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R3600/modules/webjournal/lib/widgets/bfe_webjournal_widget_weather.py
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bfe_webjournal_widget_weather.py
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# -*- coding: utf-8 -*-
##
## This file is part of Invenio.
## Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008 CERN.
##
## Invenio 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 2 of the
## License, or (at your option) any later version.
##
## Invenio 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 Invenio; if not, write to the Free Software Foundation, Inc.,
## 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
"""
WebJournal widget - Display weather forecast
"""
import os
import time
import re
import socket
from urllib2 import urlopen
try:
# Try to load feedparser. Remember for later if it was installed
# or not. Note that feedparser is slow to load: if we don't load
# it in a 'global' way, it will be loaded for every call to this
# element.
global feedparser
import feedparser
feedparser_available = 1
except ImportError:
feedparser_available = 0
from invenio.config import \
CFG_CACHEDIR, \
CFG_ACCESS_CONTROL_LEVEL_SITE
from invenio.errorlib import register_exception
from invenio.webjournal_utils import \
parse_url_string
from invenio.messages import gettext_set_language
re_image_pattern = re.compile(r'<img\s*(class=["\']imageScale["\'])*?\s*src="(?P<image>\S*)"\s*/>',
re.DOTALL | re.IGNORECASE | re.VERBOSE)
yahoo_weather_rss_base_url = 'http://weather.yahooapis.com/forecastrss?p=%(location)s&u=%(degree_unit)s'
def format(bfo, location='SZXX0008', degree_unit='c' ,
display_weather_icon='false', weather_icon_only='false'):
"""
Display the latest weather forecast from Yahoo Weather
@param location: Yahoo location code for the forecast
@param degree_unit: Degree unit ('f'=Fahrenheit or 'c'=Celsius)
@param display_weather_icon: if 'true', display weather icon inside the forecasts
@param weather_icon_only: it 'true' display only the wheater icon (without text)
"""
if not feedparser_available:
return ""
args = parse_url_string(bfo.user_info['uri'])
journal_name = args["journal_name"]
cached_filename = "webjournal_widget_weather_%s.rss" % journal_name
expire_time_filename = "webjournal_widget_weather_%s_RSS_expires" % \
journal_name
out = get_widget_html(yahoo_weather_rss_base_url % \
{'location': location, 'degree_unit': degree_unit},
cached_filename,
expire_time_filename,
journal_name)
if weather_icon_only == 'true':
try:
out = '<img alt="" src="%s" align="bottom" />' % \
re_image_pattern.findall(out)[0][1]
except:
register_exception(req=bfo.req)
out = ''
elif display_weather_icon == 'false':
try:
out = re.sub(re_image_pattern, "", out)
except:
register_exception(req=bfo.req)
out = ''
return out
def escape_values(bfo):
"""
Called by BibFormat in order to check if output of this element
should be escaped.
"""
return 0
def get_widget_html(yahoo_weather_rss, cached_filename, expire_time_filename, journal_name):
"""
weather forecast using Yahoo! Weather service
we check and store the "expires" data from the rss feed to decide when
an update is needed.
there always resides a cached version in cds CFG_CACHEDIR along with a flat
file that indicates the time when the feed expires.
"""
cached_weather_box = _get_weather_from_cache(journal_name)
if cached_weather_box:
return cached_weather_box
# No HTML cache? Then read locally saved feed data, and even
# refresh it from Yahoo if it has expired.
try:
cached_rss_path = os.path.join(CFG_CACHEDIR, cached_filename)
assert(os.path.exists(cached_rss_path))
weather_feed = feedparser.parse(cached_rss_path)
assert(not weather_feed.bozo_exception)
except:
try:
_update_feed(yahoo_weather_rss, cached_filename, expire_time_filename)
weather_feed = feedparser.parse('%s/%s' % \
(CFG_CACHEDIR, cached_filename))
except:
return "<ul><li><i>" + _("No information available") + "</i></li></ul>"
now_in_gmt = time.gmtime()
try:
expire_time = time.strptime(open(expire_time_filename).read(),
"%a, %d %b %Y %H:%M:%S %Z")
diff = time.mktime(expire_time) - time.mktime(now_in_gmt)
except:
diff = -1
if diff < 0:
try:
_update_feed(yahoo_weather_rss, cached_filename, expire_time_filename)
weather_feed = feedparser.parse('%s/%s' % \
(CFG_CACHEDIR, cached_filename))
except:
return "<ul><li><i>" + _("No information available") + "</i></li></ul>"
# Construct the HTML. Well, simply take the one provided by
# Yahoo..
html = weather_feed.entries[0]['summary']
cache_weather(html, journal_name)
return html
def _get_weather_from_cache(journal_name):
"""
Try to get the weather information from cache. Return False if
cache does not exist
"""
cache_path = os.path.abspath('%s/webjournal/%s/weather.html' % \
(CFG_CACHEDIR,
journal_name))
if not cache_path.startswith(CFG_CACHEDIR + '/webjournal'):
# Make sure we are reading from correct directory (you
# know, in case there are '../../' inside journal name..)
return False
try:
last_update = os.path.getctime(cache_path)
except:
return False
now = time.time()
if (last_update + 15*60) < now:
# invalidate after 15 minutes
return False
try:
cached_file = open(cache_path).read()
except:
return False
return cached_file
def cache_weather(html, journal_name):
"""
Caches the weather box for 30 minutes.
"""
if not CFG_ACCESS_CONTROL_LEVEL_SITE == 2:
cache_path = os.path.abspath('%s/webjournal/%s/weather.html' % \
(CFG_CACHEDIR,
journal_name))
if cache_path.startswith(CFG_CACHEDIR + '/webjournal'):
# Do not try to cache if the journal name led us to some
# other directory ('../../' inside journal name for
# example)
cache_dir = CFG_CACHEDIR + '/webjournal/' + journal_name
if not os.path.isdir(cache_dir):
os.makedirs(cache_dir)
cache_file = file(cache_path, "w")
cache_file.write(html)
cache_file.close()
def _update_feed(yahoo_weather_rss, cached_filename, expire_time_filename):
"""
Retrieve the latest weather information from Yahoo and write it to
'cached_filename'. Also write the supposed expiration date
provided by Yahoo to 'expire_time_filename'.
"""
default_timeout = socket.getdefaulttimeout()
socket.setdefaulttimeout(2.0)
try:
try:
feed = urlopen(yahoo_weather_rss)
except:
return
finally:
socket.setdefaulttimeout(default_timeout)
cached_file = open('%s/%s' % (CFG_CACHEDIR, cached_filename), 'w')
cached_file.write(feed.read())
cached_file.close()
feed_data = feedparser.parse(yahoo_weather_rss)
expire_time = feed_data.headers['expires']
expire_file = open('%s/%s' % (CFG_CACHEDIR, expire_time_filename), 'w')
expire_file.write(expire_time)
expire_file.close()
_ = gettext_set_language('en')
dummy = _("Under the CERN sky")
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