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.
38
from ivle.webapp.base.plugins import CookiePlugin
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
List of strings. Write a list of URLs to CSS files here, and they
82
will be incorporated as <link rel="stylesheet" type="text/css">
83
elements in the head, if write_html_head_foot is True.
84
URLs should be relative to the IVLE root; they will be fixed up
87
List of strings. Write a list of URLs to JS files here, and they
88
will be incorporated as <script type="text/javascript"> elements
89
in the head, if write_html_head_foot is True.
90
URLs should be relative to the IVLE root; they will be fixed up
93
List of strings. Write a list of JS function names, and they
94
will be added as window.addListener('load', ..., false); calls
95
in the head, if write_html_head_foot is True.
96
This is the propper way to specify functions that need to run at
100
# Special code for an OK response.
101
# Do not use HTTP_OK; for some reason Apache produces an "OK" error
102
# message if you do that.
108
HTTP_SWITCHING_PROTOCOLS = 101
109
HTTP_PROCESSING = 102
113
HTTP_NON_AUTHORITATIVE = 203
114
HTTP_NO_CONTENT = 204
115
HTTP_RESET_CONTENT = 205
116
HTTP_PARTIAL_CONTENT = 206
117
HTTP_MULTI_STATUS = 207
118
HTTP_MULTIPLE_CHOICES = 300
119
HTTP_MOVED_PERMANENTLY = 301
120
HTTP_MOVED_TEMPORARILY = 302
122
HTTP_NOT_MODIFIED = 304
124
HTTP_TEMPORARY_REDIRECT = 307
125
HTTP_BAD_REQUEST = 400
126
HTTP_UNAUTHORIZED = 401
127
HTTP_PAYMENT_REQUIRED = 402
130
HTTP_METHOD_NOT_ALLOWED = 405
131
HTTP_NOT_ACCEPTABLE = 406
132
HTTP_PROXY_AUTHENTICATION_REQUIRED= 407
133
HTTP_REQUEST_TIME_OUT = 408
136
HTTP_LENGTH_REQUIRED = 411
137
HTTP_PRECONDITION_FAILED = 412
138
HTTP_REQUEST_ENTITY_TOO_LARGE = 413
139
HTTP_REQUEST_URI_TOO_LARGE = 414
140
HTTP_UNSUPPORTED_MEDIA_TYPE = 415
141
HTTP_RANGE_NOT_SATISFIABLE = 416
142
HTTP_EXPECTATION_FAILED = 417
143
HTTP_UNPROCESSABLE_ENTITY = 422
145
HTTP_FAILED_DEPENDENCY = 424
146
HTTP_INTERNAL_SERVER_ERROR = 500
147
HTTP_NOT_IMPLEMENTED = 501
148
HTTP_BAD_GATEWAY = 502
149
HTTP_SERVICE_UNAVAILABLE = 503
150
HTTP_GATEWAY_TIME_OUT = 504
151
HTTP_VERSION_NOT_SUPPORTED = 505
152
HTTP_VARIANT_ALSO_VARIES = 506
153
HTTP_INSUFFICIENT_STORAGE = 507
154
HTTP_NOT_EXTENDED = 510
156
def __init__(self, req, config):
157
"""Create an IVLE request from a mod_python one.
159
@param req: A mod_python request.
160
@param config: An IVLE configuration.
163
# Methods are mostly wrappers around the Apache request object
164
self.apache_req = req
166
self.headers_written = False
168
# Determine if the browser used the public host name to make the
169
# request (in which case we are in "public mode")
170
if req.hostname == config['urls']['public_host']:
171
self.publicmode = True
173
self.publicmode = False
175
# Inherit values for the input members
176
self.method = req.method
178
# Split the given path into the app (top-level dir) and sub-path
179
# (after first stripping away the root directory)
180
path = ivle.util.unmake_path(req.uri)
181
(self.app, self.path) = (ivle.util.split_path(path))
183
self.hostname = req.hostname
184
self.headers_in = req.headers_in
185
self.headers_out = req.headers_out
187
# Open a database connection and transaction, keep it around for users
188
# of the Request object to use
189
self.store = ivle.database.get_store(config)
191
# Default values for the output members
192
self.status = Request.HTTP_OK
193
self.content_type = None # Use Apache's default
197
self.scripts_init = []
198
# In some cases we don't want the template JS (such as the username
199
# and public FQDN) in the output HTML. In that case, set this to 0.
200
self.write_javascript_settings = True
201
self.got_common_vars = False
207
def __writeheaders(self):
208
"""Writes out the HTTP and HTML headers before any real data is
210
self.headers_written = True
212
# Prepare the HTTP and HTML headers before the first write is made
213
if self.content_type != None:
214
self.apache_req.content_type = self.content_type
215
self.apache_req.status = self.status
216
if self.location != None:
217
self.apache_req.headers_out['Location'] = self.location
219
def ensure_headers_written(self):
220
"""Writes out the HTTP and HTML headers if they haven't already been
222
if not self.headers_written:
223
self.__writeheaders()
225
def write(self, string, flush=1):
226
"""Writes string directly to the client, then flushes the buffer,
227
unless flush is 0."""
