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 * Improved the webstack_java_build.py script and added a deployment
45 descriptor for JSP to accompany the new Java Servlet-specific JSPTest
46 example.
47 * Added a special Java Servlet-specific get_servlet method to support the
48 JSPTest example. It is envisaged that a more general method could be made
49 available for all frameworks in order to support access to underlying
50 request dispatchers and other framework facilities.
51 * Added more Jython-related documentation as suggested by Kevin Glynn.
52 * Added missing request headers for CGI/WSGI environment variables.
53 * Fixed Webware support to work with Webware 0.9.4.
54 * Fixed/improved Zope path value retrieval.
55
56 New in WebStack 1.2.5 (Changes since WebStack 1.2.4)
57 ----------------------------------------------------
58
59 * Fixed mod_python status codes using a solution proposed by John Krukoff.
60 * Fixed a Twisted deprecation warning when accessing port numbers, thanks to
61 John Krukoff.
62 * Added Ubuntu Feisty (7.04) package support.
63 * Tidied up the documentation HTML.
64
65 New in WebStack 1.2.4 (Changes since WebStack 1.2.3)
66 ----------------------------------------------------
67
68 * Made a SessionDirectoryRepository which uses directories for data produced
69 by the shelve module, rather than attempting to manipulate files produced
70 by the shelve module, since the details of such files may differ between
71 environments: a situation noticed by John Krukoff in an environment
72 without the bsddb module installed.
73
74 New in WebStack 1.2.3 (Changes since WebStack 1.2.2)
75 ----------------------------------------------------
76
77 * Fixed inadvertent OpenSSL dependency, noticed by John Krukoff.
78
79 New in WebStack 1.2.2 (Changes since WebStack 1.2.1)
80 ----------------------------------------------------
81
82 * Added an EncodingSelector class for the setting of default encodings on
83 transactions.
84 * Added some documentation about path processing strategies.
85 * Added a secure variant of the BaseHTTPServer provided in the adapter for
86 BaseHTTPRequestHandler.
87
88 New in WebStack 1.2.1 (Changes since WebStack 1.2)
89 --------------------------------------------------
90
91 * Fixed mod_python get_content_type method.
92 * Fixed LoginResource form field processing; changed the field type to
93 password.
94 * Exposed LoginResource and LoginRedirectResource page contents as
95 attributes.
96 * Added documentation about extending LoginRedirectResource and using
97 PathSelector to remember an application's root path.
98 * Changed handle_errors to 1 throughout the examples.
99
100 New in WebStack 1.2 (Changes since WebStack 1.1.2)
101 --------------------------------------------------
102
103 * Added support for Django.
104 * Fixed documentation about the representation of file upload fields.
105 * Changed mod_python, Java Servlet and Webware (> 0.8.1) deployment to use a
106 deploy function instead of more complicated configuration mechanisms.
107 * Improved mod_python deployment documentation and tools so that cleaner
108 application paths/URLs can now be used.
109 * Moved user and path_info default definitions into WebStack.Generic as
110 class attributes.
111 * Fixed encoding usage issues with path fields when using get_fields in a
112 Zope environment.
113 * Added a FileResource class to WebStack.Resources.Static.
114 * Made DirectoryRepository convert filenames to Unicode in all cases.
115 * Renamed the Apache and Java Servlet tools, making them scripts which are
116 installed by setup.py.
117 * Fixed CGI content charsets and languages support.
118 * Fixed CGI cookie output.
119 * Added URL overriding in the LoginRedirectResource.
120 * Exposed a get_target function from WebStack.Resources.Login in order to
121 better support alternative login resources.
122 * Added improved error reporting for BaseHTTPRequestHandler, CGI, Django and
123 WSGI.
124 * Added a traverse_path method to the Transaction class.
125 * Made a path_encoding alias for urlencoding in the initialisation of
126 WebStack.Resources.ResourceMap objects.
127 * Added a Selectors module to WebStack.Resources in order to support common
128 resource selection patterns.
129
130 New in WebStack 1.1.2 (Changes since WebStack 1.1.1)
131 ----------------------------------------------------
132
133 * Fixed missing import in WebStack.Repositories.Directory.
134
135 New in WebStack 1.1.1 (Changes since WebStack 1.1)
136 --------------------------------------------------
137
138 * Fixed update_path to handle the root path properly.
