Use a tween application instead of a catchall route.
Using a catchall route has some drawbacks. Especially, we have no mean to have
a route that would match only if no other one does AND no view matches either.
Said differently, our default handler cannot be plugged on the route level nor
the view level, because it is has to be activated only if nothing else works in
the pyramid application.
Using a tween application allow to handle requests that raises a HTTPNotFound
error, while having the pyramid error handler still active between our tween
app and the outside world.
Related to #4291173
from pyramid import security
from pyramid import tweens
from pyramid.httpexceptions import HTTPSeeOther
from pyramid import httpexceptions
import cubicweb
import cubicweb.web
from cubicweb.web.application import CubicWebPublisher
from cubicweb.web import LogOut, cors
from pyramid_cubicweb.core import cw_to_pyramid
class PyramidSessionHandler(object):
"""A CW Session handler that rely on the pyramid API to fetch the needed
informations"""
def __init__(self, appli):
self.appli = appli
def get_session(self, req):
return req._request.cw_session
def logout(self, req, goto_url):
raise LogOut(url=goto_url)
class CubicWebPyramidHandler(object):
def __init__(self, appli):
self.appli = appli
def __call__(self, request):
"""
Handler that mimics what CubicWebPublisher.main_handle_request and
CubicWebPublisher.core_handle do
"""
# XXX The main handler of CW forbid anonymous https connections
# I guess we can drop this "feature" but in doubt I leave this comment
# so we don't forget about it. (cdevienne)
req = request.cw_request
vreg = request.registry['cubicweb.registry']
try:
try:
with cw_to_pyramid(request):
cors.process_request(req, vreg.config)
ctrlid, rset = self.appli.url_resolver.process(req, req.path)
try:
controller = vreg['controllers'].select(
ctrlid, req, appli=self.appli)
except cubicweb.NoSelectableObject:
raise httpexceptions.HTTPUnauthorized(
req._('not authorized'))
req.update_search_state()
content = controller.publish(rset=rset)
# XXX this auto-commit should be handled by the cw_request cleanup
# or the pyramid transaction manager.
# It is kept here to have the ValidationError handling bw
# compatible
if req.cnx:
txuuid = req.cnx.commit()
# commited = True
if txuuid is not None:
req.data['last_undoable_transaction'] = txuuid
except cors.CORSPreflight:
request.response.status_int = 200
except cubicweb.web.ValidationError as ex:
# XXX The validation_error_handler implementation is light, we
# should redo it better in cw_to_pyramid, so it can be properly
# handled when raised from a cubicweb view.
# BUT the real handling of validation errors should be done
# earlier in the controllers, not here. In the end, the
# ValidationError should never by handled here.
content = self.appli.validation_error_handler(req, ex)
except cubicweb.web.RemoteCallFailed as ex:
# XXX The default pyramid error handler (or one that we provide
# for this exception) should be enough
# content = self.appli.ajax_error_handler(req, ex)
raise
if content is not None:
request.response.body = content
# XXX CubicWebPyramidRequest.headers_out should
# access directly the pyramid response headers.
request.response.headers.clear()
for k, v in req.headers_out.getAllRawHeaders():
for item in v:
request.response.headers.add(k, item)
except LogOut as ex:
# The actual 'logging out' logic should be in separated function
# that is accessible by the pyramid views
headers = security.forget(request)
raise HTTPSeeOther(ex.url, headers=headers)
# except AuthenticationError:
# XXX I don't think it makes sens to catch this ex here (cdevienne)
return request.response
class TweenHandler(object):
def __init__(self, handler, registry):
self.handler = handler
self.cwhandler = registry['cubicweb.handler']
def __call__(self, request):
try:
response = self.handler(request)
except httpexceptions.HTTPNotFound:
response = self.cwhandler(request)
return response
def includeme(config):
# Set up a tween app that will handle the request if the main application
# raises a HTTPNotFound exception.
# This is to keep legacy compatibility for cubes that makes use of the
# cubicweb controllers.
cwconfig = config.registry['cubicweb.config']
repository = config.registry['cubicweb.repository']
cwappli = CubicWebPublisher(
repository, cwconfig,
session_handler_fact=PyramidSessionHandler)
cwhandler = CubicWebPyramidHandler(cwappli)
config.registry['cubicweb.appli'] = cwappli
config.registry['cubicweb.handler'] = cwhandler
config.add_tween(
'pyramid_cubicweb.bwcompat.TweenHandler', under=tweens.EXCVIEW)