IView.target attribute: implement with 1:n relation

git-svn-id: svn://svn.cy55.de/Zope3/src/loops/trunk@954 fd906abe-77d9-0310-91a1-e0d9ade77398

README.txt

@@ -107,7 +107,7 @@ We first need a view manager:
   >>> views = loops['views']
 
 The view space is typically built up with nodes; a node may be a top-level
-menu that may contain other nodes as menu items:
+menu that may contain other nodes as menu or content items:
       
   >>> m1 = Node(u'Menu')
   >>> views['m1'] = m1
@@ -126,5 +126,12 @@ We can associate a node with a concept or directly with a resource via the
 view class's target attribute:
 
   >>> m111.target = zope_info
-  >>> m112.target = zope3
+  >>> m111.target is zope_info
+  True
+  >>> m111.target = zope_info
+  >>> m111.target is zope_info
+  True
+  >>> m111.target = zope3
+  >>> m111.target is zope3
+  True
 

configure.zcml

@@ -166,9 +166,9 @@
         permission="zope.ManageContent"
         set_schema=".interfaces.INode" />
 
-    <require
+    <!--<require
         permission="zope.View"
-        interface="zope.app.container.interfaces.IReadContainer" />
+        interface="zope.app.container.interfaces.IReadContainer" />-->
 
   </content>
 

interfaces.py

@@ -26,7 +26,7 @@ from zope.interface import Interface, Attribute
 from zope.i18nmessageid import MessageFactory
 from zope import schema
 from zope.app.container.constraints import contains, containers
-from zope.app.container.interfaces import IContainer
+from zope.app.container.interfaces import IContainer, IOrderedContainer
 from zope.app.file.interfaces import IFile as IBaseFile
 from zope.app.folder.interfaces import IFolder
 
@@ -153,7 +153,7 @@ class IResourceManagerContained(Interface):
 
 class IView(Interface):
     """ A view is a user interface component that provides access to one
-        or more concepts.
+        or more concepts, resources, or other views.
     """
 
     title = schema.TextLine(
@@ -171,7 +171,7 @@ class IView(Interface):
     target = Attribute('Target object that is referenced by this view')
     
 
-class INode(IView):
+class INode(IView, IOrderedContainer):
     """ A node is a view that may contain other views, thus building a
         menu or folder hierarchy.
     """

view.py

@@ -51,23 +51,24 @@ class View(object):
     description = property(getDescription, setDescription)
 
     def getTarget(self):
-        rels = getRelations(first=self)
+        rels = getRelations(first=self, relationships=[TargetRelation])
         if len(rels) == 0:
             return None
         if len(rels) > 1:
             raise ValueError, 'There may be only one target for a View object.'
-        return rels.next().second
+        return list(rels)[0].second
 
     def setTarget(self, target):
-        return
         registry = zapi.getUtility(IRelationsRegistry)
-        rels = registry.query(first=self)
+        rels = list(registry.query(first=self, relationship=TargetRelation))
         if len(rels) > 0:
-            if rels[0].second != target:
-                registry.unregister(target)
-        else:
-            rel = relationship(self, concept)
-            registry.register(rel)
+            oldRel = rels[0]
+            if oldRel.second is target:
+                return
+            else:
+                registry.unregister(oldRel)
+        rel = TargetRelation(self, target)
+        registry.register(rel)
 
     target = property(getTarget, setTarget)