139
140 New in WebStack 1.1 (Changes since WebStack 1.0)
141 ------------------------------------------------
142
143 * Added a Repositories package to provide session-like support for
144 different kinds of storage.
145 * Added an explicit filesystem encoding to the Calendar example and adopted
146 the DirectoryRepository from the Repositories package.
147 * Added get_path_without_info, update_path and redirect methods to the
148 Transaction class.
149 * Added get_attributes (attribute support) to the Transaction class.
150 * Added a values method to Helpers.Session.Wrapper.
151 * Fixed get_processed_virtual_path_info (to match from right to left).
152 * Improved/fixed exception handling in the adapters so that transactions are
153 committed as the final act of an adapter experiencing an unhandled
154 exception. This should result in session stores being closed properly.
155 * Changed the Helpers.Session.SessionStore to use DirectoryRepository.
156 * Made the "not found" behaviour of DirectoryResource more configurable.
157 * Added documentation for MapResource and DirectoryResource.
158 * Fixed the distribution names in the Ubuntu changelog.
159
160 New in WebStack 1.0 (Changes since WebStack 0.10)
161 -------------------------------------------------
162
163 * Changed the behaviour of get_path, get_path_without_query, get_path_info,
164 get_virtual_path_info, get_processed_virtual_path_info and
165 get_fields_from_path to return Unicode data decoded using the optional
166 encoding parameter or a common default encoding.
167 * Fixed file upload values so that FileContent objects are returned for such
168 fields in get_fields_from_body and get_fields.
169 (Warning! Except for Twisted!)
170 * Fixed the JavaServlet support so that streams and file content are
171 obtained as "almost" plain strings.
172 * Updated/fixed LoginResource and LoginRedirectResource to use the updated
173 path API and to handle special characters properly.
174 * Added convenience methods to Transaction for the decoding and encoding of
175 path values (to and from Unicode objects) - see the decode_path and
176 encode_path methods.
177 * Added the notion of processed virtual path info - the part of the original
178 path info not represented in the current virtual path info.
179 * Added "pass through" behaviour to ResourceMap.MapResource (prompted by a
180 patch from Scott Robinson).
181 * Fixed ResourceMap.MapResource to handle non-existent resources properly
182 (where the virtual path info is only one component in length).
183 * Added Debian package support.
184 * Added automatic session directory creation for the WebStack sessions
185 implementation.
186 * Added support for the repeated retrieval of sessions from the same
187 WebStack session store, avoiding deadlocks.
188 * Fixed the calendar example, making it perform a proper function.
189 * Made the BaseHTTPRequestHandler and Twisted SimpleWithLogin applications
190 include the Login application, since Konqueror (at least) does not share
191 cookies across different port numbers on the same host.
192 * Added the SimpleWithLogin and Login applications to the demonstration.
193 * Improved the documentation, adding information on request headers, and
194 describing file upload and session support limitations.
195 * Improved the AOLserver-related notes for CGI and Webware, adding a patch
196 for Webware in order to work around AOLserver issues.
197
198 New in WebStack 0.10 (Changes since WebStack 0.9)
199 -------------------------------------------------
200
201 * Changes to make the tools/demo.py script work on Windows (and other)
202 platforms (suggested by Jim Madsen).
203 * Fixed end of header newlines for CGI (suggested by Matt Harrison).
204 * Minor documentation fixes and improvements, adding information on
205 AOLserver in the CGI and Webware notes.
206 * Changed the mod_python server name method to use the server object rather
207 than the connection object.
208 * Added a parameter to the ResourceMap.MapResource class to permit automatic
209 redirects into resource hierarchies when no trailing "/" was given in the
210 URL; changed the updated virtual path info so that empty values may be set
211 (the guarantee that "/" will always appear no longer applies).
212 * Fixed virtual path info retrieval when the value is an empty string.
213
214 New in WebStack 0.9 (Changes since WebStack 0.8)
215 ------------------------------------------------
216
217 * Standardised error handling in the adapters so that tracebacks can be
218 suppressed and an internal server error condition raised.
219 * Added overriding of path info in transactions.
220 * Added a ResourceMap resource for dispatching to different resources
221 according to path components.
222 * Standardised deployment for some frameworks (see docs/deploying.html).
