wagtail_translated_model.py

class TranslatedField(object):
    def __init__(self, fieldname):
        self.fieldname = fieldname

    def get_translated_field(self, instance, language):
        return getattr(instance, "_".join([self.fieldname, language]))

    def __get__(self, instance, owner):
        language = get_language()
        translation = self.get_translated_field(instance, language)
        return translation or language != 'en' and self.get_translated_field(instance, 'en') or translation


class TranslatedTitleMixin(models.Model):
    title_fr = models.CharField(max_length=255, blank=True)
    title_es = models.CharField(max_length=255, blank=True)

    def get_title(self):
        language = get_language()

        fr = self.title_fr
        es = self.title_es
        en = self.title

        if language == 'fr' and fr:
            return fr
        elif language == 'es' and es:
            return es
        else:
            return en

    class Meta:
        abstract = True


class TranslatedPageMeta(PageBase):
    """ Metaclass for `TranslatedPage` abstract base class, ensuring subclasses
    have the correct `.edit_handler` attribute. This can't be directly declared
    on the base class itself, because it refers to the foreign-language content
    panels, which are only declared on the child classes. We don't bother about
    declaring the `.edit_handler` attribute on the (abstract) base class, hence
    the try/except clause.
    """
    def __init__(classobject, classname, baseclasses, attrs):
        try:
            classobject.edit_handler = TabbedInterface([
                ObjectList(classobject.english_content_panels, heading='En'),
                ObjectList(classobject.french_content_panels + [classobject.french_extra_panels], heading='Fr'),
                ObjectList(classobject.spanish_content_panels + [classobject.spanish_extra_panels], heading='Es'),
                ObjectList(classobject.content_panels, heading='Common'),
                ObjectList(classobject.promote_panels, heading='Promote'),
                ObjectList(Page.settings_panels, heading='Settings', classname="settings"),
            ])
        except AttributeError:
            # Presumably one of the .english .french or .spanish_content_panels
            # attributes is missing. Aborting is quite safe: we just default to
            # the return value of wagtailadmin.views.page.get_page_edit_handler
            pass
        super().__init__(classname, baseclasses, attrs)


class TranslatedPage(Page, TranslatedTitleMixin, metaclass=TranslatedPageMeta):
    is_abstract = True
    feed_title_en = models.CharField(max_length=30, blank=True, help_text="The title when this page is displayed as a link elsewhere on the site.")
    feed_title_fr = models.CharField(max_length=30, blank=True, help_text="The title when this page is displayed as a link elsewhere on the site.")
    feed_title_es = models.CharField(max_length=30, blank=True, help_text="The title when this page is displayed as a link elsewhere on the site.")
    feed_summary_en = models.TextField(blank=True, help_text="A description for when this page is displayed as a link elsewhere on the site.")
    feed_summary_fr = models.TextField(blank=True, help_text="A description for when this page is displayed as a link elsewhere on the site.")
    feed_summary_es = models.TextField(blank=True, help_text="A description for when this page is displayed as a link elsewhere on the site.")

    _feed_title = TranslatedField('listings_title')
    _feed_summary = TranslatedField('listings_summary')

    class Meta:
        abstract = True

    def feed_title(self):
        return self._feed_title or self.get_title()

    def feed_summary(self):
        try:
            summary_text = self.summary_text
        except AttributeError:
            summary_text = ""
        return self._feed_summary or summary_text

    search_fields = Page.search_fields + (
        index.SearchField('title_fr'),
        index.SearchField('title_es'),
    )

    french_extra_panels = MultiFieldPanel(
        (
            FieldPanel('feed_title_fr'),
            FieldPanel('feed_summary_fr'),
        ),
        "Feeds"
    )

    spanish_extra_panels = MultiFieldPanel(
        (
            FieldPanel('feed_title_es'),
            FieldPanel('feed_summary_es'),
        ),
        "Feeds"
    )

    promote_panels = [
        MultiFieldPanel(
            (
                FieldPanel('slug'),
                FieldPanel('show_in_menus'),
            ),
            "Common page configuration"
        ),
        MultiFieldPanel(
            (
                ImageChooserPanel('listings_image'),
                FieldPanel('feed_title_en'),
                FieldPanel('feed_summary_en'),
            ),
            "Feeds"
        ),
        MultiFieldPanel(
            (
                FieldPanel('seo_title'),
                FieldPanel('search_description'),
            ),
            "Search Engines"
        ),
    ]