Synnefo

from django.core import exceptions

from django.db.models import DecimalField, SubfieldBase

from django.utils.translation import ugettext_lazy as _

import decimal

class IntDecimalField(DecimalField):

    __metaclass__ = SubfieldBase

    description = _("Integer number as decimal")

    def to_python(self, value):

        if value is None:

            return value

        try:

            return long(value)

        except (ValueError, TypeError):

            raise exceptions.ValidationError(self.error_messages['invalid'])

    def _to_decimal(self, value):

        if value is None:

            return value

        try:

            return decimal.Decimal(value)

        except decimal.InvalidOperation:

            raise exceptions.ValidationError(self.error_messages['invalid'])

    def get_db_prep_save(self, value, connection):

        return connection.ops.value_to_db_decimal(self._to_decimal(value),

                self.max_digits, self.decimal_places)

    def get_prep_value(self, value):

        return self._to_decimal(value)

    def formfield(self, **kwargs):

        defaults = {'form_class': forms.IntegerField}

        defaults.update(kwargs)

        return super(IntegerField, self).formfield(**defaults)

from south.modelsinspector import add_introspection_rules

add_introspection_rules([], ["^synnefo\.lib\.db\.intdecimalfield\.IntDecimalField"])

DECIMAL_DIGITS  =   38

def intDecimalField(verbose_name=None, name=None, **kwargs):

    # decimal_places is set here instead of the object constructor

    # in order to convince south

    return IntDecimalField(verbose_name, name, max_digits=DECIMAL_DIGITS, decimal_places=0, **kwargs)