223 * Introductory documentation in XHTML format.
224 * Added server name and port methods to the transaction.
225 * Added a simple demonstration application, incorporating many of the
226 examples and launched under a single script.
227 * Fixed mod_python native sessions.
228 * Fixed Zope request stream access.
229 * WebStack is now licensed under the LGPL - see docs/COPYING.txt for
230 details.
231
232 New in WebStack 0.8 (Changes since WebStack 0.7)
233 ------------------------------------------------
234
235 * Added a standard exception, EndOfResponse, which can be used to
236 immediately stop the processing/production of a response; this is useful
237 when resources need to issue a redirect without unnecessary content being
238 generated, for example.
239 * Fixed path information for Zope.
240 * Added WSGI support.
241 * Verified Twisted 1.3.0 support with Python 2.3.3.
242
243 New in WebStack 0.7 (Changes since WebStack 0.6)
244 ------------------------------------------------
245
246 * Fixed path information semantics.
247 * Fixed file upload semantics.
248 * Fixed content type handling for Unicode output and for interpreting
249 request body fields/parameters (although some improvement remains).
250 * Added a method to discover the chosen response stream encoding.
251 * Fixed field/parameter retrieval so that path and body fields are distinct,
252 regardless of the framework employed.
253 * Added a method to get a combination of path and body fields (suggested by
254 Jacob Smullyan).
255 * Introduced Zope 2 support.
256 * Improved Jython/Java Servlet API support (although a special PyServlet
257 class must now be used, and certain libraries must be deployed with
258 applications).
259 * Introduced authentication/authorisation support for Jython/Java Servlet
260 API.
261 * Session support has been added (except for Webware 0.8.1).
262 * Alternative cookie support for mod_python has been added.
263 * Cookie support now supports encoded Unicode sequences for names and
264 values.
265
266 New in WebStack 0.6 (Changes since WebStack 0.5)
267 ------------------------------------------------
268
269 * Introduced Jython/Java Servlet API support.
270 * Minor fixes to example applications and to BaseHTTPRequestHandler.
271
272 New in WebStack 0.5 (Changes since WebStack 0.4)
273 ------------------------------------------------
274
275 * Changed request body fields/parameters so that they are now represented
276 using Unicode objects rather than plain strings.
277 * Introduced better support for Unicode in response streams.
278
279 New in WebStack 0.4 (Changes since WebStack 0.3)
280 ------------------------------------------------
281
282 * Added application definition of user identity, permitting alternative
283 authentication mechanisms.
284 * Improved BaseHTTPRequestHandler and mod_python reliability around fields
285 from request bodies.
286 * Provided stream and environment parameterisation in the CGI adapter.
287 * Added LoginRedirect and Login examples.
288 * Added get_path_without_query and fixed get_path behaviour.
289
290 New in WebStack 0.3 (Changes since WebStack 0.2)
291 ------------------------------------------------
292
293 * Added better header support for Webware (suggested by Ian Bicking).
294 * Introduced CGI and Java Servlet support (the latter is currently
295 broken/unfinished).
296 * Introduced support for cookies.
297
298 Future Work
299 -----------
300
301 (Essential)
302
303 Twisted 1.3.0 does not provide file upload metadata, and Twisted Web 0.5.0
304 also seems to be missing this functionality. It isn't obvious whether Twisted
305 Web2 will just copy its predecessors and provide a similarly limited API.
306 Perhaps the Twisted support needs to resemble the CGI support much more when
307 handling fields.
308
309 JythonServlet libraries need to be configured using sys.add_package when
310 these do not feature in the compiled-in list. Adding such configuration to
311 the handler may be most appropriate (since the web.xml file can be too
312 arcane), but this needs testing.
313
314 The algorithm employed in the WebStack.Helpers.Auth.get_token function
315 should be reviewed and improved for better security.
316
317 (Important)
318
319 Field access needs testing, especially for anything using the
320 cgi.FieldStorage class, and the way file uploads are exposed should be
321 reviewed (currently the meta-data is not exposed). The acquisition of fields
322 from specific sources should be tested with different request methods - some
323 frameworks provide path fields in the body fields dictionary, others (eg.
