# copyright 2003-2012 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of CubicWeb.
#
# CubicWeb is free software: you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# CubicWeb 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 Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with CubicWeb. If not, see <http://www.gnu.org/licenses/>.
"""Base class for request/session"""
__docformat__ = "restructuredtext en"
from warnings import warn
from urlparse import urlsplit, urlunsplit
from urllib import quote as urlquote, unquote as urlunquote
from datetime import time, datetime, timedelta
from cgi import parse_qs, parse_qsl
from logilab.common.decorators import cached
from logilab.common.deprecation import deprecated
from logilab.common.date import ustrftime, strptime, todate, todatetime
from rql.utils import rqlvar_maker
from cubicweb import (Unauthorized, NoSelectableObject, NoResultError,
MultipleResultsError, uilib)
from cubicweb.rset import ResultSet
ONESECOND = timedelta(0, 1, 0)
CACHE_REGISTRY = {}
class FindEntityError(Exception):
"""raised when find_one_entity() can not return one and only one entity"""
class Cache(dict):
def __init__(self):
super(Cache, self).__init__()
_now = datetime.now()
self.cache_creation_date = _now
self.latest_cache_lookup = _now
class RequestSessionBase(object):
"""base class containing stuff shared by server session and web request
request/session is the main resources accessor, mainly through it's vreg
attribute:
:attribute vreg: the instance's registry
:attribute vreg.schema: the instance's schema
:attribute vreg.config: the instance's configuration
"""
is_request = True # False for repository session
def __init__(self, vreg):
self.vreg = vreg
try:
encoding = vreg.property_value('ui.encoding')
except Exception: # no vreg or property not registered
encoding = 'utf-8'
self.encoding = encoding
# cache result of execution for (rql expr / eids),
# should be emptied on commit/rollback of the server session / web
# connection
self.user = None
self.local_perm_cache = {}
self._ = unicode
def _set_user(self, orig_user):
"""set the user for this req_session_base
A special method is needed to ensure the linked user is linked to the
connection too.
"""
# cnx validity is checked by the call to .user_info
rset = self.eid_rset(orig_user.eid, 'CWUser')
user_cls = self.vreg['etypes'].etype_class('CWUser')
user = user_cls(self, rset, row=0, groups=orig_user.groups,
properties=orig_user.properties)
user.cw_attr_cache['login'] = orig_user.login # cache login
self.user = user
self.set_entity_cache(user)
self.set_language(user.prefered_language())
def set_language(self, lang):
"""install i18n configuration for `lang` translation.
Raises :exc:`KeyError` if translation doesn't exist.
"""
self.lang = lang
gettext, pgettext = self.vreg.config.translations[lang]
# use _cw.__ to translate a message without registering it to the catalog
self._ = self.__ = gettext
self.pgettext = pgettext
def get_option_value(self, option):
raise NotImplementedError
def property_value(self, key):
"""return value of the property with the given key, giving priority to
user specific value if any, else using site value
"""
if self.user:
val = self.user.property_value(key)
if val is not None:
return val
return self.vreg.property_value(key)
def etype_rset(self, etype, size=1):
"""return a fake result set for a particular entity type"""
rset = ResultSet([('A',)]*size, '%s X' % etype,
description=[(etype,)]*size)
def get_entity(row, col=0, etype=etype, req=self, rset=rset):
return req.vreg['etypes'].etype_class(etype)(req, rset, row, col)
rset.get_entity = get_entity
rset.req = self
return rset
def eid_rset(self, eid, etype=None):
"""return a result set for the given eid without doing actual query
(we have the eid, we can suppose it exists and user has access to the
entity)
"""
eid = int(eid)
if etype is None:
etype = self.entity_metas(eid)['type']
rset = ResultSet([(eid,)], 'Any X WHERE X eid %(x)s', {'x': eid},
[(etype,)])
rset.req = self
return rset
def empty_rset(self):
""" return a guaranteed empty result """
rset = ResultSet([], 'Any X WHERE X eid -1')
rset.req = self
return rset
def entity_from_eid(self, eid, etype=None):
"""return an entity instance for the given eid. No query is done"""
try:
return self.entity_cache(eid)
except KeyError:
rset = self.eid_rset(eid, etype)
entity = rset.get_entity(0, 0)
self.set_entity_cache(entity)
return entity
def entity_cache(self, eid):
raise KeyError
def set_entity_cache(self, entity):
pass
def create_entity(self, etype, **kwargs):
"""add a new entity of the given type
Example (in a shell session):
>>> c = create_entity('Company', name=u'Logilab')
>>> create_entity('Person', firstname=u'John', surname=u'Doe',
... works_for=c)
"""
cls = self.vreg['etypes'].etype_class(etype)
return cls.cw_instantiate(self.execute, **kwargs)
@deprecated('[3.18] use find(etype, **kwargs).entities()')
def find_entities(self, etype, **kwargs):
"""find entities of the given type and attribute values.
