[Checkins] SVN: z3c.relationfield/trunk/ Fix a comparison bug.

[Martijn Faassen]

Log message for revision 94883:
  Fix a comparison bug.
  

Changed:
  U   z3c.relationfield/trunk/CHANGES.txt
  U   z3c.relationfield/trunk/src/z3c/relationfield/README.txt
  U   z3c.relationfield/trunk/src/z3c/relationfield/relation.py

-=-
Modified: z3c.relationfield/trunk/CHANGES.txt
===================================================================
--- z3c.relationfield/trunk/CHANGES.txt	2009-01-20 21:09:53 UTC (rev 94882)
+++ z3c.relationfield/trunk/CHANGES.txt	2009-01-20 21:12:04 UTC (rev 94883)
@@ -1,11 +1,14 @@
 CHANGES
 *******
 
-0.4 (unreleased)
-================
+0.3.1 (unreleased)
+==================
 
-* ...
+* Introduce sensible sort order for relations, based on a
+  ``(from_attribute, from_path, to_path)`` tuple.
 
+* Relations will now never compare to ``None``. 
+
 0.3 (2009-01-19)
 ================
 

Modified: z3c.relationfield/trunk/src/z3c/relationfield/README.txt
===================================================================
--- z3c.relationfield/trunk/src/z3c/relationfield/README.txt	2009-01-20 21:09:53 UTC (rev 94882)
+++ z3c.relationfield/trunk/src/z3c/relationfield/README.txt	2009-01-20 21:12:04 UTC (rev 94883)
@@ -378,6 +378,27 @@
   >>> l[1].from_path
   u'b-2'
 
+Relations are sortable
+======================
+
+Relations are sorted by default on a combination of the relation name,
+the path of the object the relation is one and the path of the object
+the relation is pointing to.
+
+Let's query all relations availble right now and sort them::
+
+  >>> l = sorted(catalog.findRelations())
+  >>> len(l)
+  2
+  >>> l[0].from_attribute
+  'rel'
+  >>> l[1].from_attribute
+  'rel'
+  >>> l[0].from_path
+  u'b'
+  >>> l[1].from_path
+  u'b-2'
+
 Removing an object with relations
 =================================
 
@@ -428,6 +449,11 @@
   >>> b.rel.to_id is None
   True
 
+A broken relation isn't equal to ``None`` (this was a bug)::
+
+  >>> b.rel == None
+  False
+
 RelationList
 ============
 

Modified: z3c.relationfield/trunk/src/z3c/relationfield/relation.py
===================================================================
--- z3c.relationfield/trunk/src/z3c/relationfield/relation.py	2009-01-20 21:09:53 UTC (rev 94882)
+++ z3c.relationfield/trunk/src/z3c/relationfield/relation.py	2009-01-20 21:12:04 UTC (rev 94883)
@@ -59,9 +59,12 @@
 
     def __cmp__(self, other):
         if other is None:
-            return cmp(self.to_id, None)
-        return cmp(self.to_id, other.to_id)
+            return cmp(self._sort_key(), None)
+        return cmp(self._sort_key(), other._sort_key())
 
+    def _sort_key(self):
+        return (self.from_attribute, self.from_path, self.to_path)
+    
     def broken(self, to_path):
         self._broken_to_path = to_path
         self.to_id = None