Files
edx-platform/lms/askbot/skins/utils.py
Matthew Mongeau a08be52780 Skin settings.
2012-06-14 15:46:10 -04:00

196 lines
6.8 KiB
Python

"""utilities dealing with resolution of skin components
the lookup resolution process for templates and media works as follows:
* look up item in selected skin
* if not found look in 'default'
* raise an exception
"""
import os
import logging
import urllib
from django.conf import settings as django_settings
from django.utils.datastructures import SortedDict
from askbot.utils import hasher
class MediaNotFound(Exception):
"""raised when media file is not found"""
pass
def get_skins_from_dir(directory):
"""returns sorted dict with skin data, like get_available_skins
but from a specific directory
"""
skins = SortedDict()
for item in sorted(os.listdir(directory)):
item_dir = os.path.join(directory, item)
if os.path.isdir(item_dir):
skins[item] = item_dir
return skins
def get_available_skins(selected=None):
"""selected is a name of preferred skin
if it's None, then information about all skins will be returned
otherwise, only data about selected and default skins
will be returned
selected skin is guaranteed to be the first item in the dictionary
"""
skins = SortedDict()
if hasattr(django_settings, 'ASKBOT_EXTRA_SKINS_DIR'):
skins.update(get_skins_from_dir(django_settings.ASKBOT_EXTRA_SKINS_DIR))
stock_dir = os.path.normpath(os.path.dirname(__file__))
stock_skins = get_skins_from_dir(stock_dir)
default_dir = stock_skins.pop('default')
common_dir = stock_skins.pop('common')
skins.update(stock_skins)
if selected:
if selected in skins:
selected_dir = skins[selected]
skins.clear()
skins[selected] = selected_dir
else:
assert(selected == 'default' or selected == 'common')
skins = SortedDict()
#re-insert default as a last item
skins['default'] = default_dir
skins['common'] = common_dir
return skins
def get_path_to_skin(skin):
"""returns path to directory in the list of
available skin directories that contains another
directory called skin
it is assumed that all skins are named uniquely
"""
skin_dirs = get_available_skins()
return skin_dirs.get(skin, None)
def get_skin_choices():
"""returns a tuple for use as a set of
choices in the form"""
skin_names = list(reversed(get_available_skins().keys()))
return zip(skin_names, skin_names)
def resolve_skin_for_media(media=None, preferred_skin = None):
#see if file exists, if not, try skin 'default'
available_skins = get_available_skins(selected = preferred_skin).items()
for skin_name, skin_dir in available_skins:
if os.path.isfile(os.path.join(skin_dir, 'media', media)):
return skin_name
raise MediaNotFound(media)
def get_media_url(url, ignore_missing = False):
"""returns url prefixed with the skin name
of the first skin that contains the file
directories are searched in this order:
askbot_settings.ASKBOT_DEFAULT_SKIN, then 'default', then 'commmon'
if file is not found - returns None
and logs an error message
todo: move this to the skin environment class
"""
#import datetime
#before = datetime.datetime.now()
url = urllib.unquote(unicode(url))
while url[0] == '/': url = url[1:]
#a hack allowing urls media stored on external locations to
#just pass through unchanged
if url.startswith('http://') or url.startswith('https://'):
return url
#todo: handles case of multiple skin directories
#if file is in upfiles directory, then give that
url_copy = url
if url_copy.startswith(django_settings.MEDIA_URL[1:]):
file_path = url_copy.replace(
django_settings.MEDIA_URL[1:],
'',
1
)
file_path = os.path.join(
django_settings.MEDIA_ROOT,
file_path
)
if os.path.isfile(file_path):
url_copy = os.path.normpath(
'///' + url_copy
).replace(
'\\', '/'
).replace(
'///', '/'
)
return url_copy
elif ignore_missing == False:
logging.critical('missing media resource %s' % url)
#2) if it does not exist in uploaded files directory - look in skins
#purpose of this try statement is to determine
#which skin is currently used
try:
#this import statement must be hidden here
#because at startup time this branch will fail
#due to an import error
from askbot.conf import settings as askbot_settings
use_skin = askbot_settings.ASKBOT_DEFAULT_SKIN
resource_revision = askbot_settings.MEDIA_RESOURCE_REVISION
except ImportError:
use_skin = 'default'
resource_revision = None
#determine from which skin take the media file
try:
use_skin = resolve_skin_for_media(media=url, preferred_skin = use_skin)
except MediaNotFound:
if ignore_missing == False:
log_message = 'missing media resource %s in skin %s' \
% (url, use_skin)
logging.critical(log_message)
return None
url = django_settings.STATIC_URL + use_skin + '/media/' + url
url = os.path.normpath(url).replace('\\', '/')
if resource_revision:
url += '?v=%d' % resource_revision
#after = datetime.datetime.now()
#print after - before
return url
def update_media_revision(skin = None):
"""update skin media revision number based on the contents
of the skin media directory"""
from askbot.conf import settings as askbot_settings
resource_revision = askbot_settings.MEDIA_RESOURCE_REVISION
if skin:
if skin in get_skin_choices():
skin_path = get_path_to_skin(skin)
else:
raise MediaNotFound('Skin %s not found' % skin)
else:
skin = 'default'
skin_path = get_path_to_skin(askbot_settings.ASKBOT_DEFAULT_SKIN)
media_dirs = [os.path.join(skin_path, 'media'),]
if skin != 'default':
#we have default skin as parent of the custom skin
default_skin_path = get_path_to_skin('default')
media_dirs.append(os.path.join(default_skin_path, 'media'))
current_hash = hasher.get_hash_of_dirs(media_dirs)
if current_hash != askbot_settings.MEDIA_RESOURCE_REVISION_HASH:
askbot_settings.update('MEDIA_RESOURCE_REVISION', resource_revision + 1)
askbot_settings.update('MEDIA_RESOURCE_REVISION_HASH', current_hash)
logging.debug('MEDIA_RESOURCE_REVISION changed')
askbot_settings.MEDIA_RESOURCE_REVISION