Performance improvement in XML marshaller by mimicking StringIO in unicode-friendly buffer UnicodeBuffer and added a class appy.gen.No allowing to explain why some workflow condition cannot be triggered.

gen/__init__.py

@@ -581,6 +581,17 @@ class Permission:
 class ReadPermission(Permission): pass
 class WritePermission(Permission): pass
 
+class No:
+    '''When you write a workflow condition method and you want to return False
+       but you want to give to the user some explanations about why a transition
+       can't be triggered, do not return False, return an instance of No
+       instead. When creating such an instance, you can specify an error
+       message.'''
+    def __init__(self, msg):
+        self.msg = msg
+    def __nonzero__(self):
+        return False
+
 # ------------------------------------------------------------------------------
 class Selection:
     '''Instances of this class may be given as validator of a String, in order

gen/plone25/mixins/PodTemplateMixin.py

@@ -3,6 +3,8 @@ import os, os.path, time, unicodedata
 from appy.shared import mimeTypes
 from appy.gen.plone25.mixins import AbstractMixin
 from StringIO import StringIO
+import appy.pod
+from appy.pod.renderer import Renderer
 
 # ------------------------------------------------------------------------------
 class PodError(Exception): pass
@@ -81,8 +83,6 @@ class PodTemplateMixin(AbstractMixin):
         if appySelf.tool.openOfficePort:
             rendererParams['ooPort'] = appySelf.tool.openOfficePort
         # Launch the renderer
-        import appy.pod
-        from appy.pod.renderer import Renderer
         try:
             renderer = Renderer(**rendererParams)
             renderer.run()