Execute the following steps to define the multilingual character field and multilingual text field:

1. Open the fields.py file and create the base multilingual field, as follows:

# utils/fields.py
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,
                            virtual_only=False):
        def translated_value():
            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, virtual_only)

2. In the same file, subclass the base field for character and text field forms, as follows:

class MultilingualCharField(models.CharField, MultilingualField):
    pass


class MultilingualTextField(models.TextField, MultilingualField):
    pass

Now, we'll consider an example of how to use the multilingual fields in your app, as follows:

1. First, set multiple languages in the settings for your project:

# settings.py or config/base.py
LANGUAGE_CODE = "en-us"

LANGUAGES = (
    ("en-us", "US English"),
    ("en-gb", "British English"),
    ("de", "Deutsch"),
    ("fr", "Français"),
    ("lt", "Lietuvių kalba"),
)

2. Then, open the models.py file from the demo_app and create the multilingual fields for the Idea model, as follows:

# demo_app/models.py
from django.db import models 
from django.utils.translation import ugettext_lazy as _ 
 
from utils.fields import (
    MultilingualCharField,
    MultilingualTextField)

class Idea(models.Model):
    class Meta:
        verbose_name = _("Idea")
        verbose_name_plural = _("Ideas")

    title = MultilingualCharField(_("Title"),
                                  max_length=200)
    description = MultilingualTextField(_("Description"),
                                        blank=True)
    content = models.MultilingualTextField(_("Content"))

    def __str__(self):
        return self.title