meta_type of the form 'ERP5 ' + portal_type_name to portal type classes

This allows us to delay even more the point when Zope forcibly unghosts
objects.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@42398 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/dynamic/lazy_class.py

@@ -50,6 +50,8 @@ class GhostBaseMetaClass(ExtensionClass):
       Because __bases__ is changed, the behavior of this object
       will change after the first call.
       """
+      if attr == 'meta_type':
+        return cls.meta_type
       # Class must be loaded if '__of__' is requested because otherwise,
       # next call to __getattribute__ would lose any acquisition wrapper.
       if attr in ('__class__',
@@ -154,6 +156,7 @@ class PortalTypeMetaClass(GhostBaseMetaClass):
         if attr not in ('__module__',
                         '__doc__',
                         '__isghost__',
+                        'meta_type',
                         'portal_type'):
           delattr(cls, attr)
       # generate a ghostbase that derives from all previous bases
@@ -229,4 +232,5 @@ class PortalTypeMetaClass(GhostBaseMetaClass):
 def generateLazyPortalTypeClass(portal_type_name):
   return PortalTypeMetaClass(portal_type_name,
                              (InitGhostBase,),
-                             dict(portal_type=portal_type_name))
+                             dict(portal_type=portal_type_name,
+                                  meta_type='ERP5 %s' % portal_type_name))