Source code for cubicweb.web.application

# copyright 2003-2016 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact --
# 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 <>.
"""CubicWeb web client application object"""

import contextlib
import http.client as http_client
import json
import sys
from time import process_time, time
from contextlib import contextmanager

from rql import BadRQLQuery

from cubicweb import set_log_methods
from cubicweb import (
from cubicweb.repoapi import anonymous_cnx
from cubicweb.web import (

# make session manager available through a global variable so the debug view can
# print information about web session

def anonymized_request(req):
    from cubicweb.web.views.authentication import Session

    orig_cnx = req.cnx
    anon_cnx = anonymous_cnx(orig_cnx.repo)
        with anon_cnx:
            # web request expect a session attribute on cnx referencing the web session
            anon_cnx.session = Session(orig_cnx.repo, anon_cnx.user)
            yield req

class CookieSessionHandler:
    """a session handler using a cookie to store the session identifier"""

    def __init__(self, appli):
        self.repo = appli.repo
        self.vreg = appli.vreg
        self.session_manager = self.vreg["sessions"].select(
            "sessionmanager", repo=self.repo
        global SESSION_MANAGER
        SESSION_MANAGER = self.session_manager
        if self.vreg.config.mode != "test":
            # don't try to reset session manager during test, this leads to
            # weird failures when running multiple tests
            CW_EVENT_MANAGER.bind("after-registry-reload", self.reset_session_manager)

    def reset_session_manager(self):
        data = self.session_manager.dump_data()
        self.session_manager = self.vreg["sessions"].select(
            "sessionmanager", repo=self.repo
        global SESSION_MANAGER
        SESSION_MANAGER = self.session_manager

    def clean_sessions_interval(self):
        return self.session_manager.clean_sessions_interval

    def clean_sessions(self):
        """cleanup sessions which has not been unused since a given amount of

    def session_cookie(self, req):
        """return a string giving the name of the cookie used to store the
        session identifier.
        return "__%s_session" % self.vreg.config.appid

    def get_session(self, req):
        """Return a session object corresponding to credentials held by the req

        Session id is searched from :
        - # form variable
        - cookie

        If no session id is found, try opening a new session with credentials
        found in the request.

        Raises AuthenticationError if no session can be found or created.
        cookie = req.get_cookie()
        sessioncookie = self.session_cookie(req)
            sessionid = str(cookie[sessioncookie].value)
            session = self.get_session_by_id(req, sessionid)
        except (KeyError, InvalidSession):  # no valid session cookie
            session = self.open_session(req)
        return session

    def get_session_by_id(self, req, sessionid):
        session = self.session_manager.get_session(req, sessionid)
        session.mtime = time()
        return session

    def open_session(self, req):
        session = self.session_manager.open_session(req)
        sessioncookie = self.session_cookie(req)
        secure = req.base_url().startswith("https://")
            sessioncookie, session.sessionid, maxage=None, secure=secure, httponly=True
        if not session.anonymous_session:
            self.session_manager.postlogin(req, session)
        return session

    def logout(self, req, goto_url):
        """logout from the instance by cleaning the session and raising
        raise LogOut(url=goto_url)

    # these are overridden by set_log_methods below
    # only defining here to prevent pylint from complaining
    info = warning = error = critical = exception = debug = lambda msg, *a, **kw: None

