betterdecimalfield.py

"""
Sample DecimalField.
"""

from wtforms import DecimalField


class BetterDecimalField(DecimalField):
    """
    Very similar to WTForms DecimalField, except with the option of rounding
    the data always.
    """
    def __init__(self, label=None, validators=None, places=2, rounding=None,
                 round_always=False, **kwargs):
        super(BetterDecimalField, self).__init__(
            label=label, validators=validators, places=places, rounding=
            rounding, **kwargs)
        self.round_always = round_always

    def process_formdata(self, valuelist):
        if valuelist:
            try:
                self.data = decimal.Decimal(valuelist[0])
                if self.round_always and hasattr(self.data, 'quantize'):
                    exp = decimal.Decimal('.1') ** self.places
                    if self.rounding is None:
                        quantized = self.data.quantize(exp)
                    else:
                        quantized = self.data.quantize(exp, rounding=
                                                       self.rounding)
                    self.data = quantized
            except (decimal.InvalidOperation, ValueError):
                self.data = None
                raise ValueError(self.gettext('Not a valid decimal value'))