Django高级编程之自定义Field实现多语言

自定义数据库字段

扩展默认的models.CharField和models.TextField使之成为支持多语言的字段。
可以轻松实现复用，无需配置多余选项

from django.conf import settings
from django.db import models
from django.utils.translation import get_language

class MultilingualField(models.Field):
SUPPORTED_FIELD_TYPES = [models.CharField, models.TextField]

def __init__(self, verbose_name=None, **kwargs):
 self.localized_field_model = None
 for model in MultilingualField.SUPPORTED_FIELD_TYPES:
  if issubclass(self.__class__, model):
   self.localized_field_model = model
 self._blank = kwargs.get("blank", False)
 self._editable = kwargs.get("editable", True)
 super().__init__(verbose_name, **kwargs)

@staticmethod
def localized_field_name(name, lang_code):
 lang_code_safe = lang_code.replace("-", "_")
 return f"{name}_{lang_code_safe}"

def get_localized_field(self, lang_code, lang_name):
 _blank = (self._blank
    if lang_code == settings.LANGUAGE_CODE
    else True)
 localized_field = self.localized_field_model(
  f"{self.verbose_name} ({lang_name})",
  name=self.name,
  primary_key=self.primary_key,
  max_length=self.max_length,
  unique=self.unique,
  blank=_blank,
  null=False, # we ignore the null argument!
  db_index=self.db_index,
  default=self.default or "",
  editable=self._editable,
  serialize=self.serialize,
  choices=self.choices,
  help_text=self.help_text,
  db_column=None,
  db_tablespace=self.db_tablespace)
 return localized_field

def contribute_to_class(self, cls, name,
      private_only=False):
 def translated_value(self):
  language = get_language()
  val = self.__dict__.get(
   MultilingualField.localized_field_name(
     name, language))
  if not val:
   val = self.__dict__.get(
    MultilingualField.localized_field_name(
      name, settings.LANGUAGE_CODE))
  return val

# generate language-specific fields dynamically
 if not cls._meta.abstract:
  if self.localized_field_model:
   for lang_code, lang_name in settings.LANGUAGES:
    localized_field = self.get_localized_field(
     lang_code, lang_name)
    localized_field.contribute_to_class(
      cls,
      MultilingualField.localized_field_name(
        name, lang_code))

setattr(cls, name, property(translated_value))
  else:
   super().contribute_to_class(
    cls, name, private_only)

class MultilingualCharField(models.CharField, MultilingualField):
pass

class MultilingualTextField(models.TextField, MultilingualField):
pass

这里定义了 MultilingualCharField 和 MultilingualTextField字段

使用方法

settings.py中配置多语言

LANGUAGE_CODE = 'zh-hans'
TIME_ZONE = 'Asia/Shanghai'

LANGUAGES = (
('en-us', 'US English'),
('zh-hans', 'Asia/Shanghai')
)

默认语言设置为中文，多语言为英语

models.py中使用字段

from django.db import models
from django.utils.translation import ugettext_lazy as _

from utils.fields import (
MultilingualCharField,
MultilingualTextField
)

class Item(models.Model):
title = MultilingualCharField(_('Title'), max_length=200)
description = MultilingualTextField(_('Description'), blank=True)
content = MultilingualTextField(_('Content'))

def __str__(self):
 return self.title

效果图

可以看到，数据库字段自动生成了相应语言的字段

当用户语言切换到其他，可以自动适配实现多语言

来源：https://www.cnblogs.com/PyKK2019/p/11117488.html