A Django template tag decorator for including a dynamically set template with context variables

dynamic_inclusion_tag.py

from functools import wraps
from inspect import getfullargspec, unwrap

from django import template

register = template.Library()


def dynamic_inclusion_tag(filename=None, func=None, takes_context=None, name=None):
    """
    Register a callable as an inclusion tag:

    @dynamic_inclusion_tag("results.html")
    def show_results(poll, *args, **kwargs):
        choices = poll.choice_set.all()
        return {"choices": choices}

    @dynamic_inclusion_tag("results.html", takes_context=True)
    def show_results(context, poll, *args, **kwargs):
        choices = poll.choice_set.all()
        return {"choices": choices}

    Then use it in the template as following:
    {% show_results poll %}
    {% show_results poll using "poll_results.html" %}
    """

    def decorator(func):
        (
            params,
            varargs,
            varkw,
            defaults,
            kwonly,
            kwonly_defaults,
            _,
        ) = getfullargspec(unwrap(func))
        function_name = name or func.__name__

        @wraps(func)
        def compile_func(parser, token):
            bits = token.split_contents()
            tag_name = bits[0]
            bits = bits[1:]
            args, kwargs = template.library.parse_bits(
                parser,
                bits,
                params,
                varargs,
                varkw,
                defaults,
                kwonly,
                kwonly_defaults,
                takes_context,
                function_name,
            )
            template_name = filename

            if len(bits) >= 2 and bits[-2] == "using":
                template_name = bits[-1][1:-1]  # Remove quotes

            if not template_name:
                raise template.TemplateSyntaxError(
                    f"{tag_name} tag requires a template name to be specified "
                    f"either in the decorator or using 'using' keyword."
                )

            return template.library.InclusionNode(
                func=func,
                takes_context=takes_context,
                args=args,
                kwargs=kwargs,
                filename=template_name,
            )

        register.tag(function_name, compile_func)
        return func

    return decorator