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