[docs]class CubicWebPublisher: """the publisher is a singleton hold by the web frontend, and is responsible to publish HTTP request. The http server will call its main entry point ``application.handle_request``. .. automethod:: cubicweb.web.application.CubicWebPublisher.main_handle_request You have to provide both a repository and web-server config at initialization. In all in one instance both config will be the same. """ def __init__(self, repo, config, session_handler_fact=CookieSessionHandler):"starting web instance from %s", config.apphome) self.repo = repo self.vreg = repo.vreg # get instance's schema if not self.vreg.initialized: config.init_cubes(self.repo.get_cubes()) self.vreg.init_properties( self.vreg.set_schema(self.repo.get_schema()) # set the correct publish method if config["query-log-file"]: from threading import Lock self._query_log = open(config["query-log-file"], "a") self.handle_request = self.log_handle_request self._logfile_lock = Lock() else: self._query_log = None self.handle_request = self.main_handle_request # instantiate session and url resolving helpers self.session_handler = session_handler_fact(self) self.set_urlresolver() CW_EVENT_MANAGER.bind("after-registry-reload", self.set_urlresolver) def set_urlresolver(self): self.url_resolver = self.vreg["components"].select( "urlpublisher", vreg=self.vreg )
[docs] def get_session(self, req): """Return a session object corresponding to credentials held by the req May raise AuthenticationError. """ return self.session_handler.get_session(req)
# publish methods #########################################################
[docs] def log_handle_request(self, req): """wrapper around _publish to log all queries executed for a given accessed path """ def wrap_set_cnx(func): def wrap_execute(cnx): orig_execute = cnx.execute def execute(rql, kwargs=None, build_descr=True): tstart, cstart = time(), process_time() rset = orig_execute(rql, kwargs, build_descr=build_descr) cnx.executed_queries.append( (rql, kwargs, time() - tstart, process_time() - cstart) ) return rset return execute def set_cnx(cnx): func(cnx) cnx.execute = wrap_execute(cnx) cnx.executed_queries = [] return set_cnx req.set_cnx = wrap_set_cnx(req.set_cnx) tstart, cstart = time(), process_time() try: return self.main_handle_request(req) finally: cnx = req.cnx if cnx and cnx.executed_queries: with self._logfile_lock: tend, cend = time(), process_time() try: result = ["\n" + "*" * 80] result.append( "%s -- (%.3f sec, %.3f CPU sec)" % (req.url(), tend - tstart, cend - cstart) ) result += [ "%s %s -- (%.3f sec, %.3f CPU sec)" % q for q in cnx.executed_queries ] cnx.executed_queries = [] self._query_log.write("\n".join(result)) self._query_log.flush() except Exception: self.exception("error while logging queries")
[docs] def main_handle_request(self, req): """Process an HTTP request `req` :type req: `web.Request` :param req: the request object It returns the content of the http response. HTTP header and status are set on the Request object. """ if req.authmode == "http": # activate realm-based auth realm = self.vreg.config["realm"] req.set_header("WWW-Authenticate", [("Basic", {"realm": realm})], raw=False) content = b"" try: try: session = self.get_session(req) cnx = session.new_cnx() with cnx: # may need an open connection to access to e.g. properties req.set_cnx(cnx) cnx._open = None # XXX needed to reuse it a few line later :'( except AuthenticationError: # Keep the dummy session set at initialisation. such session will work to some # extend but raise an AuthenticationError on any database access. # XXX We want to clean up this approach in the future. But several cubes like # registration or forgotten password rely on this principle. @contextlib.contextmanager def dummy(): yield cnx = dummy() # nested try to allow LogOut to delegate logic to AuthenticationError # handler try: # Try to generate the actual request content with cnx: content = self.core_handle(req) # Handle user log-out except LogOut as ex: # When authentification is handled by cookie the code that # raised LogOut must has invalidated the cookie. We can just # reload the original url without authentification if self.vreg.config["auth-mode"] == "cookie" and ex.url: req.headers_out.setHeader("location", str(ex.url)) if ex.status is not None: req.status_out = http_client.SEE_OTHER # When the authentification is handled by http we must # explicitly ask for authentification to flush current http # authentification information else: # Render "logged out" content. # assignement to ``content`` prevent standard # AuthenticationError code to overwrite it. content = self.loggedout_content(req) # let the explicitly reset http credential raise AuthenticationError() except Redirect as ex: # authentication needs redirection (eg openid) content = self.redirect_handler(req, ex) # Wrong, absent or Reseted credential except AuthenticationError: # We assume here that in http auth mode the user *May* provide # Authentification Credential if asked kindly. if self.vreg.config["auth-mode"] == "http": req.status_out = http_client.UNAUTHORIZED # In the other case (coky auth) we assume that there is no way # for the user to provide them... # XXX But WHY ? else: req.status_out = http_client.FORBIDDEN # If previous error handling already generated a custom content # do not overwrite it. This is used by LogOut Except # XXX ensure we don't actually serve content if not content: content = self.need_login_content(req) assert isinstance(content, bytes) return content
