Changeset 138

Timestamp:

01/07/06 22:38:54

Author:

fumanchu

Message:

New TriggerProperty? class, a subclass of UnitProperty? to help write triggers which should fire immediately on __set__.

Files:

• trunk/units.py (modified) (2 diffs)

trunk/units.py

@@ -13 +13 @@
-
-__all__ = ['UnitAssociation', 'ToMany', 'ToOne', 'UnitJoin',
-
+TriggerProperty', '
-           'UnitSequencerInteger', 'UnitSequencerNull',
-           'UnitSequencerUnicode',
@@ -349 +349 @@
-
-
+class TriggerProperty(UnitProperty):
+    """UnitProperty subclass for managing immediate triggers on set.
+    
+    The __set__ method will call the on_set method, which should then
+    deal with the new value.
+    """
+    
+    def __set__(self, unit, value):
+        if self.coerce:
+            value = self.coerce(unit, value)
+        oldvalue = unit._properties[self.key]
+        if oldvalue != value:
+            unit._properties[self.key] = value
+            if unit.sandbox:
+                self.on_set(unit, oldvalue)
+    
+    def on_set(self, unit, oldvalue):
+        pass
+
+
-class MetaUnit(type):
-