qutebrowser/qutebrowser/utils/jinja.py
Florian Bruhin 3179e8c7b9 Always autoescape jinja environments unless overridden
We were only rendering .html files before, so the old _guess_autoescape function
had the effect of always autoescaping .render() (from a file) but never
autoescaping .from_string(). However, most places using .from_string() actually
render (Qt-)HTML via jinja, so they should escape stuff!

Now, we always autoescape, except when the caller uses the
jinja.environment.no_autoescape() context manager, which places rendering
stylesheets now do.

This impacted:

- Confirm quit texts (no HTML here)
- config.py loading errors
  (where this was found because of an error containing - a <keybinding>)
- Certificate error prompts
  (should be fine from what I can tell, as the only user-controllable output is
  the hostname, which cannot contain HTML)
2017-09-16 10:43:59 +02:00

139 lines
4.3 KiB
Python

# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:
# Copyright 2014-2017 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
#
# This file is part of qutebrowser.
#
# qutebrowser is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# qutebrowser 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 qutebrowser. If not, see <http://www.gnu.org/licenses/>.
"""Utilities related to jinja2."""
import os
import os.path
import contextlib
import traceback
import mimetypes
import html
import jinja2
import jinja2.exceptions
from qutebrowser.utils import utils, urlutils, log
from PyQt5.QtCore import QUrl
html_fallback = """
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Error while loading template</title>
</head>
<body>
<p><span style="font-size:120%;color:red">
The %FILE% template could not be found!<br>
Please check your qutebrowser installation
</span><br>
%ERROR%
</p>
</body>
</html>
"""
class Loader(jinja2.BaseLoader):
"""Jinja loader which uses utils.read_file to load templates.
Attributes:
_subdir: The subdirectory to find templates in.
"""
def __init__(self, subdir):
self._subdir = subdir
def get_source(self, _env, template):
path = os.path.join(self._subdir, template)
try:
source = utils.read_file(path)
except OSError as e:
source = html_fallback.replace("%ERROR%", html.escape(str(e)))
source = source.replace("%FILE%", html.escape(template))
log.misc.exception("The {} template could not be loaded from {}"
.format(template, path))
# Currently we don't implement auto-reloading, so we always return True
# for up-to-date.
return source, path, lambda: True
class Environment(jinja2.Environment):
"""Our own jinja environment which is more strict."""
def __init__(self):
super().__init__(loader=Loader('html'),
autoescape=lambda _name: self._autoescape,
undefined=jinja2.StrictUndefined)
self.globals['resource_url'] = self._resource_url
self.globals['file_url'] = urlutils.file_url
self.globals['data_url'] = self._data_url
self._autoescape = True
@contextlib.contextmanager
def no_autoescape(self):
"""Context manager to temporarily turn off autoescaping."""
self._autoescape = False
yield
self._autoescape = True
def _resource_url(self, path):
"""Load images from a relative path (to qutebrowser).
Arguments:
path: The relative path to the image
"""
image = utils.resource_filename(path)
return QUrl.fromLocalFile(image).toString(QUrl.FullyEncoded)
def _data_url(self, path):
"""Get a data: url for the broken qutebrowser logo."""
data = utils.read_file(path, binary=True)
filename = utils.resource_filename(path)
mimetype = mimetypes.guess_type(filename)
assert mimetype is not None, path
return urlutils.data_url(mimetype[0], data).toString()
def getattr(self, obj, attribute):
"""Override jinja's getattr() to be less clever.
This means it doesn't fall back to __getitem__, and it doesn't hide
AttributeError.
"""
return getattr(obj, attribute)
def render(template, **kwargs):
"""Render the given template and pass the given arguments to it."""
try:
return environment.get_template(template).render(**kwargs)
except jinja2.exceptions.UndefinedError:
log.misc.exception("UndefinedError while rendering " + template)
err_path = os.path.join('html', 'undef_error.html')
err_template = utils.read_file(err_path)
tb = traceback.format_exc()
return err_template.format(pagename=template, traceback=tb)
environment = Environment()