fix optimisation with super session that may lead to integrity loss
at some point I've decided to stop ensuring ?1 cardinality was respected
when adding a new relation using a super session, to avoid the cost of
the delete query. That was yet discussable because it introduced unexpected
difference between execute and unsafe_execute, which is imo not worth it.
Also, now that rql() in migration script default to unsafe_execute, we
definitly don't want that implicit behaviour change (which already cause
bug when for instance adding another default workflow for an entity type:
without that fix we end up with *two* default workflows while the schema
tells we can have only one.
IMO we should go to the direction that super session skip all security
check, but nothing else, unless explicitly asked.
"""associate url's path to view identifier / rql queries
It currently handle url's path with the forms
* <publishing_method>
* minimal REST publishing:
* <eid>
* <etype>[/<attribute name>/<attribute value>]*
* folder navigation
You can actually control URL (more exactly path) resolution using URL path
evaluator.
XXX actionpath and folderpath execute a query whose results is lost
because of redirecting instead of direct traversal
:organization: Logilab
:copyright: 2001-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
"""
__docformat__ = "restructuredtext en"
from rql import TypeResolverException
from cubicweb import RegistryException, typed_eid
from cubicweb.web import NotFound, Redirect, component
class PathDontMatch(Exception):
"""exception used by url evaluators to notify they can't evaluate
a path
"""
class URLPublisherComponent(component.Component):
"""associate url's path to view identifier / rql queries,
by applying a chain of urlpathevaluator components.
An evaluator is a URLPathEvaluator subclass with a .evaluate_path
method taking the request object and the path to publish as
argument. It will either returns a publishing method identifier
and a rql query on success or raises a `PathDontMatch` exception
on failure. URL evaluators are called according to their `priority`
attribute, with 0 as the greatest priority and greater values as
lower priority. The first evaluator returning a result or raising
something else than `PathDontMatch` will stop the handlers chain.
"""
__regid__ = 'urlpublisher'
vreg = None # XXX necessary until property for deprecation warning is on appobject
def __init__(self, vreg, default_method='view'):
super(URLPublisherComponent, self).__init__()
self.vreg = vreg
self.default_method = default_method
evaluators = []
for evaluatorcls in vreg['components']['urlpathevaluator']:
# instantiation needed
evaluator = evaluatorcls(self)
evaluators.append(evaluator)
self.evaluators = sorted(evaluators, key=lambda x: x.priority)
def process(self, req, path):
"""given an url (essentialy caracterized by a path on the server,
but additional information may be found in the request object), return
a publishing method identifier (eg controller) and an optional result
set
:type req: `cubicweb.web.Request`
:param req: the request object
:type path: str
:param path: the path of the resource to publish
:rtype: tuple(str, `cubicweb.utils.ResultSet` or None)
:return: the publishing method identifier and an optional result set
:raise NotFound: if no handler is able to decode the given path
"""
parts = [part for part in path.split('/')
if part != ''] or (self.default_method,)
if req.form.get('rql'):
if parts[0] in self.vreg['controllers']:
return parts[0], None
return 'view', None
for evaluator in self.evaluators:
try:
pmid, rset = evaluator.evaluate_path(req, parts[:])
break
except PathDontMatch:
continue
else:
raise NotFound(path)
if pmid is None:
pmid = self.default_method
return pmid, rset
class URLPathEvaluator(component.Component):
__abstract__ = True
__regid__ = 'urlpathevaluator'
vreg = None # XXX necessary until property for deprecation warning is on appobject
def __init__(self, urlpublisher):
self.urlpublisher = urlpublisher
self.vreg = urlpublisher.vreg
class RawPathEvaluator(URLPathEvaluator):
"""handle path of the form::
<publishing_method>?parameters...
"""
priority = 0
def evaluate_path(self, req, parts):
if len(parts) == 1 and parts[0] in self.vreg['controllers']:
return parts[0], None
raise PathDontMatch()
class EidPathEvaluator(URLPathEvaluator):
"""handle path with the form::
<eid>
"""
priority = 1
def evaluate_path(self, req, parts):
if len(parts) != 1:
raise PathDontMatch()
try:
rset = req.execute('Any X WHERE X eid %(x)s',
{'x': typed_eid(parts[0])}, 'x')
except ValueError:
raise PathDontMatch()
if rset.rowcount == 0:
raise NotFound()
return None, rset
class RestPathEvaluator(URLPathEvaluator):
"""handle path with the form::
<etype>[[/<attribute name>]/<attribute value>]*
"""
priority = 2
def evaluate_path(self, req, parts):
if not (0 < len(parts) < 4):
raise PathDontMatch()
try:
etype = self.vreg.case_insensitive_etypes[parts.pop(0).lower()]
except KeyError:
raise PathDontMatch()
cls = self.vreg['etypes'].etype_class(etype)
if parts:
if len(parts) == 2:
attrname = parts.pop(0).lower()
try:
cls.e_schema.subjrels[attrname]
except KeyError:
raise PathDontMatch()
else:
attrname = cls._rest_attr_info()[0]
value = req.url_unquote(parts.pop(0))
rset = self.attr_rset(req, etype, attrname, value)
else:
rset = self.cls_rset(req, cls)
if rset.rowcount == 0:
raise NotFound()
return None, rset
def cls_rset(self, req, cls):
return req.execute(cls.fetch_rql(req.user))
def attr_rset(self, req, etype, attrname, value):
rql = u'Any X WHERE X is %s, X %s %%(x)s' % (etype, attrname)
if attrname == 'eid':
try:
rset = req.execute(rql, {'x': typed_eid(value)}, 'x')
except (ValueError, TypeResolverException):
# conflicting eid/type
raise PathDontMatch()
else:
rset = req.execute(rql, {'x': value})
return rset
class URLRewriteEvaluator(URLPathEvaluator):
"""tries to find a rewrite rule to apply
URL rewrite rule definitions are stored in URLRewriter objects
"""
priority = 3
def evaluate_path(self, req, parts):
# uri <=> req._twreq.path or req._twreq.uri
uri = req.url_unquote('/' + '/'.join(parts))
evaluators = sorted(self.vreg['urlrewriting'].all_objects(),
key=lambda x: x.priority, reverse=True)
for rewritercls in evaluators:
rewriter = rewritercls(req)
try:
# XXX we might want to chain url rewrites
return rewriter.rewrite(req, uri)
except KeyError:
continue
raise PathDontMatch()
class ActionPathEvaluator(URLPathEvaluator):
"""handle path with the form::
<any evaluator path>/<action>
"""
priority = 4
def evaluate_path(self, req, parts):
if len(parts) < 2:
raise PathDontMatch()
# remove last part and see if this is something like an actions
# if so, call
# XXX bad smell: refactor to simpler code
try:
actionsreg = self.vreg['actions']
requested = parts.pop(-1)
actions = actionsreg[requested]
except RegistryException:
raise PathDontMatch()
for evaluator in self.urlpublisher.evaluators:
if evaluator is self or evaluator.priority == 0:
continue
try:
pmid, rset = evaluator.evaluate_path(req, parts[:])
except PathDontMatch:
continue
else:
try:
action = actionsreg._select_best(actions, req, rset=rset)
except RegistryException:
continue
else:
# XXX avoid redirect
raise Redirect(action.url())
raise PathDontMatch()