>>> users = find_entities('CWGroup', name=u'users')
>>> groups = find_entities('CWGroup')
"""
return self.find(etype, **kwargs).entities()
@deprecated('[3.18] use find(etype, **kwargs).one()')
def find_one_entity(self, etype, **kwargs):
"""find one entity of the given type and attribute values.
raise :exc:`FindEntityError` if can not return one and only one entity.
>>> users = find_one_entity('CWGroup', name=u'users')
>>> groups = find_one_entity('CWGroup')
Exception()
"""
try:
return self.find(etype, **kwargs).one()
except (NoResultError, MultipleResultsError) as e:
raise FindEntityError("%s: (%s, %s)" % (str(e), etype, kwargs))
def find(self, etype, **kwargs):
"""find entities of the given type and attribute values.
:returns: A :class:`ResultSet`
>>> users = find('CWGroup', name=u"users").one()
>>> groups = find('CWGroup').entities()
"""
parts = ['Any X WHERE X is %s' % etype]
varmaker = rqlvar_maker(defined='X')
eschema = self.vreg.schema.eschema(etype)
for attr, value in kwargs.items():
if isinstance(value, list) or isinstance(value, tuple):
raise NotImplementedError("List of values are not supported")
if hasattr(value, 'eid'):
kwargs[attr] = value.eid
if attr.startswith('reverse_'):
attr = attr[8:]
assert attr in eschema.objrels, \
'%s not in %s object relations' % (attr, eschema)
parts.append(
'%(varname)s %(attr)s X, '
'%(varname)s eid %%(reverse_%(attr)s)s'
% {'attr': attr, 'varname': varmaker.next()})
else:
assert attr in eschema.subjrels, \
'%s not in %s subject relations' % (attr, eschema)
parts.append('X %(attr)s %%(%(attr)s)s' % {'attr': attr})
rql = ', '.join(parts)
return self.execute(rql, kwargs)
def ensure_ro_rql(self, rql):
"""raise an exception if the given rql is not a select query"""
first = rql.split(None, 1)[0].lower()
if first in ('insert', 'set', 'delete'):
raise Unauthorized(self._('only select queries are authorized'))
def get_cache(self, cachename):
"""cachename should be dotted names as in :
- cubicweb.mycache
- cubes.blog.mycache
- etc.
"""
warn.warning('[3.19] .get_cache will disappear soon. '
'Distributed caching mechanisms are being introduced instead.'
'Other caching mechanism can be used more reliably '
'to the same effect.',
DeprecationWarning)
if cachename in CACHE_REGISTRY:
cache = CACHE_REGISTRY[cachename]
else:
cache = CACHE_REGISTRY[cachename] = Cache()
_now = datetime.now()
if _now > cache.latest_cache_lookup + ONESECOND:
ecache = self.execute(
'Any C,T WHERE C is CWCache, C name %(name)s, C timestamp T',
{'name':cachename}).get_entity(0,0)
cache.latest_cache_lookup = _now
if not ecache.valid(cache.cache_creation_date):
cache.clear()
cache.cache_creation_date = _now
return cache
# url generation methods ##################################################
def build_url(self, *args, **kwargs):
"""return an absolute URL using params dictionary key/values as URL
parameters. Values are automatically URL quoted, and the
publishing method to use may be specified or will be guessed.
if ``__secure__`` argument is True, the request will try to build a
https url.
raises :exc:`ValueError` if None is found in arguments
"""
# use *args since we don't want first argument to be "anonymous" to
# avoid potential clash with kwargs
method = None
if args:
assert len(args) == 1, 'only 0 or 1 non-named-argument expected'
method = args[0]
if method is None:
method = 'view'
# XXX I (adim) think that if method is passed explicitly, we should
# not try to process it and directly call req.build_url()
base_url = kwargs.pop('base_url', None)
if base_url is None:
secure = kwargs.pop('__secure__', None)
base_url = self.base_url(secure=secure)
if '_restpath' in kwargs:
assert method == 'view', repr(method)
path = kwargs.pop('_restpath')
else:
path = method
if not kwargs:
return u'%s%s' % (base_url, path)
return u'%s%s?%s' % (base_url, path, self.build_url_params(**kwargs))
def build_url_params(self, **kwargs):
"""return encoded params to incorporate them in a URL"""
args = []
for param, values in kwargs.iteritems():
if not isinstance(values, (list, tuple)):
values = (values,)
for value in values:
assert value is not None
args.append(u'%s=%s' % (param, self.url_quote(value)))
return '&'.join(args)
def url_quote(self, value, safe=''):
"""urllib.quote is not unicode safe, use this method to do the
necessary encoding / decoding. Also it's designed to quote each
part of a url path and so the '/' character will be encoded as well.
