1 Introduction
2 ------------
3
4 WebStack is a package which provides a common API for Python Web
5 applications, regardless of the underlying server or framework environment.
6 It should be possible with WebStack to design and implement an application,
7 to choose a deployment environment, and then to be able to deploy the
8 application in a different environment later on without having to go back
9 and rewrite substantial parts of the application.
10
11 Quick Start
12 -----------
13
14 Try running the demo:
15
16 python tools/demo.py
17
18 An introductory guide to creating applications can be found in the docs
19 directory - see docs/index.html for the start page.
20
21 Contact, Copyright and Licence Information
22 ------------------------------------------
23
24 The current Web page for WebStack at the time of release is:
25
26 http://www.boddie.org.uk/python/WebStack.html
27
28 Copyright and licence information can be found in the docs directory - see
29 docs/COPYING.txt, docs/LICENCE.txt and docs/LICENCE-PyServlet.txt for more
30 information.
31
32 Framework Support
33 -----------------
34
35 See the docs/supported-frameworks.html document for more information.
36
37 New in WebStack 1.2.6 (Changes since WebStack 1.2.5)
38 ----------------------------------------------------
39
40 * Improved support for Jython on Ubuntu Feisty (7.04), adding python.path
41 and python.cachedir settings which respectively avoid issues with missing
42 libraries (due to the separation of libraries in the Ubuntu package) and
43 with failed imports (due to a read-only class cache directory).
44 * Added more Jython-related documentation as suggested by Kevin Glynn.
45 * Added missing request headers for CGI/WSGI environment variables.
46 * Fixed Webware support to work with Webware 0.9.4.
47 * Fixed/improved Zope path value retrieval.
48
49 New in WebStack 1.2.5 (Changes since WebStack 1.2.4)
50 ----------------------------------------------------
51
52 * Fixed mod_python status codes using a solution proposed by John Krukoff.
53 * Fixed a Twisted deprecation warning when accessing port numbers, thanks to
54 John Krukoff.
55 * Added Ubuntu Feisty (7.04) package support.
56 * Tidied up the documentation HTML.
57
58 New in WebStack 1.2.4 (Changes since WebStack 1.2.3)
59 ----------------------------------------------------
60
61 * Made a SessionDirectoryRepository which uses directories for data produced
62 by the shelve module, rather than attempting to manipulate files produced
63 by the shelve module, since the details of such files may differ between
64 environments: a situation noticed by John Krukoff in an environment
65 without the bsddb module installed.
66
67 New in WebStack 1.2.3 (Changes since WebStack 1.2.2)
68 ----------------------------------------------------
69
70 * Fixed inadvertent OpenSSL dependency, noticed by John Krukoff.
71
72 New in WebStack 1.2.2 (Changes since WebStack 1.2.1)
73 ----------------------------------------------------
74
75 * Added an EncodingSelector class for the setting of default encodings on
76 transactions.
77 * Added some documentation about path processing strategies.
78 * Added a secure variant of the BaseHTTPServer provided in the adapter for
79 BaseHTTPRequestHandler.
80
81 New in WebStack 1.2.1 (Changes since WebStack 1.2)
82 --------------------------------------------------
83
84 * Fixed mod_python get_content_type method.
85 * Fixed LoginResource form field processing; changed the field type to
86 password.
87 * Exposed LoginResource and LoginRedirectResource page contents as
88 attributes.
89 * Added documentation about extending LoginRedirectResource and using
90 PathSelector to remember an application's root path.
91 * Changed handle_errors to 1 throughout the examples.
92
93 New in WebStack 1.2 (Changes since WebStack 1.1.2)
94 --------------------------------------------------
95
96 * Added support for Django.
97 * Fixed documentation about the representation of file upload fields.
98 * Changed mod_python, Java Servlet and Webware (> 0.8.1) deployment to use a
99 deploy function instead of more complicated configuration mechanisms.
100 * Improved mod_python deployment documentation and tools so that cleaner
101 application paths/URLs can now be used.
102 * Moved user and path_info default definitions into WebStack.Generic as
103 class attributes.
104 * Fixed encoding usage issues with path fields when using get_fields in a
105 Zope environment.
106 * Added a FileResource class to WebStack.Resources.Static.
107 * Made DirectoryRepository convert filenames to Unicode in all cases.
108 * Renamed the Apache and Java Servlet tools, making them scripts which are
109 installed by setup.py.
110 * Fixed CGI content charsets and languages support.
111 * Fixed CGI cookie output.
112 * Added URL overriding in the LoginRedirectResource.