229
if not self.headers_written:
230
self.__writeheaders()
231
if isinstance(string, unicode):
232
# Encode unicode strings as UTF-8
233
# (Otherwise cannot handle being written to a bytestream)
234
self.apache_req.write(string.encode('utf8'), flush)
236
# 8-bit clean strings just get written directly.
237
# This includes binary strings.
238
self.apache_req.write(string, flush)
241
"""Log out the current user by destroying the session state.
242
Then redirect to the top-level IVLE page."""
243
if hasattr(self, 'session'):
244
self.session.invalidate()
245
self.session.delete()
246
# Invalidates all IVLE cookies
247
all_cookies = mod_python.Cookie.get_cookies(self)
249
# Create cookies for plugins that might request them.
250
for plugin in self.config.plugin_index[CookiePlugin]:
251
for cookie in plugin.cookies:
252
self.add_cookie(mod_python.Cookie.Cookie(cookie, '',
253
expires=1, path='/'))
254
self.throw_redirect(ivle.util.make_path(''))
258
"""Flushes the output buffer."""
259
self.apache_req.flush()
261
def sendfile(self, filename):
262
"""Sends the named file directly to the client."""
263
if not self.headers_written:
264
self.__writeheaders()
265
self.apache_req.sendfile(filename)
267
def read(self, len=None):
268
"""Reads at most len bytes directly from the client. (See mod_python
271
return self.apache_req.read()
273
return self.apache_req.read(len)
275
def throw_redirect(self, location):
276
"""Writes out an HTTP redirect to the specified URL. Raises an
277
exception which is caught by the dispatch or web server, so any
278
code following this call will not be executed.
280
httpcode: An HTTP response status code. Pass a constant from the
283
# Note: location may be a unicode, but it MUST only have ASCII
284
# characters (non-ascii characters should be URL-encoded).
285
mod_python.util.redirect(self.apache_req, location.encode("ascii"))
287
def add_cookie(self, cookie, value=None, **attributes):
288
"""Inserts a cookie into this request object's headers."""
290
mod_python.Cookie.add_cookie(self.apache_req, cookie)
292
mod_python.Cookie.add_cookie(self.apache_req, cookie, value, **attributes)
294
def get_session(self):
295
"""Returns a mod_python Session object for this request.
296
Note that this is dependent on mod_python and may need to change
297
interface if porting away from mod_python.
299
IMPORTANT: Call unlock() on the session as soon as you are done with
300
it! If you don't, all other requests will block!
302
# Cache the session object and set the timeout to 24 hours.
303
if not hasattr(self, 'session'):
304
self.session = mod_python.Session.FileSession(self.apache_req,
305
timeout = 60 * 60 * 24)
308
def get_fieldstorage(self):
309
"""Returns a mod_python FieldStorage object for this request.
310
Note that this is dependent on mod_python and may need to change
311
interface if porting away from mod_python."""
312
# Cache the fieldstorage object
313
if not hasattr(self, 'fields'):
314
self.fields = mod_python.util.FieldStorage(self.apache_req)
317
def get_cgi_environ(self):
318
"""Returns the CGI environment emulation for this request. (Calls
319
add_common_vars). The environment is returned as a mapping
320
compatible with os.environ."""
321
if not self.got_common_vars:
322
self.apache_req.add_common_vars()
323
self.got_common_vars = True
324
return self.apache_req.subprocess_env
327
def get_http_codename(code):
328
"""Given a HTTP error code int, returns a (name, description)
329
pair, suitable for displaying to the user.
330
May return (None,None) if code is unknown.
331
Only lists common 4xx and 5xx codes (since this is just used
332
to display throw_error error messages).
335
return http_codenames[code]
339
# Human strings for HTTP response codes
341
Request.HTTP_BAD_REQUEST:
343
"Your browser sent a request IVLE did not understand."),
344
Request.HTTP_UNAUTHORIZED:
346
"You are not allowed to view this part of IVLE."),
347
Request.HTTP_FORBIDDEN:
349
"You are not allowed to view this part of IVLE."),
350
Request.HTTP_NOT_FOUND:
352
"The application or file you requested does not exist."),
353
Request.HTTP_METHOD_NOT_ALLOWED:
354
("Method Not Allowed",
355
"Your browser is interacting with IVLE in the wrong way."
356
"This is probably a bug in IVLE. "
357
"Please report it to the administrators."),
358
Request.HTTP_INTERNAL_SERVER_ERROR:
359
("Internal Server Error",
360
"An unknown error occured in IVLE."),
361
Request.HTTP_NOT_IMPLEMENTED:
363
"The application or file you requested has not been implemented "
365
Request.HTTP_SERVICE_UNAVAILABLE:
366
("Service Unavailable",
367
"IVLE is currently experiencing technical difficulties. "
368
"Please try again later."),