Source code for quantityfield.widgets

from django.forms.widgets import MultiWidget, NumberInput, Select

import re

from .units import ureg


class QuantityWidget(MultiWidget):
    def __init__(self, *, attrs=None, base_units=None, allowed_types=None):
        self.ureg = ureg
        choices = self.get_choices(allowed_types)
        self.base_units = base_units
        attrs = attrs or {}
        attrs.setdefault("step", "any")
        widgets = (NumberInput(attrs=attrs), Select(attrs=attrs, choices=choices))
        super(QuantityWidget, self).__init__(widgets, attrs)

    def get_choices(self, allowed_types=None):
        allowed_types = allowed_types or dir(self.ureg)
        return [(x, x) for x in allowed_types]

    def decompress(self, value):
        non_decimal = re.compile(r"[^\d.]+")
        if value:
            number_value = non_decimal.sub("", str(value))
            return [number_value, self.base_units]
        return [None, self.base_units]