113 * Exposed a get_target function from WebStack.Resources.Login in order to
114 better support alternative login resources.
115 * Added improved error reporting for BaseHTTPRequestHandler, CGI, Django and
116 WSGI.
117 * Added a traverse_path method to the Transaction class.
118 * Made a path_encoding alias for urlencoding in the initialisation of
119 WebStack.Resources.ResourceMap objects.
120 * Added a Selectors module to WebStack.Resources in order to support common
121 resource selection patterns.
122
123 New in WebStack 1.1.2 (Changes since WebStack 1.1.1)
124 ----------------------------------------------------
125
126 * Fixed missing import in WebStack.Repositories.Directory.
127
128 New in WebStack 1.1.1 (Changes since WebStack 1.1)
129 --------------------------------------------------
130
131 * Fixed update_path to handle the root path properly.
132
133 New in WebStack 1.1 (Changes since WebStack 1.0)
134 ------------------------------------------------
135
136 * Added a Repositories package to provide session-like support for
137 different kinds of storage.
138 * Added an explicit filesystem encoding to the Calendar example and adopted
139 the DirectoryRepository from the Repositories package.
140 * Added get_path_without_info, update_path and redirect methods to the
141 Transaction class.
142 * Added get_attributes (attribute support) to the Transaction class.
143 * Added a values method to Helpers.Session.Wrapper.
144 * Fixed get_processed_virtual_path_info (to match from right to left).
145 * Improved/fixed exception handling in the adapters so that transactions are
146 committed as the final act of an adapter experiencing an unhandled
147 exception. This should result in session stores being closed properly.
148 * Changed the Helpers.Session.SessionStore to use DirectoryRepository.
149 * Made the "not found" behaviour of DirectoryResource more configurable.
150 * Added documentation for MapResource and DirectoryResource.
151 * Fixed the distribution names in the Ubuntu changelog.
152
153 New in WebStack 1.0 (Changes since WebStack 0.10)
154 -------------------------------------------------
155
156 * Changed the behaviour of get_path, get_path_without_query, get_path_info,
157 get_virtual_path_info, get_processed_virtual_path_info and
158 get_fields_from_path to return Unicode data decoded using the optional
159 encoding parameter or a common default encoding.
160 * Fixed file upload values so that FileContent objects are returned for such
161 fields in get_fields_from_body and get_fields.
162 (Warning! Except for Twisted!)
163 * Fixed the JavaServlet support so that streams and file content are
164 obtained as "almost" plain strings.
165 * Updated/fixed LoginResource and LoginRedirectResource to use the updated
166 path API and to handle special characters properly.
167 * Added convenience methods to Transaction for the decoding and encoding of
168 path values (to and from Unicode objects) - see the decode_path and
169 encode_path methods.
170 * Added the notion of processed virtual path info - the part of the original
171 path info not represented in the current virtual path info.
172 * Added "pass through" behaviour to ResourceMap.MapResource (prompted by a
173 patch from Scott Robinson).
174 * Fixed ResourceMap.MapResource to handle non-existent resources properly
175 (where the virtual path info is only one component in length).
176 * Added Debian package support.
177 * Added automatic session directory creation for the WebStack sessions
178 implementation.
179 * Added support for the repeated retrieval of sessions from the same
180 WebStack session store, avoiding deadlocks.
181 * Fixed the calendar example, making it perform a proper function.
182 * Made the BaseHTTPRequestHandler and Twisted SimpleWithLogin applications
183 include the Login application, since Konqueror (at least) does not share
184 cookies across different port numbers on the same host.
185 * Added the SimpleWithLogin and Login applications to the demonstration.
186 * Improved the documentation, adding information on request headers, and
187 describing file upload and session support limitations.
188 * Improved the AOLserver-related notes for CGI and Webware, adding a patch
189 for Webware in order to work around AOLserver issues.
190
191 New in WebStack 0.10 (Changes since WebStack 0.9)
192 -------------------------------------------------
193
194 * Changes to make the tools/demo.py script work on Windows (and other)
195 platforms (suggested by Jim Madsen).
196 * Fixed end of header newlines for CGI (suggested by Matt Harrison).
197 * Minor documentation fixes and improvements, adding information on
198 AOLserver in the CGI and Webware notes.
199 * Changed the mod_python server name method to use the server object rather
200 than the connection object.
201 * Added a parameter to the ResourceMap.MapResource class to permit automatic
202 redirects into resource hierarchies when no trailing "/" was given in the
203 URL; changed the updated virtual path info so that empty values may be set
204 (the guarantee that "/" will always appear no longer applies).
