key] = value
         elif namespace in self.state["cycle_nodes"]:
             self.state["runtime_vars"][namespace][key] = value
-        
+
         logger.debug(f"设置变量: {'.'.join(selector)} = {value}")
-    
+
     def has(self, selector: list[str] | str) -> bool:
         """检查变量是否存在
         
@@ -237,7 +240,7 @@ class VariablePool:
             return True
         except KeyError:
             return False
-    
+
     def get_all_system_vars(self) -> dict[str, Any]:
         """获取所有系统变量
         
@@ -245,7 +248,7 @@ class VariablePool:
             系统变量字典
         """
         return self.state.get("variables", {}).get("sys", {})
-    
+
     def get_all_conversation_vars(self) -> dict[str, Any]:
         """获取所有会话变量
         
@@ -253,7 +256,7 @@ class VariablePool:
             会话变量字典
         """
         return self.state.get("variables", {}).get("conv", {})
-    
+
     def get_all_node_outputs(self) -> dict[str, Any]:
         """获取所有节点输出（运行时变量）
         
@@ -261,7 +264,7 @@ class VariablePool:
             节点输出字典，键为节点 ID
         """
         return self.state.get("runtime_vars", {})
-    
+
     def get_node_output(self, node_id: str) -> dict[str, Any] | None:
         """获取指定节点的输出（运行时变量）
         
@@ -272,7 +275,7 @@ class VariablePool:
             节点输出或 None
         """
         return self.state.get("runtime_vars", {}).get(node_id)
-    
+
     def to_dict(self) -> dict[str, Any]:
         """导出为字典
         
@@ -284,12 +287,12 @@ class VariablePool:
             "conversation": self.get_all_conversation_vars(),
             "nodes": self.get_all_node_outputs()  # 从 runtime_vars 读取
         }
-    
+
     def __repr__(self) -> str:
         sys_vars = self.get_all_system_vars()
         conv_vars = self.get_all_conversation_vars()
         runtime_vars = self.get_all_node_outputs()
-        
+
         return (
             f"VariablePool(\n"
             f"  system_vars={len(sys_vars)},\n"