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# IVLE - Informatics Virtual Learning Environment
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# Copyright (C) 2007-2008 The University of Melbourne
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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# Presents a CGIRequest class which creates an object compatible with IVLE
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# Request objects (the same interface exposed by www.dispatch.request) from a
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# This allows CGI scripts to create request objects and then pass them to
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# normal IVLE handlers.
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# NOTE: This object does not support write_html_head_foot (simply because we
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# do not need it in its intended application: fileservice).
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def _http_headers_in_from_cgi():
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"""Returns a dictionary of HTTP headers and their values, reading from the
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for k in os.environ.keys():
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if k.startswith("HTTP_"):
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# Change the case - underscores become - and each word is
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varname = '-'.join(map(lambda x: x[0:1] + x[1:].lower(),
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d[varname] = os.environ[k]
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"""An IVLE request object, built from a CGI script. This is presented to
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the IVLE apps as a way of interacting with the CGI server.
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See dispatch.request for a full interface specification.
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# COPIED from dispatch/request.py
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# Special code for an OK response.
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# Do not use HTTP_OK; for some reason Apache produces an "OK" error
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# message if you do that.
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HTTP_SWITCHING_PROTOCOLS = 101
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HTTP_NON_AUTHORITATIVE = 203
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HTTP_RESET_CONTENT = 205
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HTTP_PARTIAL_CONTENT = 206
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HTTP_MULTI_STATUS = 207
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HTTP_MULTIPLE_CHOICES = 300
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HTTP_MOVED_PERMANENTLY = 301
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HTTP_MOVED_TEMPORARILY = 302
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HTTP_NOT_MODIFIED = 304
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HTTP_TEMPORARY_REDIRECT = 307
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HTTP_BAD_REQUEST = 400
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HTTP_UNAUTHORIZED = 401
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HTTP_PAYMENT_REQUIRED = 402
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HTTP_METHOD_NOT_ALLOWED = 405
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HTTP_NOT_ACCEPTABLE = 406
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HTTP_PROXY_AUTHENTICATION_REQUIRED= 407
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HTTP_REQUEST_TIME_OUT = 408
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HTTP_LENGTH_REQUIRED = 411
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HTTP_PRECONDITION_FAILED = 412
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HTTP_REQUEST_ENTITY_TOO_LARGE = 413
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HTTP_REQUEST_URI_TOO_LARGE = 414
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HTTP_UNSUPPORTED_MEDIA_TYPE = 415
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HTTP_RANGE_NOT_SATISFIABLE = 416
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HTTP_EXPECTATION_FAILED = 417
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HTTP_UNPROCESSABLE_ENTITY = 422
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HTTP_FAILED_DEPENDENCY = 424
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HTTP_INTERNAL_SERVER_ERROR = 500
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HTTP_NOT_IMPLEMENTED = 501
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HTTP_BAD_GATEWAY = 502
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HTTP_SERVICE_UNAVAILABLE = 503
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HTTP_GATEWAY_TIME_OUT = 504
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HTTP_VERSION_NOT_SUPPORTED = 505
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HTTP_VARIANT_ALSO_VARIES = 506
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HTTP_INSUFFICIENT_STORAGE = 507
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HTTP_NOT_EXTENDED = 510
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"""Builds an CGI Request object from the current CGI environment.
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This results in an object with all of the necessary methods and
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self.headers_written = False
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if ('SERVER_NAME' not in os.environ or
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'REQUEST_METHOD' not in os.environ or
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'SCRIPT_NAME' not in os.environ or
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'PATH_INFO' not in os.environ):
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raise Exception("No CGI environment found")
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# Determine if the browser used the public host name to make the
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# request (in which case we are in "public mode")
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if os.environ['SERVER_NAME'] == ivle.conf.public_host:
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self.publicmode = True
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self.publicmode = False
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# Inherit values for the input members
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self.method = os.environ['REQUEST_METHOD']
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self.uri = os.environ['SCRIPT_NAME'] + os.environ['PATH_INFO']
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# Split the given path into the app (top-level dir) and sub-path
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# (after first stripping away the root directory)
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path = ivle.util.unmake_path(self.uri)
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(_, self.path) = (ivle.util.split_path(path))
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(self.app, self.path) = (ivle.util.split_path(path))
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self.hostname = os.environ['SERVER_NAME']
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self.headers_in = _http_headers_in_from_cgi()
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self.headers_out = {}
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# Default values for the output members
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self.status = CGIRequest.HTTP_OK
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self.content_type = None # Use Apache's default
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self.title = None # Will be set by dispatch before passing to app
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self.write_html_head_foot = False
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self.got_common_vars = False
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def install_error_handler(self):
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'''Install our exception handler as the default.'''
