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 * Added a jython-webstack package for Ubuntu Feisty (7.04).
41 * Improved support for Jython on Ubuntu Feisty (7.04), adding python.path
42 and python.cachedir settings which respectively avoid issues with missing
43 libraries (due to the separation of libraries in the Ubuntu package) and
44 with failed imports (due to a read-only class cache directory).
45 * Improved the webstack_java_build.py script and added a deployment
46 descriptor for JSP to accompany the new Java Servlet-specific JSPTest
47 example.
48 * Added a special Java Servlet-specific get_servlet method to support the
49 JSPTest example. It is envisaged that a more general method could be made
50 available for all frameworks in order to support access to underlying
51 request dispatchers and other framework facilities.
52 * Added more Jython-related documentation as suggested by Kevin Glynn.
53 * Added missing request headers for CGI/WSGI environment variables.
54 * Fixed Webware support to work with Webware 0.9.4.
55 * Fixed/improved Zope path value retrieval.
56 * Added support for wsgiref, changing the WSGI deploy function for CGI-based
57 applications to deploy_as_cgi and adding a deploy_with_wsgiref function.
58
59 New in WebStack 1.2.5 (Changes since WebStack 1.2.4)
60 ----------------------------------------------------
61
62 * Fixed mod_python status codes using a solution proposed by John Krukoff.
63 * Fixed a Twisted deprecation warning when accessing port numbers, thanks to
64 John Krukoff.
65 * Added Ubuntu Feisty (7.04) package support.
66 * Tidied up the documentation HTML.
67
68 New in WebStack 1.2.4 (Changes since WebStack 1.2.3)
69 ----------------------------------------------------
70
71 * Made a SessionDirectoryRepository which uses directories for data produced
72 by the shelve module, rather than attempting to manipulate files produced
73 by the shelve module, since the details of such files may differ between
74 environments: a situation noticed by John Krukoff in an environment
75 without the bsddb module installed.
76
77 New in WebStack 1.2.3 (Changes since WebStack 1.2.2)
78 ----------------------------------------------------
79
80 * Fixed inadvertent OpenSSL dependency, noticed by John Krukoff.
81
82 New in WebStack 1.2.2 (Changes since WebStack 1.2.1)
83 ----------------------------------------------------
84
85 * Added an EncodingSelector class for the setting of default encodings on
86 transactions.
87 * Added some documentation about path processing strategies.
88 * Added a secure variant of the BaseHTTPServer provided in the adapter for
89 BaseHTTPRequestHandler.
90
91 New in WebStack 1.2.1 (Changes since WebStack 1.2)
92 --------------------------------------------------
93
94 * Fixed mod_python get_content_type method.
95 * Fixed LoginResource form field processing; changed the field type to
96 password.
97 * Exposed LoginResource and LoginRedirectResource page contents as
98 attributes.
99 * Added documentation about extending LoginRedirectResource and using
100 PathSelector to remember an application's root path.
101 * Changed handle_errors to 1 throughout the examples.
102
103 New in WebStack 1.2 (Changes since WebStack 1.1.2)
104 --------------------------------------------------
105
106 * Added support for Django.
107 * Fixed documentation about the representation of file upload fields.
108 * Changed mod_python, Java Servlet and Webware (> 0.8.1) deployment to use a
109 deploy function instead of more complicated configuration mechanisms.
110 * Improved mod_python deployment documentation and tools so that cleaner
111 application paths/URLs can now be used.
112 * Moved user and path_info default definitions into WebStack.Generic as
113 class attributes.
114 * Fixed encoding usage issues with path fields when using get_fields in a
115 Zope environment.
116 * Added a FileResource class to WebStack.Resources.Static.
117 * Made DirectoryRepository convert filenames to Unicode in all cases.
118 * Renamed the Apache and Java Servlet tools, making them scripts which are
119 installed by setup.py.
120 * Fixed CGI content charsets and languages support.
121 * Fixed CGI cookie output.
122 * Added URL overriding in the LoginRedirectResource.
123 * Exposed a get_target function from WebStack.Resources.Login in order to
124 better support alternative login resources.
125 * Added improved error reporting for BaseHTTPRequestHandler, CGI, Django and
126 WSGI.
127 * Added a traverse_path method to the Transaction class.
128 * Made a path_encoding alias for urlencoding in the initialisation of
129 WebStack.Resources.ResourceMap objects.
130 * Added a Selectors module to WebStack.Resources in order to support common
131 resource selection patterns.
132
133 New in WebStack 1.1.2 (Changes since WebStack 1.1.1)
134 ----------------------------------------------------
135
136 * Fixed missing import in WebStack.Repositories.Directory.
137
138 New in WebStack 1.1.1 (Changes since WebStack 1.1)
139 --------------------------------------------------
140
141 * Fixed update_path to handle the root path properly.