205 * Fixed virtual path info retrieval when the value is an empty string.
206
207 New in WebStack 0.9 (Changes since WebStack 0.8)
208 ------------------------------------------------
209
210 * Standardised error handling in the adapters so that tracebacks can be
211 suppressed and an internal server error condition raised.
212 * Added overriding of path info in transactions.
213 * Added a ResourceMap resource for dispatching to different resources
214 according to path components.
215 * Standardised deployment for some frameworks (see docs/deploying.html).
216 * Introductory documentation in XHTML format.
217 * Added server name and port methods to the transaction.
218 * Added a simple demonstration application, incorporating many of the
219 examples and launched under a single script.
220 * Fixed mod_python native sessions.
221 * Fixed Zope request stream access.
222 * WebStack is now licensed under the LGPL - see docs/COPYING.txt for
223 details.
224
225 New in WebStack 0.8 (Changes since WebStack 0.7)
226 ------------------------------------------------
227
228 * Added a standard exception, EndOfResponse, which can be used to
229 immediately stop the processing/production of a response; this is useful
230 when resources need to issue a redirect without unnecessary content being
231 generated, for example.
232 * Fixed path information for Zope.
233 * Added WSGI support.
234 * Verified Twisted 1.3.0 support with Python 2.3.3.
235
236 New in WebStack 0.7 (Changes since WebStack 0.6)
237 ------------------------------------------------
238
239 * Fixed path information semantics.
240 * Fixed file upload semantics.
241 * Fixed content type handling for Unicode output and for interpreting
242 request body fields/parameters (although some improvement remains).
243 * Added a method to discover the chosen response stream encoding.
244 * Fixed field/parameter retrieval so that path and body fields are distinct,
245 regardless of the framework employed.
246 * Added a method to get a combination of path and body fields (suggested by
247 Jacob Smullyan).
248 * Introduced Zope 2 support.
249 * Improved Jython/Java Servlet API support (although a special PyServlet
250 class must now be used, and certain libraries must be deployed with
251 applications).
252 * Introduced authentication/authorisation support for Jython/Java Servlet
253 API.
254 * Session support has been added (except for Webware 0.8.1).
255 * Alternative cookie support for mod_python has been added.
256 * Cookie support now supports encoded Unicode sequences for names and
257 values.
258
259 New in WebStack 0.6 (Changes since WebStack 0.5)
260 ------------------------------------------------
261
262 * Introduced Jython/Java Servlet API support.
263 * Minor fixes to example applications and to BaseHTTPRequestHandler.
264
265 New in WebStack 0.5 (Changes since WebStack 0.4)
266 ------------------------------------------------
267
268 * Changed request body fields/parameters so that they are now represented
269 using Unicode objects rather than plain strings.
270 * Introduced better support for Unicode in response streams.
271
272 New in WebStack 0.4 (Changes since WebStack 0.3)
273 ------------------------------------------------
274
275 * Added application definition of user identity, permitting alternative
276 authentication mechanisms.
277 * Improved BaseHTTPRequestHandler and mod_python reliability around fields
278 from request bodies.
279 * Provided stream and environment parameterisation in the CGI adapter.
280 * Added LoginRedirect and Login examples.
281 * Added get_path_without_query and fixed get_path behaviour.
282
283 New in WebStack 0.3 (Changes since WebStack 0.2)
284 ------------------------------------------------
285
286 * Added better header support for Webware (suggested by Ian Bicking).
287 * Introduced CGI and Java Servlet support (the latter is currently
288 broken/unfinished).
289 * Introduced support for cookies.
290
291 Future Work
292 -----------
293
294 (Essential)
295
296 Twisted 1.3.0 does not provide file upload metadata, and Twisted Web 0.5.0
297 also seems to be missing this functionality. It isn't obvious whether Twisted
298 Web2 will just copy its predecessors and provide a similarly limited API.
299 Perhaps the Twisted support needs to resemble the CGI support much more when
300 handling fields.
301
302 JythonServlet libraries need to be configured using sys.add_package when
303 these do not feature in the compiled-in list. Adding such configuration to
304 the handler may be most appropriate (since the web.xml file can be too
305 arcane), but this needs testing.
306
307 The algorithm employed in the WebStack.Helpers.Auth.get_token function
308 should be reviewed and improved for better security.
309
310 (Important)
311
312 Field access needs testing, especially for anything using the
313 cgi.FieldStorage class, and the way file uploads are exposed should be
314 reviewed (currently the meta-data is not exposed). The acquisition of fields
315 from specific sources should be tested with different request methods - some
316 frameworks provide path fields in the body fields dictionary, others (eg.
