"""

Wrapper for loading templates from the filesystem.

"""

from django.conf import settings

from django.template import TemplateDoesNotExist

from django.utils._os import safe_join

def get_template_sources(template_name, template_dirs=None):

    if not template_dirs:

        template_dirs = settings.TEMPLATE_DIRS

    for template_dir in template_dirs:

        try:

            yield safe_join(template_dir, template_name)

        except ValueError:

            # The joined path was located outside of template_dir.

            pass

def load_template_source(template_name, template_dirs=None):

    tried = []

    for filepath in get_template_sources(template_name, template_dirs):

        try:

            return (open(filepath).read().decode(settings.FILE_CHARSET), filepath)

        except IOError:

            tried.append(filepath)

    if tried:

        error_msg = "Tried %s" % tried

    else:

        error_msg = "Your TEMPLATE_DIRS setting is empty. Change it to point to at least one template directory."

    raise TemplateDoesNotExist, error_msg

load_template_source.is_usable = True