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##
# This file is part of TALER
# (C) 2017 INRIA
#
# TALER is free software; you can redistribute it and/or
# modify it under the terms of the GNU Affero General Public
# License as published by the Free Software Foundation; either
# version 3, or (at your option) any later version.
#
# TALER is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty
# of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public
# License along with TALER; see the file COPYING. If not,
# see <http://www.gnu.org/licenses/>
#
# @author Florian Dold
# @brief Extends the Jinja2 API with custom functions.
import os
from urllib.parse import urlparse
from django.urls import reverse, get_script_prefix
from django.conf import settings
from jinja2 import Environment
##
# Check if a URL is absolute or not.
#
# @param urloc the URL to check.
# @return True if the URL is absolute, False otherwise.
def is_absolute(urloc):
return bool(urlparse(urloc).netloc)
##
# Join URL components held in a list, taking care
# of not having double slashes in the result.
#
# @param parts list of URL components.
# @return the string made of the joined components
def join_urlparts(*parts):
ret = ""
part = 0
while part < len(parts):
buf = parts[part]
part += 1
if ret.endswith("/"):
buf = buf.lstrip("/")
elif ret and not buf.startswith("/"):
buf = "/" + buf
ret += buf
return ret
##
# Prefixes the argument with the location for static content.
#
# @param urloc the URL portion that should be prefixed; in
# other words, this will be in final position in the
# produced result.
# @return the URL that picks @a urloc from the location for
# static content.
def static(urloc):
if is_absolute(urloc):
return urloc
return join_urlparts(get_script_prefix(), settings.STATIC_URL, urloc)
##
# Helper function that fetches a value from the settings.
#
# @param name the name to lookup in the settings.
# @return @a name's value as defined in the settings, or
# a empty string otherwise.
def settings_value(name):
return getattr(settings, name, "")
##
# Fetch the URL given its "name".
#
# @param url_name URL's name as defined in urlargs.py
# @param kwargs key-value list that will be appended
# to the URL as the parameter=value pairs.
def url(url_name, **kwargs):
# strangely, Django's 'reverse' function
# takes a named parameter 'kwargs' instead
# of real kwargs.
return reverse(url_name, kwargs=kwargs)
##
# Helper function that reads a value from the environment.
#
# @param name env value to read
# @return the value, or None if not found.
def env_get(name, default=None):
return os.environ.get(name, default)
##
# Jinja2 specific function used to activate the definitions
# of this module.
#
# @param options opaque argument (?) given from the caller.
# @return Jinja2-specific object that contains the new definitions.
def environment(**options):
env = Environment(**options)
env.globals.update({
'static': static,
'url': url,
'settings_value': settings_value,
'env': env_get,
})
return env
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