relation: some minor changes; + __parent__ assignment for relation when registering it

git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@668 fd906abe-77d9-0310-91a1-e0d9ade77398

relation/README.txt

@@ -1,6 +1,8 @@
 Yet Another Relations (Reference) Engine...
 ===========================================
 
+  ($Id$)
+
     >>> from zope.app.testing.placelesssetup import setUp
     >>> setUp()
 
@@ -122,19 +124,31 @@ working with events).
     >>> from zope.app import zapi
     >>> relations = zapi.getUtility(IRelationsRegistry)
 
-In real life the indexes needed will be set up manually after object creation
-or via subscription to IObjectCreatedEvent - here we have to do this
-explicitly:
+In real life the indexes needed will be set up via subscription to
+IObjectCreatedEvent - here we have to do this explicitly:
 
     >>> relations.setupIndexes()
     
 In order to register relations the objects that are referenced have to be
 registered with an IntIds (unique ids) utility, so we have to set up such
-an utility (using a stub/dummy implementation for testing purposes):
+an utility (using a stub/dummy implementation for testing purposes) and
+register the objects with it (in real life this is done automatically
+when we add an object to a container):
 
     >>> from cybertools.relation.tests import IntIdsStub
     >>> from zope.app.intid.interfaces import IIntIds
     >>> ztapi.provideUtility(IIntIds, IntIdsStub())
+    >>> intids = zapi.getUtility(IIntIds)
+    >>> intids.register(clark)
+    0
+    >>> intids.register(kirk)
+    1
+    >>> intids.register(audrey)
+    2
+    >>> intids.register(washington)
+    3
+    >>> intids.register(newyork)
+    4
 
 We also have to provide an adapter for the Relation objects that provides
 the attributes needed for indexing:

relation/__init__.py

@@ -27,10 +27,19 @@ $Id$
 
 from persistent import Persistent
 from zope.interface import implements
-from interfaces import IDyadicRelation, ITriadicRelation
+from interfaces import IPredicate
+from interfaces import IRelation, IDyadicRelation, ITriadicRelation
+
+class Relation(Persistent):
+
+    implements(IPredicate, IRelation)
+
+    @classmethod
+    def getPredicateName(cls):
+        return '%s.%s' % (cls.__module__, cls.__name__)
 
 
-class DyadicRelation(Persistent):
+class DyadicRelation(Relation):
     
     implements(IDyadicRelation)
 
@@ -39,7 +48,7 @@ class DyadicRelation(Persistent):
         self.second = second
 
 
-class TriadicRelation(Persistent):
+class TriadicRelation(Relation):
     
     implements(ITriadicRelation)
 

relation/configure.zcml

@@ -63,7 +63,7 @@
       />
 
   <browser:addMenuItem
-      title="Relations Registry Utility"
+      title="Relations Registry"
       description="A utility that allows the registration of and query for relations"
       class=".registry.RelationsRegistry"
       permission="zope.ManageSite"

relation/ftests.py

@@ -30,7 +30,7 @@ class BrowserTest(FunctionalTestCase):
         browser.addHeader('Accept-Language', 'en-US')
         browser.open('http://localhost/++etc++site/default/@@contents.html')
         self.assert_(browser.isHtml)
-        addLink = browser.getLink('Relations Registry Utility')
+        addLink = browser.getLink('Relations Registry')
         addLink.click()
         self.assert_(browser.isHtml)
         inp = browser.getControl(name='new_value')

relation/interfaces.py

@@ -28,10 +28,26 @@ from zope.app.event.interfaces import IObjectEvent
 
 # relation interfaces
 
+class IPredicate(Interface):
+    """ A predicate signifies a relationship. This may be implemented
+        directly as a relation class, or the relation object may 
+        hold the predicate as an attribute.
+    """
+    
+    def getPredicateName():
+        """ Return this predicate as a string that may be used for indexing.
+        """
+        
+
 class IRelation(Interface):
     """ Base interface for relations.
     """
     
+    def getPredicateName():
+        """ Return the predicate of this relation as a string that may be
+            used for indexing.
+        """
+        
     
 class IDyadicRelation(IRelation):
     """ Relation connecting two objects.

relation/registry.py

@@ -80,18 +80,20 @@ class RelationsRegistry(Catalog):
                 self[idx] = FieldIndex(idx, IIndexableRelation)
 
     def register(self, relation):
-        #self.setupIndexes()
-        self.index_doc(_getUid(relation), relation)
+        if getattr(relation, '__parent__', None) is None:
+            # Allow the IntIds utility to get a DB connection:
+            relation.__parent__ = self
+        self.index_doc(zapi.getUtility(IIntIds).register(relation), relation)
     
     def unregister(self, relation):
-        self.unindex_doc(_getUid(relation))
+        self.unindex_doc(zapi.getUtility(IIntIds).getId(relation))
     
     def query(self, **kw):
         for k in kw:
             if k == 'relationship':
-                quString = _getClassString(kw[k])
+                quString = kw[k].getPredicateName()
             else:
-                quString = _getUid(kw[k])
+                quString = zapi.getUtility(IIntIds).getId(kw[k])
             # set min, max
             kw[k] = (quString, quString)
         return self.searchResults(**kw)
@@ -115,29 +117,17 @@ class IndexableRelationAdapter(object):
         self.context = context
 
     def getRelationship(self):
-        return _getRelationship(self.context)
+        return self.context.getPredicateName()
     relationship = property(getRelationship)
 
     def __getattr__(self, attr):
         value = getattr(self.context, attr)
         if isinstance(value, Persistent):
-            return _getUid(value)
+            return zapi.getUtility(IIntIds).getId(value)
         else:
             return value
 
 
-# helper functions
-        
-def _getUid(ob):
-    return zapi.getUtility(IIntIds).getId(ob)
-
-def _getRelationship(relation):
-    return _getClassString(removeSecurityProxy(relation).__class__)
-
-def _getClassString(cls):
-    return '%s.%s' % (cls.__module__, cls.__name__)
-
-
 # events and handlers
 
 class RelationInvalidatedEvent(ObjectEvent):

relation/tests.py

@@ -9,7 +9,8 @@ from zope.app import zapi
 from zope.app.intid.interfaces import IIntIds
 
 from cybertools.relation.interfaces import IDyadicRelation, ITriadicRelation
-from cybertools.relation import DyadicRelation, TriadicRelation
+from cybertools.relation.interfaces import IRelation, IPredicate
+from cybertools.relation import Relation, DyadicRelation, TriadicRelation
 from cybertools.relation.interfaces import IRelationsRegistry
 from cybertools.relation.registry import RelationsRegistry
 
@@ -25,6 +26,9 @@ class IntIdsStub:
         return self.objs[uid]
 
     def getId(self, ob):
+        return self.objs.index(ob)
+
+    def register(self, ob):
         if ob not in self.objs:
             self.objs.append(ob)
         return self.objs.index(ob)
@@ -38,6 +42,8 @@ class TestRelation(unittest.TestCase):
     "Basic tests for the relation package."
 
     def testInterfaces(self):
+        verifyClass(IPredicate, Relation)
+        verifyClass(IRelation, Relation)
         self.assert_(IDyadicRelation.providedBy(DyadicRelation(None, None)),
             'Interface IDyadicRelation is not implemented by class DyadicRelation.')
         verifyClass(IDyadicRelation, DyadicRelation)