Alexandru Arnăutu e4bd26ece2
Add support for storing Float values (#80)
* Add LocalizedFloatValue

* Add LocalizedFloatField

* Add tests for float field

* Create LocalizedNumericValue with __int__ and __float__ methods
2020-03-10 09:21:11 +02:00

92 lines
3.3 KiB
Python

from typing import Optional, Union, Dict
from django.conf import settings
from django.db.utils import IntegrityError
from .field import LocalizedField
from ..value import LocalizedValue, LocalizedFloatValue
from ..forms import LocalizedIntegerFieldForm
class LocalizedFloatField(LocalizedField):
"""Stores float as a localized value."""
attr_class = LocalizedFloatValue
@classmethod
def from_db_value(cls, value, *_) -> Optional[LocalizedFloatValue]:
db_value = super().from_db_value(value)
if db_value is None:
return db_value
# if we were used in an expression somehow then it might be
# that we're returning an individual value or an array, so
# we should not convert that into an :see:LocalizedFloatValue
if not isinstance(db_value, LocalizedValue):
return db_value
return cls._convert_localized_value(db_value)
def to_python(self, value: Union[Dict[str, int], int, None]) -> LocalizedFloatValue:
"""Converts the value from a database value into a Python value."""
db_value = super().to_python(value)
return self._convert_localized_value(db_value)
def get_prep_value(self, value: LocalizedFloatValue) -> dict:
"""Gets the value in a format to store into the database."""
# apply default values
default_values = LocalizedFloatValue(self.default)
if isinstance(value, LocalizedFloatValue):
for lang_code, _ in settings.LANGUAGES:
local_value = value.get(lang_code)
if local_value is None:
value.set(lang_code, default_values.get(lang_code, None))
prepped_value = super().get_prep_value(value)
if prepped_value is None:
return None
# make sure all values are proper floats
for lang_code, _ in settings.LANGUAGES:
local_value = prepped_value[lang_code]
try:
if local_value is not None:
float(local_value)
except (TypeError, ValueError):
raise IntegrityError('non-float value in column "%s.%s" violates '
'float constraint' % (self.name, lang_code))
# convert to a string before saving because the underlying
# type is hstore, which only accept strings
prepped_value[lang_code] = str(local_value) if local_value is not None else None
return prepped_value
def formfield(self, **kwargs):
"""Gets the form field associated with this field."""
defaults = {
'form_class': LocalizedIntegerFieldForm
}
defaults.update(kwargs)
return super().formfield(**defaults)
@staticmethod
def _convert_localized_value(value: LocalizedValue) -> LocalizedFloatValue:
"""Converts from :see:LocalizedValue to :see:LocalizedFloatValue."""
float_values = {}
for lang_code, _ in settings.LANGUAGES:
local_value = value.get(lang_code, None)
if local_value is None or local_value.strip() == '':
local_value = None
try:
float_values[lang_code] = float(local_value)
except (ValueError, TypeError):
float_values[lang_code] = None
return LocalizedFloatValue(float_values)