317 Zope) change the fields exposed depending on request method.
318
319 Interpretation of path field encodings needs to be verified. Currently,
320 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
321 ISO-8859-1, but it might be the case that some such fields might be
322 submitted as UTF-8. The decode_path method on Transaction does do much of the
323 work that is likely to be required, however. Still, a good policy for decoding
324 path fields, reducing the number of times one might specify the encoding in
325 various method calls, may be important.
326
327 An interesting test of encodings is to introduce things like the following to
328 the path info and query string sections of the URL: %25F0?%E6=%F8&%25F0=%F8
329 This should produce the following decoded result: %F0?æ=ø&%F0=ø
330 (The above needs to be read in ISO-8859-1 or ISO-8859-15.)
331
332 Cookie objects need defining strictly, especially since the standard library
333 Cookie object behaves differently to mod_python (and possibly Webware)
334 Cookie objects. Moreover, the set_cookie_value method needs to provide
335 access to the usual cookie parameters as supported by the frameworks. The
336 standard library Cookie module has issues with Unicode cookie names (and
337 possibly values) - this is worked around, but it would be best to resolve
338 this comprehensively.
339
340 UTF-16 (and possibly other encodings) causes problems with HTML form data
341 sent in POST requests using the application/x-www-form-urlencoded content
342 type. This should be reviewed at a later date when proper standardisation
343 has taken place.
344
345 Session support, especially through WebStack.Helpers.Session, should be
346 reviewed and be made compatible with non-cookie mechanisms.
347
348 Locking in the session support and in DirectoryRepository should be improved.
349
350 HeaderValue objects should be employed more extensively. Thus, the header
351 access methods may need to change their behaviour slightly. The get_headers
352 method should potentially return a list for each item in the dictionary.
353
354 WSGI support could demand that a special "end of headers" method be
355 introduced into WebStack, thus making response output more efficient (and
356 probably also for other frameworks, too).
357
358 Investigate proper support for HEAD, OPTIONS and other request methods.
359
360 Consider packages for different operating systems (other than Debian).
361
362 Investigate cStringIO usage.
363
364 The location of deployed applications in the filesystem should be exposed to
365 those applications. (This is actually available in the __file__ module
366 variable.) A resource could be provided to record the "root" path and added to
367 a resource hierarchy or site map. Note that PathSelector records the "root"
368 path, although it is not automatically deployed.
369
370 (Completed/rejected)
371
372 Path information should be consistent across all frameworks, and the "path
373 info" value should be meaningful. (This should now be correct.)
374
375 Investigate the nicer functions in the cgi module, discarding the "magic"
376 stuff like FieldStorage. (These nicer functions are used by projects like
377 Twisted - as of 1.3.0 at least - and do not give the necessary information we
378 require.)
379
380 Release Procedures
381 ------------------
382
383 Update the WebStack/__init__.py __version__ attribute.
384 Change the version number and package filename/directory in the documentation.
385 Change code examples in the documentation if appropriate.
386 Update the release notes (see above).
387 Check the setup.py file and ensure that all package directories are mentioned.
388 Check the release information in the PKG-INFO file and in the package
389 changelog (and other files).
390 Tag, export.
391 Generate the PyServlet classes.
392 Generate the API documentation.
393 Remove generated .pyc files: rm `find . -name "*.pyc"`
394 Archive, upload.
395 Upload the introductory documentation.
396 Update PyPI, PythonInfo Wiki entries.
397
398 Generating the API Documentation
399 --------------------------------
400
401 In order to prepare the API documentation, it is necessary to generate some
402 Web pages from the Python source code. For this, the epydoc application must
403 be available on your system. Then, inside the distribution directory, run the
404 apidocs.sh tool script as follows:
405
406 ./tools/apidocs.sh
407
408 Some warnings may be generated by the script, but the result should be a new
409 apidocs directory within the distribution directory.
410
411 Making Packages
412 ---------------
413
414 To make Debian-based packages:
415
416 1. Create new package directories under packages if necessary.
417 2. Make a symbolic link in the distribution's root directory to keep the
418 Debian tools happy. For example:
419
420 ln -s packages/ubuntu-hoary/python2.4-webstack/debian/
421 ln -s packages/ubuntu-feisty/python-webstack/debian/
422
423 3. Run the package builder:
424
425 dpkg-buildpackage -rfakeroot
426
427 4. Locate and tidy up the packages in the parent directory of the
428 distribution's root directory.