Files
pretix_original/src/pretix/base/i18n.py
2016-09-20 16:13:13 +02:00

383 lines
13 KiB
Python

import copy
import json
from contextlib import contextmanager
from typing import Dict, List, Optional, Union
from django import forms
from django.conf import settings
from django.core.serializers.json import DjangoJSONEncoder
from django.db.models import Model, QuerySet, TextField
from django.utils import translation
from django.utils.formats import date_format, number_format
from django.utils.safestring import mark_safe
from django.utils.translation import ugettext
class LazyI18nString:
"""
This represents an internationalized string that is/was/will be stored in the database.
"""
def __init__(self, data: Optional[Union[str, Dict[str, str]]]):
"""
Creates a new i18n-aware string.
:param data: If this is a dictionary, it is expected to map language codes to translations.
If this is a string that can be parsed as JSON, it will be parsed and used as such a dictionary.
If this is anything else, it will be cast to a string and used for all languages.
"""
self.data = data
if isinstance(self.data, str) and self.data is not None:
try:
j = json.loads(self.data)
except ValueError:
pass
else:
self.data = j
def __str__(self) -> str:
"""
Evaluate the given string with respect to the currently active locale.
If no string is available in the currently active language, this will give you
the string in the system's default language. If this is unavailable as well, it
will give you the string in the first language available.
"""
return self.localize(translation.get_language() or settings.LANGUAGE_CODE)
def __bool__(self):
if not self.data:
return False
if isinstance(self.data, dict):
return any(self.data.values())
return True
def localize(self, lng: str) -> str:
"""
Evaluate the given string with respect to the locale defined by ``lng``.
If no string is available in the currently active language, this will give you
the string in the system's default language. If this is unavailable as well, it
will give you the string in the first language available.
:param lng: A locale code, e.g. ``de``. If you specify a code including a country
or region like ``de-AT``, exact matches will be used preferably, but if only
a ``de`` or ``de-AT`` translation exists, this might be returned as well.
"""
if self.data is None:
return ""
if isinstance(self.data, dict):
firstpart = lng.split('-')[0]
similar = [l for l in self.data.keys() if l.startswith(firstpart + "-") or firstpart == l]
if lng in self.data and self.data[lng]:
return self.data[lng]
elif firstpart in self.data:
return self.data[firstpart]
elif similar:
return self.data[similar[0]]
elif settings.LANGUAGE_CODE in self.data and self.data[settings.LANGUAGE_CODE]:
return self.data[settings.LANGUAGE_CODE]
elif len(self.data):
return list(self.data.items())[0][1]
else:
return ""
else:
return str(self.data)
def __repr__(self) -> str: # NOQA
return '<LazyI18nString: %s>' % repr(self.data)
def __lt__(self, other) -> bool: # NOQA
return str(self) < str(other)
def __format__(self, format_spec):
return self.__str__()
def __eq__(self, other):
if other is None:
return False
if hasattr(other, 'data'):
return self.data == other.data
return self.data == other
class LazyGettextProxy:
def __init__(self, lazygettext):
self.lazygettext = lazygettext
def __getitem__(self, item):
with language(item):
return str(ugettext(self.lazygettext))
def __contains__(self, item):
return True
def __str__(self):
return str(ugettext(self.lazygettext))
@classmethod
def from_gettext(cls, lazygettext):
l = LazyI18nString({})
l.data = cls.LazyGettextProxy(lazygettext)
return l
class I18nWidget(forms.MultiWidget):
"""
The default form widget for I18nCharField and I18nTextField. It makes
use of Django's MultiWidget mechanism and does some magic to save you
time.
"""
widget = forms.TextInput
def __init__(self, langcodes: List[str], field: forms.Field, attrs=None):
widgets = []
self.langcodes = langcodes
self.enabled_langcodes = langcodes
self.field = field
for lng in self.langcodes:
a = copy.copy(attrs) or {}
a['lang'] = lng
widgets.append(self.widget(attrs=a))
super().__init__(widgets, attrs)
def decompress(self, value):
data = []
first_enabled = None
any_filled = False
if not isinstance(value, LazyI18nString):
value = LazyI18nString(value)
for i, lng in enumerate(self.langcodes):
dataline = (
value.data[lng]
if value is not None and (
isinstance(value.data, dict) or isinstance(value.data, LazyI18nString.LazyGettextProxy)
) and lng in value.data
else None
)
any_filled = any_filled or (lng in self.enabled_langcodes and dataline)
if not first_enabled and lng in self.enabled_langcodes:
first_enabled = i
data.append(dataline)
if value and not isinstance(value.data, dict):
data[first_enabled] = value.data
return data
def render(self, name, value, attrs=None):
if self.is_localized:
for widget in self.widgets:
widget.is_localized = self.is_localized
# value is a list of values, each corresponding to a widget
# in self.widgets.
if not isinstance(value, list):
value = self.decompress(value)
output = []
final_attrs = self.build_attrs(attrs)
id_ = final_attrs.get('id', None)
for i, widget in enumerate(self.widgets):
if self.langcodes[i] not in self.enabled_langcodes:
continue
try:
widget_value = value[i]
except IndexError:
widget_value = None
if id_:
final_attrs = dict(
final_attrs,
id='%s_%s' % (id_, i),
title=self.langcodes[i]
)
output.append(widget.render(name + '_%s' % i, widget_value, final_attrs))
return mark_safe(self.format_output(output))
def format_output(self, rendered_widgets):
return '<div class="i18n-form-group">%s</div>' % super().format_output(rendered_widgets)
class I18nTextInput(I18nWidget):
widget = forms.TextInput
class I18nTextarea(I18nWidget):
widget = forms.Textarea
class I18nFormField(forms.MultiValueField):
"""
The form field that is used by I18nCharField and I18nTextField. It makes use
of Django's MultiValueField mechanism to create one sub-field per available
language.