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sys.excepthook = self.handle_unknown_exception
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def __writeheaders(self):
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"""Writes out the HTTP and HTML headers before any real data is
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self.headers_written = True
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if 'Content-Type' in self.headers_out:
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self.content_type = self.headers_out['Content-Type']
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if 'Location' in self.headers_out:
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self.location = self.headers_out['Location']
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# CGI allows for four response types: Document, Local Redirect, Client
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# Redirect, and Client Redirect w/ Document
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# XXX We do not allow Local Redirect
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if self.location != None:
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# This is a Client Redirect
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print "Location: %s" % self.location
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if self.content_type == None:
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# Else: This is a Client Redirect with Document
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print "Status: %d" % self.status
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print "Content-Type: %s" % self.content_type
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# This is a Document response
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print "Content-Type: %s" % self.content_type
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print "Status: %d" % self.status
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# Print the other headers
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for k,v in self.headers_out.items():
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if k != 'Content-Type' and k != 'Location':
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print "%s: %s" % (k, v)
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# XXX write_html_head_foot not supported
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#if self.write_html_head_foot:
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# # Write the HTML header, pass "self" (request object)
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# self.func_write_html_head(self)
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# Print a blank line to signal the start of output
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def ensure_headers_written(self):
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"""Writes out the HTTP and HTML headers if they haven't already been
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if not self.headers_written:
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self.__writeheaders()
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def write(self, string, flush=1):
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"""Writes string directly to the client, then flushes the buffer,
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unless flush is 0."""
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if not self.headers_written:
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self.__writeheaders()
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if isinstance(string, unicode):
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# Encode unicode strings as UTF-8
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# (Otherwise cannot handle being written to a bytestream)
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sys.stdout.write(string.encode('utf8'))
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# 8-bit clean strings just get written directly.
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# This includes binary strings.
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sys.stdout.write(string)
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"""Flushes the output buffer."""
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def sendfile(self, filename):
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"""Sends the named file directly to the client."""
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if not self.headers_written:
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self.__writeheaders()
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sys.stdout.write(buf)
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def read(self, len=None):
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"""Reads at most len bytes directly from the client. (See mod_python
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return sys.stdin.read()
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return sys.stdin.read(len)
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def throw_error(self, httpcode, message):
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"""Writes out an HTTP error of the specified code. Exits the process,
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so any code following this call will not be executed.
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(This is justified because of the nature of CGI, it is a single-script
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environment, there is no containing process which needs to catch an
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httpcode: An HTTP response status code. Pass a constant from the
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raise ivle.util.IVLEError(httpcode, message)
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def handle_unknown_exception(self, exc_type, exc_value, exc_tb):
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if exc_type is ivle.util.IVLEError:
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self.headers_out['X-IVLE-Error-Code'] = exc_value.httpcode
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self.headers_out['X-IVLE-Error-Type'] = exc_type.__name__
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self.headers_out['X-IVLE-Error-Message'] = exc_value.message
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except AttributeError:
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self.headers_out['X-IVLE-Error-Info'] = urllib.quote(''.join(
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traceback.format_exception(exc_type, exc_value, exc_tb)))
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self.ensure_headers_written()
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self.write('An internal IVLE error has occurred.')
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sys.exit(self.status)
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def throw_redirect(self, location):
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"""Writes out an HTTP redirect to the specified URL. Exits the
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process, so any code following this call will not be executed.
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httpcode: An HTTP response status code. Pass a constant from the
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self.status = CGIRequest.HTTP_MOVED_TEMPORARILY
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self.location = location
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self.ensure_headers_written()
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sys.exit(self.status)
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def get_session(self):
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"""Returns a mod_python Session object for this request.
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Note that this is dependent on mod_python and may need to change
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interface if porting away from mod_python."""
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# Cache the session object
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if not hasattr(self, 'session'):
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#self.session = Session.FileSession(self.apache_req)
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# FIXME: How to get session?
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def get_fieldstorage(self):
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"""Returns a mod_python FieldStorage object for this request.
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Note that this is dependent on mod_python and may need to change
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interface if porting away from mod_python."""
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# Cache the fieldstorage object
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if not hasattr(self, 'fields'):
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self.fields = cgi.FieldStorage()
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def get_cgi_environ(self):
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"""Returns the CGI environment emulation for this request. (Calls
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add_common_vars). The environment is returned as a mapping
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compatible with os.environ."""
added
removed
ivle/cgirequest.py
