- improvement to scoping of "caller" variable when using <%call> tag

2 files changed, 27 insertions, 6 deletions

diff --git a/lib/mako/codegen.py b/lib/mako/codegen.py
index 477ccad..285e392 100644
--- a/lib/mako/codegen.py
+++ b/lib/mako/codegen.py
@@ -523,14 +523,15 @@ class _GenerateRenderMethod(object):
 
         self.printer.writelines(
             # push on global "caller" to be picked up by the next ccall
-            "context.caller_stack.append(runtime.Namespace('caller', context, callables=ccall(context.caller_stack[-1])))",
+            "caller = context['caller']._get_actual_caller()",
+            "context.push_caller(runtime.Namespace('caller', context, callables=ccall(runtime._StackFacade(context, caller))))",
             "try:")
         self.write_source_comment(node)
         self.printer.writelines(
                 "context.write(unicode(%s))" % node.attributes['expr'],
             "finally:",
                 # pop it off
-                "context.caller_stack.pop()",
+                "context.pop_caller()",
             None
         )
 
diff --git a/lib/mako/runtime.py b/lib/mako/runtime.py
index 20748b9..e6e640b 100644
--- a/lib/mako/runtime.py
+++ b/lib/mako/runtime.py
@@ -23,9 +23,13 @@ class Context(object):
         
         # "caller" stack used by def calls with content
         self.caller_stack = [Undefined]
-        data['caller'] = _StackFacade(self.caller_stack)
+        data['caller'] = _StackFacade(self, None)
     lookup = property(lambda self:self._with_template.lookup)
     kwargs = property(lambda self:self._kwargs.copy())
+    def push_caller(self, caller):
+        self.caller_stack.append(caller)
+    def pop_caller(self):
+        del self.caller_stack[-1]
     def keys(self):
         return self._data.keys()
     def __getitem__(self, key):
@@ -67,10 +71,26 @@ class Context(object):
         return c
 
 class _StackFacade(object):
-    def __init__(self, stack):
-        self.target = stack
+    def __init__(self, context, local):
+        self.__stack = context.caller_stack
+        self.__local = local
+    def _get_actual_caller(self):
+        caller = self.__stack[-1]
+        if caller is None:
+            return self.__local
+        else:
+            return caller
     def __getattr__(self, key):
-        return getattr(self.target[-1], key)
+        caller = self._get_actual_caller()
+        callable_ = getattr(caller, key)
+        def call_wno_caller(*args, **kwargs):
+            try:
+                self.__stack.append(None)
+                return callable_(*args, **kwargs)
+            finally:
+                self.__stack.pop()
+        return call_wno_caller
+        
         
 class Undefined(object):
     """represents an undefined value in a template."""