[docs] def core_handle(self, req): """method called by the main publisher to process <req> relative path should return a string containing the resulting page or raise a `NotFound` exception :type req: `web.Request` :param req: the request object :rtype: str :return: the result of the pusblished url """ path = req.relative_path(False) # don't log form values they may contains sensitive information self.debug( 'publish "%s" (%s, form params: %s)', path, req.session.sessionid, list(req.form), ) # remove user callbacks on a new request (except for json controllers # to avoid callbacks being unregistered before they could be called) tstart = process_time() commited = False try: # standard processing of the request try: # The process function update the req according rewrites rules. # It stores in req._rql_rewritten if the rql comes from the endUser. ctrlid, rset = self.url_resolver.process(req, path) try: controller = self.vreg["controllers"].select( ctrlid, req, appli=self ) except NoSelectableObject: raise Unauthorized(req._("not authorized")) req.update_search_state() # In case of rewritten rql, controller.publish directly raises # notFound if the rset is empty. result = controller.publish(rset=rset) except Redirect as ex: # Redirect may be raised by edit controller when everything went # fine, so attempt to commit result = self.redirect_handler(req, ex) if req.cnx: txuuid = req.cnx.commit() commited = True if txuuid is not None:["last_undoable_transaction"] = txuuid # error case except NotFound as ex: result = self.notfound_content(req) req.status_out = ex.status except ValidationError as ex: result = self.validation_error_handler(req, ex) except RemoteCallFailed as ex: result = self.ajax_error_handler(req, ex) except Unauthorized as ex:["errmsg"] = req._( "You're not authorized to access this page. " "If you think you should, please contact the site administrator." ) req.status_out = http_client.FORBIDDEN result = self.error_handler(req, ex, tb=False) except Forbidden as ex:["errmsg"] = req._( "This action is forbidden. " "If you think it should be allowed, please contact the site administrator." ) req.status_out = http_client.FORBIDDEN result = self.error_handler(req, ex, tb=False) except (BadRQLQuery, RequestError) as ex: result = self.error_handler(req, ex, tb=False) # pass through exception except DirectResponse: if req.cnx: req.cnx.commit() raise except (AuthenticationError, LogOut): # the rollback is handled in the finally raise # Last defense line except BaseException as ex: req.status_out = http_client.INTERNAL_SERVER_ERROR result = self.error_handler(req, ex, tb=True) finally: if req.cnx and not commited: try: req.cnx.rollback() except Exception: pass # ignore rollback error at this point self.add_undo_link_to_msg(req) self.debug("query %s executed in %s sec", path, process_time() - tstart) return result
# Error handlers
[docs] def redirect_handler(self, req, ex): """handle redirect - comply to ex status - set header field - return empty content """ self.debug("redirecting to %s", str(ex.location)) req.headers_out.setHeader("location", str(ex.location)) assert 300 <= ex.status < 400 req.status_out = ex.status return b""
def validation_error_handler(self, req, ex): ex.translate(req._) # translate messages using ui language if "__errorurl" in req.form: forminfo = { "error": ex, "values": req.form, "eidmap":"eidmap", {}), }[req.form["__errorurl"]] = forminfo # XXX form session key / __error_url should be differentiated: # session key is 'url + #<form dom id', though we usually don't want # the browser to move to the form since it hides the global # messages. location = req.form["__errorurl"].rsplit("#", 1)[0] req.headers_out.setHeader("location", str(location)) req.status_out = http_client.SEE_OTHER return b"" req.status_out = http_client.CONFLICT return self.error_handler(req, ex, tb=False) def error_handler(self, req, ex, tb=False): excinfo = sys.exc_info() if tb: self.exception(repr(ex)) req.set_header("Cache-Control", "no-cache") req.remove_header("Etag") req.remove_header("Content-disposition") req.reset_message() req.reset_headers() if req.ajax_request: return self.ajax_error_handler(req, ex) try:["ex"] = ex if tb:["excinfo"] = excinfo errview = self.vreg["views"].select("error", req) template = self.main_template_id(req) content = self.vreg["views"].main_template(req, template, view=errview) except Exception: content = self.vreg["views"].main_template(req, "error-template") if isinstance(ex, PublishException) and ex.status is not None: req.status_out = ex.status return content def add_undo_link_to_msg(self, req): txuuid ="last_undoable_transaction") if txuuid is not None: msg = '<span class="undo">[<a href="{}">{}</a>]</span>'.format( req.build_url("undo", txuuid=txuuid), req._("undo"), ) req.append_to_redirect_message(msg) def ajax_error_handler(self, req, ex): req.set_header("content-type", "application/json") status = http_client.INTERNAL_SERVER_ERROR if isinstance(ex, PublishException) and ex.status is not None: status = ex.status if req.status_out < 400: # don't overwrite it if it's already set req.status_out = status json_dumper = getattr(ex, "dumps", lambda: json.dumps({"reason": str(ex)})) return json_dumper().encode("utf-8") # special case handling def need_login_content(self, req): return self.vreg["views"].main_template(req, "login") def loggedout_content(self, req): return self.vreg["views"].main_template(req, "loggedout") def notfound_content(self, req): req.form["vid"] = "404" view = self.vreg["views"].select("404", req) template = self.main_template_id(req) return self.vreg["views"].main_template(req, template, view=view) # template stuff def main_template_id(self, req): template = req.form.get("__template", req.property_value("ui.main-template")) if template not in self.vreg["views"]: template = "main-template" return template # these are overridden by set_log_methods below # only defining here to prevent pylint from complaining info = warning = error = critical = exception = debug = lambda msg, *a, **kw: None
set_log_methods(CubicWebPublisher, LOGGER) set_log_methods(CookieSessionHandler, LOGGER)