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