work in progress: rels

scopes/interfaces.py

@@ -24,17 +24,6 @@ class IContainer(ITraversable):
         and the value object (e.g. `parent´ and `name`) are stored correctly."""
 
 
-class IConcept(IContainer):
-
-    def parents(*predicates):
-        """Return a sequence of `Triple`s in which this object is 
-           referenced as `second`."""
-
-    def children(*predicates):
-        """Return a sequence of `Triple`s in which this object is 
-           referenced as `first`."""
-
-
 class IView(Interface):
 
     def __call__():

scopes/storage/concept.py

@@ -3,23 +3,39 @@
 """Core classes for concept map structure."""
 
 from zope.interface import implementer
-from scopes.interfaces import IConcept
 from scopes.storage.common import registerContainerClass, registry
 from scopes.storage.tracking import Container, Track
 
 
-@implementer(IConcept)
 class Concept(Track):
 
     headFields = ['name']
 
+    def parents(self, predicate=None):
+        return self.container.queryRels(second=self, predicate=predicate)
+
+    def children(self, predicate=None):
+        return self.container.queryRels(first=self, predicate=predicate)
+
 
 class Concepts(Container):
 
     insertOnChange = False
     indexes = None
+
+    def queryRels(self, **crit):
+        pred = crit.get(predicate)
+        if pred is not None and isinstance(pred, ('string', 'bytes')):
+            crit['predicate'] = self.storage.getContainer('pred').queryLast(name=pred)
+        for k, v in crit.items:
+            if isinstance(v, Track):
+                crit[k] = v.uid
+        rels = self.storage.getContainer('rel')
+        return rels.query(**crit)
  
 
+ # implementation of relationships between concepts using RDF-like triples
+
 class Predicate(Concept):
 
     prefix = 'pred'
@@ -37,6 +53,15 @@ class Triple(Track):
     headFields = ['first', 'second', 'predicate']
     prefix = 'rel'
 
+    def getFirst(self):
+        return self.container.storage.getItem(self.first)
+
+    def getSecond(self):
+        return self.container.storage.getItem(self.second)
+
+    def getPredicate(self):
+        return self.container.storage.getItem(self.second)
+
 
 @registerContainerClass
 class Rels(Container):
@@ -47,6 +72,8 @@ class Rels(Container):
     tableName = 'rels'
     insertOnChange = False
 
+    defaultPredicate = 'standard'
+
 
 # types stuff
 
@@ -75,7 +102,6 @@ class Types(Concepts):
 def storeType(storage, cls, name):
     types = storage.create(Types)
     types.save(Type(name, cls.prefix))
-    storage.commit()
 
 def setupCoreTypes(storage):
     for c in registry.values():

scopes/storage/tracking.py

@@ -169,7 +169,7 @@ class Container(object):
                 *r[1:-2], trackId=r[0],timeStamp=r[-2], data=r[-1], container=self)
 
     def setupWhere(self, crit):
-        return [self.table.c[k.lower()] == v for k, v in crit.items()]
+        return [self.table.c[k.lower()] == v for k, v in crit.items() if v is not None]
 
     def setupValues(self, track, withTrackId=False):
         values = {}