1
# IVLE - Informatics Virtual Learning Environment
2
# Copyright (C) 2007-2009 The University of Melbourne
4
# This program is free software; you can redistribute it and/or modify
5
# it under the terms of the GNU General Public License as published by
6
# the Free Software Foundation; either version 2 of the License, or
7
# (at your option) any later version.
9
# This program is distributed in the hope that it will be useful,
10
# but WITHOUT ANY WARRANTY; without even the implied warranty of
11
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12
# GNU General Public License for more details.
14
# You should have received a copy of the GNU General Public License
15
# along with this program; if not, write to the Free Software
16
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23
Builds an IVLE request object from a mod_python request object.
24
See design notes/apps/dispatch.txt for a full specification of this request
29
import mod_python.Session
30
import mod_python.Cookie
31
import mod_python.util
33
# This needs to be importable from outside Apache.
41
"""An IVLE request object. This is presented to the IVLE apps as a way of
42
interacting with the web server and the dispatcher.
44
Request object attributes:
46
String. The request method (eg. 'GET', 'POST', etc)
48
String. The path portion of the URI.
50
String. Name of the application specified in the URL, or None.
52
String. The path specified in the URL *not including* the
53
application or the IVLE location prefix. eg. a URL of
54
"/ivle/files/joe/myfiles" has a path of "joe/myfiles".
56
User object. Details of the user who is currently logged in, or
59
storm.store.Store instance. Holds a database transaction open,
60
which is available for the entire lifetime of the request.
62
String. Hostname the server is running on.
64
Table object representing headers sent by the client.
65
headers_out (read, can be written to)
66
Table object representing headers to be sent to the client.
68
Bool. True if the request came for the "public host" as
69
configured in conf.py. Note that public mode requests do not
70
have an app (app is set to None).
73
Int. Response status number. Use one of the status codes defined
76
String. The Content-Type (mime type) header value.
78
String. Response "Location" header value. Used with HTTP redirect
81
String. HTML page title. Used if write_html_head_foot is True, in
82
the HTML title element text.
84
List of strings. Write a list of URLs to CSS files here, and they
85
will be incorporated as <link rel="stylesheet" type="text/css">
86
elements in the head, if write_html_head_foot is True.
87
URLs should be relative to the IVLE root; they will be fixed up
90
List of strings. Write a list of URLs to JS files here, and they
91
will be incorporated as <script type="text/javascript"> elements
92
in the head, if write_html_head_foot is True.
93
URLs should be relative to the IVLE root; they will be fixed up
96
List of strings. Write a list of JS function names, and they
97
will be added as window.addListener('load', ..., false); calls
98
in the head, if write_html_head_foot is True.
99
This is the propper way to specify functions that need to run at
101
write_html_head_foot (write)
102
Boolean. If True, dispatch assumes that this is an XHTML page, and
103
will immediately write a full HTML head, open the body element,
104
and write heading contents to the page, before any bytes are
105
written. It will then write footer contents and close the body and
106
html elements at the end of execution.
108
This value should be set to true by all applications for all HTML
109
output (unless there is a good reason, eg. exec). The
110
applications should therefore output HTML content assuming that
111
it will be written inside the body tag. Do not write opening or
112
closing <html> or <body> tags.
