Fixed #2365, #3324 -- Renamed FloatField to DecimalField and changed the code

to return Decimal instances in Python for this field. Backwards incompatible
change.

Added a real FloatField (stores floats in the database) and support for
FloatField and DecimalField in newforms (analogous to IntegerField).

Included decimal.py module (as django.utils._decimal) from Python 2.4. This is
license compatible with Django and included for Python 2.3 compatibility only.

Large portions of this work are based on patches from Andy Durdin and Jorge
Gajon.



git-svn-id: http://code.djangoproject.com/svn/django/trunk@5302 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/newforms/fields.py

@@ -19,7 +19,7 @@ __all__ = (
     'DEFAULT_DATETIME_INPUT_FORMATS', 'DateTimeField',
     'RegexField', 'EmailField', 'URLField', 'BooleanField',
     'ChoiceField', 'NullBooleanField', 'MultipleChoiceField',
-    'ComboField', 'MultiValueField',
+    'ComboField', 'MultiValueField', 'FloatField', 'DecimalField',
     'SplitDateTimeField',
 )
 
@@ -31,6 +31,11 @@ try:
 except NameError:
     from sets import Set as set # Python 2.3 fallback
 
+try:
+    from decimal import Decimal
+except ImportError:
+    from django.utils._decimal import Decimal   # Python 2.3 fallback
+
 class Field(object):
     widget = TextInput # Default widget to use when rendering this type of Field.
     hidden_widget = HiddenInput # Default widget to use when rendering this as "hidden".
@@ -134,6 +139,67 @@ class IntegerField(Field):
             raise ValidationError(gettext(u'Ensure this value is greater than or equal to %s.') % self.min_value)
         return value
 
+class FloatField(Field):
+    def __init__(self, max_value=None, min_value=None, *args, **kwargs):
+        self.max_value, self.min_value = max_value, min_value
+        Field.__init__(self, *args, **kwargs)
+
+    def clean(self, value):
+        """
+        Validates that float() can be called on the input. Returns a float.
+        Returns None for empty values.
+        """
+        super(FloatField, self).clean(value)
+        if not self.required and value in EMPTY_VALUES:
+            return None
+        try:
+            value = float(value)
+        except (ValueError, TypeError):
+            raise ValidationError(gettext('Enter a number.'))
+        if self.max_value is not None and value > self.max_value:
+            raise ValidationError(gettext('Ensure this value is less than or equal to %s.') % self.max_value)
+        if self.min_value is not None and value < self.min_value:
+            raise ValidationError(gettext('Ensure this value is greater than or equal to %s.') % self.min_value)
+        return value
+
+decimal_re = re.compile(r'^-?(?P<digits>\d+)(\.(?P<decimals>\d+))?$')
+
+class DecimalField(Field):
+    def __init__(self, max_value=None, min_value=None, max_digits=None, decimal_places=None, *args, **kwargs):
+        self.max_value, self.min_value = max_value, min_value
+        self.max_digits, self.decimal_places = max_digits, decimal_places
+        Field.__init__(self, *args, **kwargs)
+
+    def clean(self, value):
+        """
+        Validates that the input is a decimal number. Returns a Decimal
+        instance. Returns None for empty values. Ensures that there are no more
+        than max_digits in the number, and no more than decimal_places digits
+        after the decimal point.
+        """
+        super(DecimalField, self).clean(value)
+        if not self.required and value in EMPTY_VALUES:
+            return None
+        value = value.strip()
+        match = decimal_re.search(value)
+        if not match:
+            raise ValidationError(gettext('Enter a number.'))
+        else:
+            value = Decimal(value)
+        digits = len(match.group('digits') or '')
+        decimals = len(match.group('decimals') or '')
+        if self.max_value is not None and value > self.max_value:
+            raise ValidationError(gettext('Ensure this value is less than or equal to %s.') % self.max_value)
+        if self.min_value is not None and value < self.min_value:
+            raise ValidationError(gettext('Ensure this value is greater than or equal to %s.') % self.min_value)
+        if self.max_digits is not None and (digits + decimals) > self.max_digits:
+            raise ValidationError(gettext('Ensure that there are no more than %s digits in total.') % self.max_digits)
+        if self.decimal_places is not None and decimals > self.decimal_places:
+            raise ValidationError(gettext('Ensure that there are no more than %s decimal places.') % self.decimal_places)
+        if self.max_digits is not None and self.decimal_places is not None and digits > (self.max_digits - self.decimal_places):
+            raise ValidationError(gettext('Ensure that there are no more than %s digits before the decimal point.') % (self.max_digits - self.decimal_places))
+        return value
+
 DEFAULT_DATE_INPUT_FORMATS = (
     '%Y-%m-%d', '%m/%d/%Y', '%m/%d/%y', # '2006-10-25', '10/25/2006', '10/25/06'
     '%b %d %Y', '%b %d, %Y',            # 'Oct 25 2006', 'Oct 25, 2006'