324 Zope) change the fields exposed depending on request method.
325
326 Interpretation of path field encodings needs to be verified. Currently,
327 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
328 ISO-8859-1, but it might be the case that some such fields might be
329 submitted as UTF-8. The decode_path method on Transaction does do much of the
330 work that is likely to be required, however. Still, a good policy for decoding
331 path fields, reducing the number of times one might specify the encoding in
332 various method calls, may be important.
333
334 An interesting test of encodings is to introduce things like the following to
335 the path info and query string sections of the URL: %25F0?%E6=%F8&%25F0=%F8
336 This should produce the following decoded result: %F0?æ=ø&%F0=ø
337 (The above needs to be read in ISO-8859-1 or ISO-8859-15.)
338
339 Cookie objects need defining strictly, especially since the standard library
340 Cookie object behaves differently to mod_python (and possibly Webware)
341 Cookie objects. Moreover, the set_cookie_value method needs to provide
342 access to the usual cookie parameters as supported by the frameworks. The
343 standard library Cookie module has issues with Unicode cookie names (and
344 possibly values) - this is worked around, but it would be best to resolve
345 this comprehensively.
346
347 UTF-16 (and possibly other encodings) causes problems with HTML form data
348 sent in POST requests using the application/x-www-form-urlencoded content
349 type. This should be reviewed at a later date when proper standardisation
350 has taken place.
351
352 Session support, especially through WebStack.Helpers.Session, should be
353 reviewed and be made compatible with non-cookie mechanisms.
354
355 Locking in the session support and in DirectoryRepository should be improved.
356
357 HeaderValue objects should be employed more extensively. Thus, the header
358 access methods may need to change their behaviour slightly. The get_headers
359 method should potentially return a list for each item in the dictionary.
360
361 WSGI support could demand that a special "end of headers" method be
362 introduced into WebStack, thus making response output more efficient (and
363 probably also for other frameworks, too).
364
365 Investigate proper support for HEAD, OPTIONS and other request methods.
366
367 Consider packages for different operating systems (other than Debian).
368
369 Investigate cStringIO usage.
370
371 The location of deployed applications in the filesystem should be exposed to
372 those applications. (This is actually available in the __file__ module
373 variable.) A resource could be provided to record the "root" path and added to
374 a resource hierarchy or site map. Note that PathSelector records the "root"
375 path, although it is not automatically deployed.
376
377 (Completed/rejected)
378
379 Path information should be consistent across all frameworks, and the "path
380 info" value should be meaningful. (This should now be correct.)
381
382 Investigate the nicer functions in the cgi module, discarding the "magic"
383 stuff like FieldStorage. (These nicer functions are used by projects like
384 Twisted - as of 1.3.0 at least - and do not give the necessary information we
385 require.)
386
387 Release Procedures
388 ------------------
389
390 Update the WebStack/__init__.py __version__ attribute.
391 Change the version number and package filename/directory in the documentation.
392 Change code examples in the documentation if appropriate.
393 Update the release notes (see above).
394 Check the setup.py file and ensure that all package directories are mentioned.
395 Check the release information in the PKG-INFO file and in the package
396 changelog (and other files).
397 Tag, export.
398 Generate the PyServlet classes.
399 Generate the API documentation.
400 Remove generated .pyc files: rm `find . -name "*.pyc"`
401 Archive, upload.
402 Upload the introductory documentation.
403 Update PyPI, PythonInfo Wiki entries.
404
405 Generating the API Documentation
406 --------------------------------
407
408 In order to prepare the API documentation, it is necessary to generate some
409 Web pages from the Python source code. For this, the epydoc application must
410 be available on your system. Then, inside the distribution directory, run the
411 apidocs.sh tool script as follows:
412
413 ./tools/apidocs.sh
414
415 Some warnings may be generated by the script, but the result should be a new
416 apidocs directory within the distribution directory.
417
418 Making Packages
419 ---------------
420
421 To make Debian-based packages:
422
423 1. Create new package directories under packages if necessary.
424 2. Make a symbolic link in the distribution's root directory to keep the
425 Debian tools happy. For example:
426
427 ln -s packages/ubuntu-hoary/python2.4-webstack/debian/
428 ln -s packages/ubuntu-feisty/python-webstack/debian/
429
430 3. Run the package builder:
431
432 dpkg-buildpackage -rfakeroot
433
434 4. Locate and tidy up the packages in the parent directory of the
435 distribution's root directory.