115
# Special code for an OK response.
116
# Do not use HTTP_OK; for some reason Apache produces an "OK" error
117
# message if you do that.
123
HTTP_SWITCHING_PROTOCOLS = 101
124
HTTP_PROCESSING = 102
128
HTTP_NON_AUTHORITATIVE = 203
129
HTTP_NO_CONTENT = 204
130
HTTP_RESET_CONTENT = 205
131
HTTP_PARTIAL_CONTENT = 206
132
HTTP_MULTI_STATUS = 207
133
HTTP_MULTIPLE_CHOICES = 300
134
HTTP_MOVED_PERMANENTLY = 301
135
HTTP_MOVED_TEMPORARILY = 302
137
HTTP_NOT_MODIFIED = 304
139
HTTP_TEMPORARY_REDIRECT = 307
140
HTTP_BAD_REQUEST = 400
141
HTTP_UNAUTHORIZED = 401
142
HTTP_PAYMENT_REQUIRED = 402
145
HTTP_METHOD_NOT_ALLOWED = 405
146
HTTP_NOT_ACCEPTABLE = 406
147
HTTP_PROXY_AUTHENTICATION_REQUIRED= 407
148
HTTP_REQUEST_TIME_OUT = 408
151
HTTP_LENGTH_REQUIRED = 411
152
HTTP_PRECONDITION_FAILED = 412
153
HTTP_REQUEST_ENTITY_TOO_LARGE = 413
154
HTTP_REQUEST_URI_TOO_LARGE = 414
155
HTTP_UNSUPPORTED_MEDIA_TYPE = 415
156
HTTP_RANGE_NOT_SATISFIABLE = 416
157
HTTP_EXPECTATION_FAILED = 417
158
HTTP_UNPROCESSABLE_ENTITY = 422
160
HTTP_FAILED_DEPENDENCY = 424
161
HTTP_INTERNAL_SERVER_ERROR = 500
162
HTTP_NOT_IMPLEMENTED = 501
163
HTTP_BAD_GATEWAY = 502
164
HTTP_SERVICE_UNAVAILABLE = 503
165
HTTP_GATEWAY_TIME_OUT = 504
166
HTTP_VERSION_NOT_SUPPORTED = 505
167
HTTP_VARIANT_ALSO_VARIES = 506
168
HTTP_INSUFFICIENT_STORAGE = 507
169
HTTP_NOT_EXTENDED = 510
171
def __init__(self, req, write_html_head):
172
"""Builds an IVLE request object from a mod_python request object.
173
This results in an object with all of the necessary methods and
176
req: A mod_python request object.
177
write_html_head: Function which is called when writing the automatic
178
HTML header. Accepts a single argument, the IVLE request object.
181
# Methods are mostly wrappers around the Apache request object
182
self.apache_req = req
183
self.func_write_html_head = write_html_head
184
self.headers_written = False
186
# Determine if the browser used the public host name to make the
187
# request (in which case we are in "public mode")
188
if req.hostname == ivle.conf.public_host:
189
self.publicmode = True
191
self.publicmode = False
193
# Inherit values for the input members
194
self.method = req.method
196
# Split the given path into the app (top-level dir) and sub-path
197
# (after first stripping away the root directory)
198
path = ivle.util.unmake_path(req.uri)
199
(self.app, self.path) = (ivle.util.split_path(path))
201
self.hostname = req.hostname
202
self.headers_in = req.headers_in
203
self.headers_out = req.headers_out
205
# Open a database connection and transaction, keep it around for users
206
# of the Request object to use
207
self.store = ivle.database.get_store()
209
# Default values for the output members
210
self.status = Request.HTTP_OK
211
self.content_type = None # Use Apache's default
213
self.title = None # Will be set by dispatch before passing to app
216
self.scripts_init = []
217
self.write_html_head_foot = False
218
# In some cases we don't want the template JS (such as the username
219
# and public FQDN) in the output HTML. In that case, set this to 0.
220
self.write_javascript_settings = True
221
self.got_common_vars = False
227
def __writeheaders(self):
228
"""Writes out the HTTP and HTML headers before any real data is
230
self.headers_written = True
232
# app is the App object for the chosen app
234
app = ivle.conf.apps.app_url[self.app]
238
# Prepare the HTTP and HTML headers before the first write is made
239
if self.content_type != None:
240
self.apache_req.content_type = self.content_type
241
self.apache_req.status = self.status
242
if self.location != None:
243
self.apache_req.headers_out['Location'] = self.location
244
if self.write_html_head_foot:
245
# Write the HTML header, pass "self" (request object)
246
self.func_write_html_head(self)
248
def ensure_headers_written(self):
249
"""Writes out the HTTP and HTML headers if they haven't already been
251
if not self.headers_written:
252
self.__writeheaders()
254
def write(self, string, flush=1):
255
"""Writes string directly to the client, then flushes the buffer,
256
unless flush is 0."""
258
if not self.headers_written:
259
self.__writeheaders()
260
if isinstance(string, unicode):
261
# Encode unicode strings as UTF-8
262
# (Otherwise cannot handle being written to a bytestream)
263
self.apache_req.write(string.encode('utf8'), flush)
265
# 8-bit clean strings just get written directly.
266
# This includes binary strings.
267
self.apache_req.write(string, flush)
270
"""Log out the current user by destroying the session state.
271
Then redirect to the top-level IVLE page."""
