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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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# Module: dispatch.request
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# Builds an IVLE request object from a mod_python request object.
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# See design notes/apps/dispatch.txt for a full specification of this request
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from mod_python import (util, Session, Cookie)
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import plugins.console
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"""An IVLE request object. This is presented to the IVLE apps as a way of
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interacting with the web server and the dispatcher.
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Request object attributes:
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String. The request method (eg. 'GET', 'POST', etc)
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String. The path portion of the URI.
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String. Name of the application specified in the URL, or None.
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String. The path specified in the URL *not including* the
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application or the IVLE location prefix. eg. a URL of
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"/ivle/files/joe/myfiles" has a path of "joe/myfiles".
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User object. Details of the user who is currently logged in, or
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String. Hostname the server is running on.
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Table object representing headers sent by the client.
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headers_out (read, can be written to)
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Table object representing headers to be sent to the client.
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Bool. True if the request came for the "public host" as
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configured in conf.py. Note that public mode requests do not
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have an app (app is set to None).
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Int. Response status number. Use one of the status codes defined
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String. The Content-Type (mime type) header value.
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String. Response "Location" header value. Used with HTTP redirect
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String. HTML page title. Used if write_html_head_foot is True, in
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the HTML title element text.
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List of strings. Write a list of URLs to CSS files here, and they
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will be incorporated as <link rel="stylesheet" type="text/css">
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elements in the head, if write_html_head_foot is True.
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URLs should be relative to the IVLE root; they will be fixed up
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List of strings. Write a list of URLs to JS files here, and they
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will be incorporated as <script type="text/javascript"> elements
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in the head, if write_html_head_foot is True.
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URLs should be relative to the IVLE root; they will be fixed up
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List of strings. Write a list of JS function names, and they
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will be added as window.addListener('load', ..., false); calls
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in the head, if write_html_head_foot is True.
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This is the propper way to specify functions that need to run at
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write_html_head_foot (write)
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Boolean. If True, dispatch assumes that this is an XHTML page, and
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will immediately write a full HTML head, open the body element,
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and write heading contents to the page, before any bytes are
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written. It will then write footer contents and close the body and
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html elements at the end of execution.
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This value should be set to true by all applications for all HTML
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output (unless there is a good reason, eg. exec). The
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applications should therefore output HTML content assuming that
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it will be written inside the body tag. Do not write opening or
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closing <html> or <body> tags.
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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_PROCESSING = 102
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HTTP_NON_AUTHORITATIVE = 203
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HTTP_NO_CONTENT = 204
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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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def __init__(self, req, write_html_head):
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"""Builds an IVLE request object from a mod_python request object.
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This results in an object with all of the necessary methods and
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req: A mod_python request object.
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write_html_head: Function which is called when writing the automatic
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HTML header. Accepts a single argument, the IVLE request object.
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# Methods are mostly wrappers around the Apache request object
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self.apache_req = req
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self.func_write_html_head = write_html_head
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self.headers_written = False
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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 req.hostname == 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 = req.method
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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 = common.util.unmake_path(req.uri)
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(_, self.path) = (common.util.split_path(path))
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(self.app, self.path) = (common.util.split_path(path))
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self.hostname = req.hostname
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self.headers_in = req.headers_in
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self.headers_out = req.headers_out
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# Default values for the output members
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self.status = Request.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.scripts_init = []
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self.write_html_head_foot = False
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self.got_common_vars = False
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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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# app is the App object for the chosen app
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app = conf.apps.app_url[self.app]
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# Write any final modifications to header content
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if app and app.useconsole and self.user:
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plugins.console.insert_scripts_styles(self.scripts, self.styles, \
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# Prepare the HTTP and HTML headers before the first write is made
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if self.content_type != None:
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self.apache_req.content_type = self.content_type
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self.apache_req.status = self.status
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if self.location != None:
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self.apache_req.headers_out['Location'] = self.location
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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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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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self.apache_req.write(string.encode('utf8'), flush)
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# 8-bit clean strings just get written directly.
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# This includes binary strings.
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self.apache_req.write(string, flush)
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"""Flushes the output buffer."""
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self.apache_req.flush()
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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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self.apache_req.sendfile(filename)
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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 self.apache_req.read()
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return self.apache_req.read(len)
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def throw_error(self, httpcode, message=None):
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"""Writes out an HTTP error of the specified code. Raises an exception
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which is caught by the dispatch or web server, so any code following
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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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raise common.util.IVLEError(httpcode, message)
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def throw_redirect(self, location):
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"""Writes out an HTTP redirect to the specified URL. Raises an
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exception which is caught by the dispatch or web server, so any
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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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mod_python.util.redirect(self.apache_req, location)
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def add_cookie(self, cookie, value=None, **attributes):
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"""Inserts a cookie into this request object's headers."""
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Cookie.add_cookie(self.apache_req, cookie)
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Cookie.add_cookie(self.apache_req, cookie, value, **attributes)
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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 and set the timeout to 24 hours.
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if not hasattr(self, 'session'):
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self.session = Session.FileSession(self.apache_req,
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timeout = 60 * 60 * 24)
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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 = util.FieldStorage(self.apache_req)
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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."""
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if not self.got_common_vars:
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self.apache_req.add_common_vars()
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self.got_common_vars = True
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return self.apache_req.subprocess_env
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def get_http_codename(code):
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"""Given a HTTP error code int, returns a (name, description)
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pair, suitable for displaying to the user.
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May return (None,None) if code is unknown.
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Only lists common 4xx and 5xx codes (since this is just used
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to display throw_error error messages).
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return http_codenames[code]
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# Human strings for HTTP response codes
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Request.HTTP_BAD_REQUEST:
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"Your browser sent a request IVLE did not understand."),
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Request.HTTP_UNAUTHORIZED:
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"You are not allowed to view this part of IVLE."),
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Request.HTTP_FORBIDDEN:
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"You are not allowed to view this part of IVLE."),
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Request.HTTP_NOT_FOUND:
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"The application or file you requested does not exist."),
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Request.HTTP_METHOD_NOT_ALLOWED:
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("Method Not Allowed",
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"Your browser is interacting with IVLE in the wrong way."
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"This is probably a bug in IVLE. "
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"Please report it to the administrators."),
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Request.HTTP_INTERNAL_SERVER_ERROR:
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("Internal Server Error",
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"An unknown error occured in IVLE."),
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Request.HTTP_NOT_IMPLEMENTED:
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"The application or file you requested has not been implemented "
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Request.HTTP_SERVICE_UNAVAILABLE:
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("Service Unavailable",
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"IVLE is currently experiencing technical difficulties. "
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"Please try again later."),
added
removed
www/dispatch/request.py
