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