272
# List of cookies that IVLE uses (to be removed at logout)
273
ivle_cookies = ["ivleforumcookie", "clipboard"]
275
if hasattr(self, 'session'):
276
self.session.invalidate()
277
self.session.delete()
278
# Invalidates all IVLE cookies
279
all_cookies = mod_python.Cookie.get_cookies(self)
280
for cookie in all_cookies:
281
if cookie in ivle_cookies:
282
self.add_cookie(mod_python.Cookie.Cookie(cookie,'',expires=1,path='/'))
283
self.throw_redirect(ivle.util.make_path(''))
287
"""Flushes the output buffer."""
288
self.apache_req.flush()
290
def sendfile(self, filename):
291
"""Sends the named file directly to the client."""
292
if not self.headers_written:
293
self.__writeheaders()
294
self.apache_req.sendfile(filename)
296
def read(self, len=None):
297
"""Reads at most len bytes directly from the client. (See mod_python
300
return self.apache_req.read()
302
return self.apache_req.read(len)
304
def throw_error(self, httpcode, message=None):
305
"""Writes out an HTTP error of the specified code. Raises an exception
306
which is caught by the dispatch or web server, so any code following
307
this call will not be executed.
309
httpcode: An HTTP response status code. Pass a constant from the
312
raise ivle.util.IVLEError(httpcode, message)
314
def throw_redirect(self, location):
315
"""Writes out an HTTP redirect to the specified URL. Raises an
316
exception which is caught by the dispatch or web server, so any
317
code following this call will not be executed.
319
httpcode: An HTTP response status code. Pass a constant from the
322
# Note: location may be a unicode, but it MUST only have ASCII
323
# characters (non-ascii characters should be URL-encoded).
324
mod_python.util.redirect(self.apache_req, location.encode("ascii"))
326
def add_cookie(self, cookie, value=None, **attributes):
327
"""Inserts a cookie into this request object's headers."""
329
mod_python.Cookie.add_cookie(self.apache_req, cookie)
331
mod_python.Cookie.add_cookie(self.apache_req, cookie, value, **attributes)
333
def get_session(self):
334
"""Returns a mod_python Session object for this request.
335
Note that this is dependent on mod_python and may need to change
336
interface if porting away from mod_python."""
337
# Cache the session object and set the timeout to 24 hours.
338
if not hasattr(self, 'session'):
339
self.session = mod_python.Session.FileSession(self.apache_req,
340
timeout = 60 * 60 * 24)
343
def get_fieldstorage(self):
344
"""Returns a mod_python FieldStorage object for this request.
345
Note that this is dependent on mod_python and may need to change
346
interface if porting away from mod_python."""
347
# Cache the fieldstorage object
348
if not hasattr(self, 'fields'):
349
self.fields = mod_python.util.FieldStorage(self.apache_req)
352
def get_cgi_environ(self):
353
"""Returns the CGI environment emulation for this request. (Calls
354
add_common_vars). The environment is returned as a mapping
355
compatible with os.environ."""
356
if not self.got_common_vars:
357
self.apache_req.add_common_vars()
358
self.got_common_vars = True
359
return self.apache_req.subprocess_env
362
def get_http_codename(code):
363
"""Given a HTTP error code int, returns a (name, description)
364
pair, suitable for displaying to the user.
365
May return (None,None) if code is unknown.
366
Only lists common 4xx and 5xx codes (since this is just used
367
to display throw_error error messages).
370
return http_codenames[code]
374
# Human strings for HTTP response codes
376
Request.HTTP_BAD_REQUEST:
378
"Your browser sent a request IVLE did not understand."),
379
Request.HTTP_UNAUTHORIZED:
381
"You are not allowed to view this part of IVLE."),
382
Request.HTTP_FORBIDDEN:
384
"You are not allowed to view this part of IVLE."),
385
Request.HTTP_NOT_FOUND:
387
"The application or file you requested does not exist."),
388
Request.HTTP_METHOD_NOT_ALLOWED:
389
("Method Not Allowed",
390
"Your browser is interacting with IVLE in the wrong way."
391
"This is probably a bug in IVLE. "
392
"Please report it to the administrators."),
393
Request.HTTP_INTERNAL_SERVER_ERROR:
394
("Internal Server Error",
395
"An unknown error occured in IVLE."),
396
Request.HTTP_NOT_IMPLEMENTED:
398
"The application or file you requested has not been implemented "
400
Request.HTTP_SERVICE_UNAVAILABLE:
401
("Service Unavailable",
402
"IVLE is currently experiencing technical difficulties. "
403
"Please try again later."),
added
removed
ivle/dispatch/request.py