"""
if isinstance(value, unicode):
quoted = urlquote(value.encode(self.encoding), safe=safe)
return unicode(quoted, self.encoding)
return urlquote(str(value), safe=safe)
def url_unquote(self, quoted):
"""returns a unicode unquoted string
decoding is based on `self.encoding` which is the encoding
used in `url_quote`
"""
if isinstance(quoted, unicode):
quoted = quoted.encode(self.encoding)
try:
return unicode(urlunquote(quoted), self.encoding)
except UnicodeDecodeError: # might occurs on manually typed URLs
return unicode(urlunquote(quoted), 'iso-8859-1')
def url_parse_qsl(self, querystring):
"""return a list of (key, val) found in the url quoted query string"""
if isinstance(querystring, unicode):
querystring = querystring.encode(self.encoding)
for key, val in parse_qsl(querystring):
try:
yield unicode(key, self.encoding), unicode(val, self.encoding)
except UnicodeDecodeError: # might occurs on manually typed URLs
yield unicode(key, 'iso-8859-1'), unicode(val, 'iso-8859-1')
def rebuild_url(self, url, **newparams):
"""return the given url with newparams inserted. If any new params
is already specified in the url, it's overriden by the new value
newparams may only be mono-valued.
"""
if isinstance(url, unicode):
url = url.encode(self.encoding)
schema, netloc, path, query, fragment = urlsplit(url)
query = parse_qs(query)
# sort for testing predictability
for key, val in sorted(newparams.iteritems()):
query[key] = (self.url_quote(val),)
query = '&'.join(u'%s=%s' % (param, value)
for param, values in query.items()
for value in values)
return urlunsplit((schema, netloc, path, query, fragment))
# bound user related methods ###############################################
@cached
def user_data(self):
"""returns a dictionary with this user's information.
The keys are :
login
The user login
name
The user name, returned by user.name()
email
The user principal email
"""
userinfo = {}
user = self.user
userinfo['login'] = user.login
userinfo['name'] = user.name()
userinfo['email'] = user.cw_adapt_to('IEmailable').get_email()
return userinfo
# formating methods #######################################################
def view(self, __vid, rset=None, __fallback_oid=None, __registry='views',
initargs=None, w=None, **kwargs):
"""Select object with the given id (`__oid`) then render it. If the
object isn't selectable, try to select fallback object if
`__fallback_oid` is specified.
If specified `initargs` is expected to be a dictionary containing
arguments that should be given to selection (hence to object's __init__
as well), but not to render(). Other arbitrary keyword arguments will be
given to selection *and* to render(), and so should be handled by
object's call or cell_call method..
"""
if initargs is None:
initargs = kwargs
else:
initargs.update(kwargs)
try:
view = self.vreg[__registry].select(__vid, self, rset=rset, **initargs)
except NoSelectableObject:
if __fallback_oid is None:
raise
view = self.vreg[__registry].select(__fallback_oid, self,
rset=rset, **initargs)
return view.render(w=w, **kwargs)
def printable_value(self, attrtype, value, props=None, displaytime=True,
formatters=uilib.PRINTERS):
"""return a displayablye value (i.e. unicode string)"""
if value is None:
return u''
try:
as_string = formatters[attrtype]
except KeyError:
self.error('given bad attrtype %s', attrtype)
return unicode(value)
return as_string(value, self, props, displaytime)
def format_date(self, date, date_format=None, time=False):
"""return a string for a date time according to instance's
configuration
"""
if date is not None:
if date_format is None:
if time:
date_format = self.property_value('ui.datetime-format')
else:
date_format = self.property_value('ui.date-format')
return ustrftime(date, date_format)
return u''
def format_time(self, time):
"""return a string for a time according to instance's
configuration
"""
if time is not None:
return ustrftime(time, self.property_value('ui.time-format'))
return u''
def format_float(self, num):
"""return a string for floating point number according to instance's
configuration
"""
if num is not None:
return self.property_value('ui.float-format') % num
return u''
def parse_datetime(self, value, etype='Datetime'):
"""get a datetime or time from a string (according to etype)
Datetime formatted as Date are accepted
"""
assert etype in ('Datetime', 'Date', 'Time'), etype
# XXX raise proper validation error
if etype == 'Datetime':
format = self.property_value('ui.datetime-format')
try:
return todatetime(strptime(value, format))
except ValueError:
pass
elif etype == 'Time':
format = self.property_value('ui.time-format')
try:
# (adim) I can't find a way to parse a Time with a custom format
date = strptime(value, format) # this returns a DateTime
return time(date.hour, date.minute, date.second)
except ValueError:
raise ValueError(self._('can\'t parse %(value)r (expected %(format)s)')
% {'value': value, 'format': format})
try:
format = self.property_value('ui.date-format')
dt = strptime(value, format)
if etype == 'Datetime':
return todatetime(dt)
return todate(dt)
except ValueError:
raise ValueError(self._('can\'t parse %(value)r (expected %(format)s)')
% {'value': value, 'format': format})
def _base_url(self, secure=None):
if secure:
return self.vreg.config.get('https-url') or self.vreg.config['base-url']
return self.vreg.config['base-url']
def base_url(self, secure=None):
"""return the root url of the instance
"""
url = self._base_url(secure=secure)
return url if url is None else url.rstrip('/') + '/'
# abstract methods to override according to the web front-end #############
def describe(self, eid, asdict=False):
"""return a tuple (type, sourceuri, extid) for the entity with id <eid>"""
raise NotImplementedError