Jinja2

[fjbardelli]

Is posible edit jinja2 templete?

[nad2000]

@fjbardelli, it can be done using Jijna2 environment, that sets up by the Jinja2 engine (https://github.com/django/django/blob/main/django/template/backends/jinja2.py#L28), replacing the loader it sets up by default with Jinja2 ChoiceLoader using environment setting function according to https://docs.djangoproject.com/en/5.1/topics/templates/#django.template.backends.jinja2.Jinja2, for example (the Jinja2 environment module of your application, eg, jinja2_env.py):

def environment(loader=None, **options):
    if loader:
        options["loader"] = ChoiceLoader(
            [
                loader,
                DbLoader(),
            ]
        )

    env = Environment(**options)
    env.globals.update(
        {
            "get_messages": messages.get_messages,
            "crispy": crispy,
            "static": static,
            "url": lambda viewname, urlconf=None, current_app=None, *args, **kwargs: reverse(
                viewname=viewname,
                urlconf=urlconf,
                args=args or None,
                kwargs=kwargs or None,
                current_app=current_app,
            ),
        }
    )
    env.filters["basename"] = basename
    env.install_gettext_translations(translation)
    return env

where DbLoader is a Jinja2 loader that loads the templates from dbteplates:

...
from jinja2 import Environment, pass_context, BaseLoader, TemplateNotFound, ChoiceLoader
from dbtemplates.models import Template


class DbLoader(BaseLoader):

    def get_source(self, environment, template):
        # site = Site.objects.get_current()
        # site_id = site and site.pk
        site_id = settings.SITE_ID.site_id  # if it uses 'django-multisite'
        t = (
            Template.objects.filter(
                Q(name__exact=template), Q(sites__pk=site_id) | Q(sites__isnull=True)
            )
            .order_by("-sites__pk")
            .first()
        )
        if not t:
            raise TemplateNotFound(template)
        lc = t.last_changed
        pk = t.pk
        breakpoint()
        return (
            t.content,
            f"{template}::{pk}::{site_id}",
            lambda: not (Template.objects.filter(pk=pk, last_changed__gt=lc).exists()),  # TODO: ???
        )

I reckon it might be possible to improve performance by using the dbtemplates cache instead of a DB lookup for testing if the template was updated.

And the application config:

TEMPLATES = [
    {
        # https://docs.djangoproject.com/en/dev/ref/settings/#std:setting-TEMPLATES-BACKEND
        "BACKEND": "django.template.backends.django.DjangoTemplates",
        ....
    },
    {
        "BACKEND": "django.template.backends.jinja2.Jinja2",
        "DIRS": [str(APPS_DIR / "jinja2")],
        "APP_DIRS": True,
        "OPTIONS": {
            "environment": "jinja2_env.environment",
            "extensions": ["jinja2.ext.i18n"],
        },
    },
]

That should work and search for Jinja2 templates if it fails to find the template in the filesystem.

[fjbardelli]

Thank you very much for the answer