weboob-devel/weboob/tools/browser2/browser.py
2014-03-10 13:11:06 +01:00

284 lines
9.3 KiB
Python

# -*- coding: utf-8 -*-
# Copyright(C) 2012 Laurent Bachelier
#
# This file is part of weboob.
#
# weboob 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 of the License, or
# (at your option) any later version.
#
# weboob 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with weboob. If not, see <http://www.gnu.org/licenses/>.
from __future__ import absolute_import
import urlparse
import requests
from requests.status_codes import codes
# TODO define __all__
class Profile(object):
"""
A profile represents the way Browser should act.
Usually it is to mimic a real browser.
"""
def setup_session(self, session):
"""
Change default headers, set up hooks, etc.
Warning: Do not enable lzma, bzip or bzip2, sdch encodings
as python-requests does not support it yet.
In doubt, do not change the default Accept-Encoding header
of python-requests.
"""
raise NotImplementedError()
class Weboob(Profile):
"""
It's us!
Recommended for Weboob-friendly websites only.
"""
def __init__(self, version):
self.version = version
def setup_session(self, session):
session.config['base_headers']['User-Agent'] = 'weboob/%s' % self.version
class Firefox(Profile):
"""
Try to mimic a specific version of Firefox.
Ideally, it should follow the current ESR Firefox:
https://www.mozilla.org/en-US/firefox/organizations/all.html
Do not change the Firefox version without changing the Gecko one!
"""
def setup_session(self, session):
"""
Set up headers for a standard Firefox request
(except for DNT which isn't on by default but is a good idea).
The goal is to be unidentifiable.
"""
# Replace all base requests headers
# https://developer.mozilla.org/en/Gecko_user_agent_string_reference
# https://bugzilla.mozilla.org/show_bug.cgi?id=572650
session.config['base_headers'] = {'Accept-Language': 'en-us,en;q=0.5',
'Accept-Encoding': 'gzip, deflate',
'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:10.0.3) Gecko/20100101 Firefox/10.0.3',
'DNT': '1'}
# It also has "Connection: Keep-Alive", that should only be added this way:
session.config['keep_alive'] = True
class Wget(Profile):
"""
Common alternative user agent.
Some websites will give you a version with less JavaScript.
Some others could ban you (after all, wget is not a real browser).
"""
def __init__(self, version='1.11.4'):
self.version = version
def setup_session(self, session):
# Don't remove base headers, if websites want to block fake browsers,
# they will probably block any wget user agent anyway.
session.config['base_headers'].update({'Accept': '*/*',
'User-Agent': 'Wget/%s' % self.version})
session.config['keep_alive'] = True
class BaseBrowser(object):
"""
Simple browser class.
Act like a browser, and don't try to do too much.
"""
PROFILE = Firefox()
TIMEOUT = 10.0
def __init__(self):
profile = self.PROFILE
self._setup_session(profile)
self.url = None
self.response = None
def _setup_session(self, profile):
"""
Set up a python-requests session for our usage.
"""
session = requests.Session()
# Raise exceptions on HTTP errors
session.config['safe_mode'] = False
session.config['danger_mode'] = True
# TODO max_retries?
# TODO connect config['verbose'] to our logger
# TODO find a way to have multiple session hooks
# lists don't work in this context
session.hooks['response'] = self._fix_redirect
profile.setup_session(session)
self.session = session
def _fix_redirect(self, response):
"""
TL;DR: Web browsers and web developers suck.
Most browsers do not follow the RFC for HTTP 302
but python-requests does.
And web developers assume we don't follow it either:
https://en.wikipedia.org/wiki/Post/Redirect/Get
Gets a Response, and returns a new Response.
Used as a 'response' hook for python-requests.
This is a hack, it would be better as an option in python-requests.
What we do is run again the response building,
but this time with allow_redirects=True, and if we have a HTTP 302,
we set a temporary fake method='GET' and empty data.
So in order to have proper allow_redirects=True handling of POSTs
you have to create a request with allow_redirects=False,
and fix-redirect=True in config (which is for the first one the
python-requests default for POSTs, and for the second one the
BaseBrowser default).
"""
request = response.request
# If the request wasn't redirected, and is a redirection,
# and we allowed it to be fixed,
# restart the request building, but with a changed action.
if request.allow_redirects is False \
and request.response.status_code in requests.models.REDIRECT_STATI \
and request.config.get('fix-redirect'):
if request.response.status_code is codes.found:
# force the next request to be GET
real_method = request.method
request.method = 'GET'
real_data = request.data
request.data = None
# build the response again
request.allow_redirects = True
request._build_response(response.raw)
if request.response.status_code is codes.found:
# restore info
request.method = real_method
request.data = real_data
return request.response
def location(self, url, data=None, fix_redirect=True, **kwargs):
"""
Like open() but also changes the current URL and response.
This is the most common method to request web pages.
"""
response = self.open(url, data, fix_redirect, **kwargs)
self.response = response
self.url = self.response.url
return response
def open(self, url, data=None, fix_redirect=True, **kwargs):
"""
Wrapper around request().
Makes a GET request, or a POST if data is not None.
An empty data *will* make a post.
Call this if you do not want to "visit" the URL (for instance, you
are downloading a file).
:param url: URL
:type url: str
:rtype: :class:`requests.Response`
"""
method = kwargs.pop('method', None)
if method is None:
if data is None:
method = 'GET'
else:
method = 'POST'
kwargs['data'] = data
if fix_redirect:
kwargs.setdefault('config', {}).setdefault('fix-redirect', True)
response = self.request(method, url, **kwargs)
return response
def request(self, *args, **kwargs):
"""
Creates a Request object and calls it.
Takes the sames arguments as request.request()
Returns a Response object.
Most of the time, you should use location() or open().
"""
# python-requests or urllib3 does not handle
# empty POST requests properly, so some websites refuse it.
data = kwargs.get('data')
if data is not None and len(data) == 0:
kwargs.setdefault('headers', {}).setdefault('Content-Length', '0')
kwargs.setdefault('timeout', self.TIMEOUT)
return self.session.request(*args, **kwargs)
class DomainBrowser(BaseBrowser):
"""
A browser that handles relative URLs and can have a base URL (usually a domain).
For instance self.location('/hello') will get http://weboob.org/hello
if BASEURL is 'http://weboob.org/'.
"""
BASEURL = None
"""
Base URL, e.g. 'http://weboob.org/' or 'https://weboob.org/'
See absurl().
"""
def absurl(self, uri, base=None):
"""
Get the absolute URL, relative to the base URL.
If BASEURL is None, it will try to use the current URL.
If base is False, it will always try to use the current URL.
:param uri: URI to make absolute. It can be already absolute.
:type uri: str
:param base: Base absolute URL.
:type base: str or None or False
:rtype: str
"""
if base is None:
base = self.BASEURL
if base is None or base is False:
base = self.url
return urlparse.urljoin(base, uri)
def open(self, uri, *args, **kwargs):
return BaseBrowser.open(self, self.absurl(uri), *args, **kwargs)
def home(self):
"""
Go to the "home" page, usually the BASEURL.
"""
return self.location(self.BASEURL or self.absurl('/'))