# (c) 2005 Ian Bicking and contributors; written for Paste (http://pythonpaste.org)
# Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php
"""
WSGI middleware
Captures any exceptions and prints a pretty report. See the `cgitb
documentation `_
for more.
"""
import cgitb
from cStringIO import StringIO
import sys
from paste.util import converters
class NoDefault(object):
pass
class CgitbMiddleware(object):
def __init__(self, app,
global_conf=None,
display=NoDefault,
logdir=None,
context=5,
format="html"):
self.app = app
if global_conf is None:
global_conf = {}
if display is NoDefault:
display = global_conf.get('debug')
if isinstance(display, basestring):
display = converters.asbool(display)
self.display = display
self.logdir = logdir
self.context = int(context)
self.format = format
def __call__(self, environ, start_response):
try:
app_iter = self.app(environ, start_response)
return self.catching_iter(app_iter, environ)
except:
exc_info = sys.exc_info()
start_response('500 Internal Server Error',
[('content-type', 'text/html')],
exc_info)
response = self.exception_handler(exc_info, environ)
return [response]
def catching_iter(self, app_iter, environ):
if not app_iter:
raise StopIteration
error_on_close = False
try:
for v in app_iter:
yield v
if hasattr(app_iter, 'close'):
error_on_close = True
app_iter.close()
except:
response = self.exception_handler(sys.exc_info(), environ)
if not error_on_close and hasattr(app_iter, 'close'):
try:
app_iter.close()
except:
close_response = self.exception_handler(
sys.exc_info(), environ)
response += (
'
Error in .close():
%s'
% close_response)
yield response
def exception_handler(self, exc_info, environ):
dummy_file = StringIO()
hook = cgitb.Hook(file=dummy_file,
display=self.display,
logdir=self.logdir,
context=self.context,
format=self.format)
hook(*exc_info)
return dummy_file.getvalue()
def make_cgitb_middleware(app, global_conf,
display=NoDefault,
logdir=None,
context=5,
format='html'):
"""
Wraps the application in the ``cgitb`` (standard library)
error catcher.
display:
If true (or debug is set in the global configuration)
then the traceback will be displayed in the browser
logdir:
Writes logs of all errors in that directory
context:
Number of lines of context to show around each line of
source code
"""
from paste.deploy.converters import asbool
if display is not NoDefault:
display = asbool(display)
if 'debug' in global_conf:
global_conf['debug'] = asbool(global_conf['debug'])
return CgitbMiddleware(
app, global_conf=global_conf,
display=display,
logdir=logdir,
context=context,
format=format)