fixed some issues resulting from upgrading sqlalchemy, made more ORM-y

[bluechips.git] / bluechips / model / types.py

diff --git a/bluechips/model/types.py b/bluechips/model/types.py
index 1c54e764fb91e4d6907f68575cab22ffb6f59b17..d4454813bd7e5463fc513518359b755b53abd25f 100644 (file)
--- a/bluechips/model/types.py
+++ b/bluechips/model/types.py
@@ -5,34 +5,77 @@ Define special types used in BlueChips
 import sqlalchemy as sa
 from bluechips.lib.subclass import SmartSubclass
 
+from weakref import WeakValueDictionary
+
 class Currency(object):
+    """
+    Store currency values as an integral number of cents
+    """
     __metaclass__ = SmartSubclass(int)
-    def __init__(self, value):
-        if isinstance(value, str):
-            self.value = int(float(value) * 100)
+    __old_values__ = WeakValueDictionary()
+    def __new__(cls, value):
+        if value is None:
+            value = 0
+        elif isinstance(value, str):
+            value = int(float(value) * 100)
         else:
-            self.value = int(value)
+            value = int(value)
+        
+        if value not in cls.__old_values__:
+            new_object = super(cls, cls).__new__(cls)
+            new_object.value = value
+            cls.__old_values__[value] = new_object
+            return new_object
+        else:
+            return cls.__old_values__[value]
     
     def __int__(self):
+        """
+        If I don't define this, SmartSubclass will return
+        Currency(int(self.value))
+        """
         return self.value
     def __float__(self):
+        """
+        If I don't define this, SmartSubclass will return
+        Currency(float(self.value))
+        """
         return float(self.value)
     def __long__(self):
+        """
+        If I don't define this, SmartSubclass will return
+        Currency(long(self.value))
+        """
         return long(self.value)
     
     def __cmp__(self, other):
-        try:
+        """
+        This is overridden for when validators compare a Currency to
+        ''
+        """
+        if other == '':
+            return 1
+        else:
             return self.value.__cmp__(int(other))
-        except:
-            return self.value.__cmp__(0)
     
     def __mul__(self, other):
+        """
+        If I don't define this, SmartSubclass will convert the other
+        argument to an int
+        """
         return Currency(self.value * other)
     def __rmul__(self, other):
+        """
+        If I don't define this, SmartSubclass will convert the other
+        argument to an int
+        """
         return self.__mul__(other)
     
     def __str_no_dollar__(self):
-        return str(self)[1:]
+        """
+        Get to the formatted string without the dollar sign
+        """
+        return str(self).replace('$', '')
     
     def __repr__(self):
         return '%s("%s")' % (self.__class__.__name__, str(self))
@@ -40,7 +83,7 @@ class Currency(object):
         sign = '-' if self.value < 0 else ''
         cents = abs(self.value) % 100
         dollars = (abs(self.value) - cents) / 100
-        return '$%s%s.%.02d' % (sign, dollars, cents)
+        return '%s$%s.%.02d' % (sign, dollars, cents)
 
 class DBCurrency(sa.types.TypeDecorator):
     """
@@ -56,3 +99,4 @@ class DBCurrency(sa.types.TypeDecorator):
     
     def convert_result_value(self, value, engine):
         return Currency(value)
+    process_result_value = convert_result_value