Code source de django.contrib.postgres.forms.ranges

import warnings

from psycopg2.extras import DateRange, DateTimeTZRange, NumericRange

from django import forms
from django.core import exceptions
from django.forms.widgets import MultiWidget
from django.utils.deprecation import RemovedInDjango31Warning
from django.utils.translation import gettext_lazy as _

__all__ = [
    'BaseRangeField', 'IntegerRangeField', 'DecimalRangeField',
    'DateTimeRangeField', 'DateRangeField', 'FloatRangeField', 'RangeWidget',
]


class BaseRangeField(forms.MultiValueField):
    default_error_messages = {
        'invalid': _('Enter two valid values.'),
        'bound_ordering': _('The start of the range must not exceed the end of the range.'),
    }

    def __init__(self, **kwargs):
        if 'widget' not in kwargs:
            kwargs['widget'] = RangeWidget(self.base_field.widget)
        if 'fields' not in kwargs:
            kwargs['fields'] = [self.base_field(required=False), self.base_field(required=False)]
        kwargs.setdefault('required', False)
        kwargs.setdefault('require_all_fields', False)
        super().__init__(**kwargs)

    def prepare_value(self, value):
        lower_base, upper_base = self.fields
        if isinstance(value, self.range_type):
            return [
                lower_base.prepare_value(value.lower),
                upper_base.prepare_value(value.upper),
            ]
        if value is None:
            return [
                lower_base.prepare_value(None),
                upper_base.prepare_value(None),
            ]
        return value

    def compress(self, values):
        if not values:
            return None
        lower, upper = values
        if lower is not None and upper is not None and lower > upper:
            raise exceptions.ValidationError(
                self.error_messages['bound_ordering'],
                code='bound_ordering',
            )
        try:
            range_value = self.range_type(lower, upper)
        except TypeError:
            raise exceptions.ValidationError(
                self.error_messages['invalid'],
                code='invalid',
            )
        else:
            return range_value


[docs]class IntegerRangeField(BaseRangeField):
    default_error_messages = {'invalid': _('Enter two whole numbers.')}
    base_field = forms.IntegerField
    range_type = NumericRange


[docs]class DecimalRangeField(BaseRangeField):
    default_error_messages = {'invalid': _('Enter two numbers.')}
    base_field = forms.DecimalField
    range_type = NumericRange


[docs]class FloatRangeField(DecimalRangeField):
    base_field = forms.FloatField

    def __init__(self, **kwargs):
        warnings.warn(
            'FloatRangeField is deprecated in favor of DecimalRangeField.',
            RemovedInDjango31Warning, stacklevel=2,
        )
        super().__init__(**kwargs)


[docs]class DateTimeRangeField(BaseRangeField):
    default_error_messages = {'invalid': _('Enter two valid date/times.')}
    base_field = forms.DateTimeField
    range_type = DateTimeTZRange


[docs]class DateRangeField(BaseRangeField):
    default_error_messages = {'invalid': _('Enter two valid dates.')}
    base_field = forms.DateField
    range_type = DateRange


[docs]class RangeWidget(MultiWidget):
    def __init__(self, base_widget, attrs=None):
        widgets = (base_widget, base_widget)
        super().__init__(widgets, attrs)

[docs]    def decompress(self, value):
        if value:
            return (value.lower, value.upper)
        return (None, None)