initial checkin

fields.py

@@ -0,0 +1,57 @@
+
+class ValidationError(Exception):
+    pass
+
+class Field(object):
+    creation_counter = 0
+
+    def __init__(self, name=None, max_length=0, required=True):
+        self.name = name
+        self._value = None
+        self.max_length = max_length
+        self.required = required
+        self.creation_counter = Field.creation_counter
+        Field.creation_counter += 1
+
+    def validate(self):
+        raise NotImplemented()
+
+    def get_data(self):
+        raise NotImplemented()
+    
+    def __setvalue(self, value):
+        self._value = value
+
+    def __getvalue(self):   
+        return self._value
+    
+    value = property(__getvalue, __setvalue)
+
+    def __repr__(self):
+        return self.name
+
+
+class TextField(Field):    
+    def validate(self):
+        if self.value == None and self.required:
+            raise ValidationError("value required")
+        if len(self.value) > self.max_length:
+            raise ValidationError("value is too long")
+
+    def get_data(self):
+        return (self.value or "").encode('ascii').ljust(self.max_length)
+
+class StateField(TextField):
+    def __init__(self, name=None, required=True):
+        return super(StateField, self).__init__(name=name, max_length=2, required=required)
+
+class MoneyField(Field):
+    def validate(self):
+        if self.value == None and self.required:
+            raise ValidationError("value required")
+        if len(str(int((self.value or 0)*100))) > self.max_length:
+            raise ValidationError("value is too long")
+
+    def get_data(self):
+        return str(int((self.value or 0)*100)).encode('ascii').zfill(self.max_length)
+