Jinja2 loaders for django 1.2

jinja2_loaders.py

from coffin.template import Template as JTemplate
from django.template.loaders import app_directories, filesystem
from django.template import TemplateDoesNotExist

# integrate jinja instead of django template language to take advantage of 
# all django helper function like direct_to_template

def _render_or_die(source, origin):
    """helper function for loaders below. Makes a simple check if 
    passed template seems to be jinja one and raising exception otherwise"""
    
    if 'jinja' in origin:
        # TODO: integration with debug_toolbar
        return JTemplate(source)
    else:
        # This will cause django to try next loader in list
        raise TemplateDoesNotExist('Not a jinja template')
    

class AppDirsLoader(app_directories.Loader):
    """Very simple implementation of the django app_directories loader for jinja"""
    is_usable = True

    def load_template(self, template_name, template_dirs=None):
        source, origin = self.load_template_source(template_name, template_dirs)
        
        return _render_or_die(source, origin), origin
        
class FileSystemLoader(filesystem.Loader):
    """Very simple implementation of the django filesystem loader for jinja"""
    is_usable = True

    def load_template(self, template_name, template_dirs=None):
        source, origin = self.load_template_source(template_name, template_dirs)
        
        return _render_or_die(source, origin), origin