Move some policy out of the conversation storage adapter into a view,

specifically "enabled()".  Prevents having to replace/migrate
persistent objects to change policy which really only concerns the
context and possibly the request, not the conversation storage. Fixes
#11372.

svn path=/plone.app.discussion/trunk/; revision=48849

plone/app/discussion/conversation.py

@@ -14,10 +14,9 @@ import time
 
 from persistent import Persistent
 
-from plone.registry.interfaces import IRegistry
-
 from zope.interface import implements, implementer
-from zope.component import adapts, adapter, queryUtility
+from zope.component import adapts
+from zope.component import adapter
 
 from zope.annotation.interfaces import IAnnotations, IAnnotatable
 
@@ -31,11 +30,6 @@ from OFS.Traversable import Traversable
 from OFS.event import ObjectWillBeAddedEvent
 from OFS.event import ObjectWillBeRemovedEvent
 
-from Products.CMFCore.utils import getToolByName
-from Products.CMFCore.interfaces import IFolderish
-
-from Products.CMFPlone.interfaces import IPloneSiteRoot, INonStructuralFolder
-
 from zope.container.contained import ContainerModifiedEvent
 
 from zope.lifecycleevent import ObjectCreatedEvent
@@ -49,7 +43,6 @@ from BTrees.LOBTree import LOBTree
 from BTrees.LLBTree import LLSet
 
 from plone.app.discussion.interfaces import IConversation
-from plone.app.discussion.interfaces import IDiscussionSettings
 from plone.app.discussion.interfaces import IReplies
 from plone.app.discussion.comment import Comment
 
@@ -87,63 +80,8 @@ class Conversation(Traversable, Persistent, Explicit):
         return self.id
 
     def enabled(self):
-        # Returns True if discussion is enabled on the conversation
-
-        # Fetch discussion registry
-        registry = queryUtility(IRegistry)
-        settings = registry.forInterface(IDiscussionSettings, check=False)
-
-        # Check if discussion is allowed globally
-        if not settings.globally_enabled:
-            return False
-
         parent = aq_inner(self.__parent__)
-
-        # Always return False if object is a folder
-        if (IFolderish.providedBy(parent) and
-            not INonStructuralFolder.providedBy(parent)):
-            return False
-
-        def traverse_parents(obj):
-            # Run through the aq_chain of obj and check if discussion is
-            # enabled in a parent folder.
-            for obj in self.aq_chain:
-                if not IPloneSiteRoot.providedBy(obj):
-                    if (IFolderish.providedBy(obj) and
-                        not INonStructuralFolder.providedBy(obj)):
-                        flag = getattr(obj, 'allow_discussion', None)
-                        if flag is not None:
-                            return flag
-            return None
-
-        obj = aq_parent(self)
-
-        # If discussion is disabled for the object, bail out
-        obj_flag = getattr(aq_base(obj), 'allow_discussion', None)
-        if obj_flag is False:
-            return False
-
-        # Check if traversal returned a folder with discussion_allowed set
-        # to True or False.
-        folder_allow_discussion = traverse_parents(obj)
-
-        if folder_allow_discussion is True:
-            if not getattr(self, 'allow_discussion', None):
-                return True
-        elif folder_allow_discussion is False:
-            if obj_flag:
-                return True
-
-        # Check if discussion is allowed on the content type
-        portal_types = getToolByName(self, 'portal_types')
-        document_fti = getattr(portal_types, obj.portal_type)
-        if not document_fti.getProperty('allow_discussion'):
-            # If discussion is not allowed on the content type,
-            # check if 'allow discussion' is overridden on the content object.
-            if not obj_flag:
-                return False
-
-        return True
+        return parent.restrictedTraverse('@@conversation_view').enabled()
 
     @property
     def total_comments(self):