It contains special treatment to make sure that a field marked as "required" is validated
as "filled out correctly" if *at least one* translation is filled it. It is never required
to fill in all of them. This has the drawback that the HTML property ``required`` is set on
none of the fields as this would lead to irritating behaviour.
:param langcodes: An iterable of locale codes that the widget should render a field for. If
omitted, fields will be rendered for all languages supported by pretix.
"""
def compress(self, data_list):
langcodes = self.langcodes
data = {}
for i, value in enumerate(data_list):
data[langcodes[i]] = value
return LazyI18nString(data)
def clean(self, value):
if isinstance(value, LazyI18nString):
# This happens e.g. if the field is disabled
return value
found = False
clean_data = []
errors = []
for i, field in enumerate(self.fields):
try:
field_value = value[i]
except IndexError:
field_value = None
if field_value not in self.empty_values:
found = True
try:
clean_data.append(field.clean(field_value))
except forms.ValidationError as e:
# Collect all validation errors in a single list, which we'll
# raise at the end of clean(), rather than raising a single
# exception for the first error we encounter. Skip duplicates.
errors.extend(m for m in e.error_list if m not in errors)
if errors:
raise forms.ValidationError(errors)
if self.one_required and not found:
raise forms.ValidationError(self.error_messages['required'], code='required')
out = self.compress(clean_data)
self.validate(out)
self.run_validators(out)
return out
def __init__(self, *args, **kwargs):
fields = []
defaults = {
'widget': self.widget,
'max_length': kwargs.pop('max_length', None),
}
self.langcodes = kwargs.pop('langcodes', [l[0] for l in settings.LANGUAGES])
self.one_required = kwargs.get('required', True)
kwargs['required'] = False
kwargs['widget'] = kwargs['widget'](
langcodes=self.langcodes, field=self, **kwargs.pop('widget_kwargs', {})
)
defaults.update(**kwargs)
for lngcode in self.langcodes:
defaults['label'] = '%s (%s)' % (defaults.get('label'), lngcode)
fields.append(forms.CharField(**defaults))
super().__init__(
fields=fields, require_all_fields=False, *args, **kwargs
)
class I18nFieldMixin:
form_class = I18nFormField
widget = I18nTextInput
def __init__(self, *args, **kwargs):
self.event = kwargs.pop('event', None)
super().__init__(*args, **kwargs)
def to_python(self, value):
if isinstance(value, LazyI18nString):
return value
return LazyI18nString(value)
def get_prep_value(self, value):
if isinstance(value, LazyI18nString):
value = value.data
if isinstance(value, dict):
return json.dumps({k: v for k, v in value.items() if v}, sort_keys=True)
return value
def get_prep_lookup(self, lookup_type, value): # NOQA
raise TypeError('Lookups on i18n string currently not supported.')
def from_db_value(self, value, expression, connection, context):
return LazyI18nString(value)
def formfield(self, **kwargs):
defaults = {'form_class': self.form_class, 'widget': self.widget}
defaults.update(kwargs)
return super().formfield(**defaults)
class I18nCharField(I18nFieldMixin, TextField):
"""
A CharField which takes internationalized data. Internally, a TextField dabase
field is used to store JSON. If you interact with this field, you will work
with LazyI18nString instances.
"""
widget = I18nTextInput
class I18nTextField(I18nFieldMixin, TextField):
"""
Like I18nCharField, but for TextFields.
"""
widget = I18nTextarea
class I18nJSONEncoder(DjangoJSONEncoder):
def default(self, obj):
if isinstance(obj, LazyI18nString):
return obj.data
elif isinstance(obj, QuerySet):
return list(obj)
elif isinstance(obj, Model):
return {'type': obj.__class__.__name__, 'id': obj.id}
else:
return super().default(obj)
class LazyDate:
def __init__(self, value):
self.value = value
def __format__(self, format_spec):
return self.__str__()
def __str__(self):
return date_format(self.value, "SHORT_DATE_FORMAT")
class LazyNumber:
def __init__(self, value, decimal_pos=2):
self.value = value
self.decimal_pos = decimal_pos
def __format__(self, format_spec):
return self.__str__()
def __str__(self):
return number_format(self.value, decimal_pos=self.decimal_pos)
@contextmanager
def language(lng):
_lng = translation.get_language()
translation.activate(lng or settings.LANGUAGE_CODE)
try:
yield
finally:
translation.activate(_lng)
class LazyLocaleException(Exception):
def __init__(self, msg, msgargs=None):
self.msg = msg
self.msgargs = msgargs
super().__init__(msg, msgargs)
def __str__(self):
if self.msgargs:
return ugettext(self.msg) % self.msgargs
else:
return ugettext(self.msg)