How it works...

We keep the language-specific fields of the default language in the Idea model itself. The translations for each language are in the IdeaTranslations model, which will be listed in the administration as an inline translation. IdeaTranslations don't have the language choices at the model for a reason – we don't want to create migrations every time a new language is added or some language is removed. Instead, the language choices are set in the administration form, also making sure that the default language is skipped or not available for selection in the list. The language choices are restricted using the LanguageChoicesForm class.

To get a specific field in the current language, you would use the fields defined as TranslatedField. In the template, that would look like the following:

<h1>{{ idea.translated_title }}</h1>
<div>{{ idea.translated_content|urlize|linebreaks }}</div>

To order items by a translated title in a specific language, you would use the annotate() method as follows:

>>> from django.conf import settings
>>> from django.db import models
>>> lang_code = input("Enter language code: ")

>>> if lang_code == settings.LANGUAGE_CODE:
...     qs = Idea.objects.annotate(
...         title_translation=models.F("title"),
...         content_translation=models.F("content"),
...     )
... else:
...     qs = Idea.objects.filter(
...         translations__language=lang_code,
...     ).annotate(
...         title_translation=models.F("translations__title"),
...         content_translation=models.F("translations__content"),
...     )

>>> qs = qs.order_by("title_translation")

>>> for idea in qs:
...     print(idea.title_translation)

In this example, we prompt for a language code in the Django shell. If the language is the default one, we store the title and content as the title_translation and the content_translation from the Idea model. If there is another language chosen, we read the title and content as title_translation and content_translation from the IdeaTranslations model  with the chosen language.

Afterward, we can filter or order QuerySet by title_translation or content_translation.