142
143 New in WebStack 1.1 (Changes since WebStack 1.0)
144 ------------------------------------------------
145
146 * Added a Repositories package to provide session-like support for
147 different kinds of storage.
148 * Added an explicit filesystem encoding to the Calendar example and adopted
149 the DirectoryRepository from the Repositories package.
150 * Added get_path_without_info, update_path and redirect methods to the
151 Transaction class.
152 * Added get_attributes (attribute support) to the Transaction class.
153 * Added a values method to Helpers.Session.Wrapper.
154 * Fixed get_processed_virtual_path_info (to match from right to left).
155 * Improved/fixed exception handling in the adapters so that transactions are
156 committed as the final act of an adapter experiencing an unhandled
157 exception. This should result in session stores being closed properly.
158 * Changed the Helpers.Session.SessionStore to use DirectoryRepository.
159 * Made the "not found" behaviour of DirectoryResource more configurable.
160 * Added documentation for MapResource and DirectoryResource.
161 * Fixed the distribution names in the Ubuntu changelog.
162
163 New in WebStack 1.0 (Changes since WebStack 0.10)
164 -------------------------------------------------
165
166 * Changed the behaviour of get_path, get_path_without_query, get_path_info,
167 get_virtual_path_info, get_processed_virtual_path_info and
168 get_fields_from_path to return Unicode data decoded using the optional
169 encoding parameter or a common default encoding.
170 * Fixed file upload values so that FileContent objects are returned for such
171 fields in get_fields_from_body and get_fields.
172 (Warning! Except for Twisted!)
173 * Fixed the JavaServlet support so that streams and file content are
174 obtained as "almost" plain strings.
175 * Updated/fixed LoginResource and LoginRedirectResource to use the updated
176 path API and to handle special characters properly.
177 * Added convenience methods to Transaction for the decoding and encoding of
178 path values (to and from Unicode objects) - see the decode_path and
179 encode_path methods.
180 * Added the notion of processed virtual path info - the part of the original
181 path info not represented in the current virtual path info.
182 * Added "pass through" behaviour to ResourceMap.MapResource (prompted by a
183 patch from Scott Robinson).
184 * Fixed ResourceMap.MapResource to handle non-existent resources properly
185 (where the virtual path info is only one component in length).
186 * Added Debian package support.
187 * Added automatic session directory creation for the WebStack sessions
188 implementation.
189 * Added support for the repeated retrieval of sessions from the same
190 WebStack session store, avoiding deadlocks.
191 * Fixed the calendar example, making it perform a proper function.
192 * Made the BaseHTTPRequestHandler and Twisted SimpleWithLogin applications
193 include the Login application, since Konqueror (at least) does not share
194 cookies across different port numbers on the same host.
195 * Added the SimpleWithLogin and Login applications to the demonstration.
196 * Improved the documentation, adding information on request headers, and
197 describing file upload and session support limitations.
198 * Improved the AOLserver-related notes for CGI and Webware, adding a patch
199 for Webware in order to work around AOLserver issues.
200
201 New in WebStack 0.10 (Changes since WebStack 0.9)
202 -------------------------------------------------
203
204 * Changes to make the tools/demo.py script work on Windows (and other)
205 platforms (suggested by Jim Madsen).
206 * Fixed end of header newlines for CGI (suggested by Matt Harrison).
207 * Minor documentation fixes and improvements, adding information on
208 AOLserver in the CGI and Webware notes.
209 * Changed the mod_python server name method to use the server object rather
210 than the connection object.
211 * Added a parameter to the ResourceMap.MapResource class to permit automatic
212 redirects into resource hierarchies when no trailing "/" was given in the
213 URL; changed the updated virtual path info so that empty values may be set
214 (the guarantee that "/" will always appear no longer applies).
215 * Fixed virtual path info retrieval when the value is an empty string.
216
217 New in WebStack 0.9 (Changes since WebStack 0.8)
218 ------------------------------------------------
219
220 * Standardised error handling in the adapters so that tracebacks can be
221 suppressed and an internal server error condition raised.
222 * Added overriding of path info in transactions.
223 * Added a ResourceMap resource for dispatching to different resources
224 according to path components.
225 * Standardised deployment for some frameworks (see docs/deploying.html).
226 * Introductory documentation in XHTML format.
227 * Added server name and port methods to the transaction.
228 * Added a simple demonstration application, incorporating many of the
229 examples and launched under a single script.
230 * Fixed mod_python native sessions.
231 * Fixed Zope request stream access.
232 * WebStack is now licensed under the LGPL - see docs/COPYING.txt for
233 details.
234
235 New in WebStack 0.8 (Changes since WebStack 0.7)
236 ------------------------------------------------
237
238 * Added a standard exception, EndOfResponse, which can be used to
239 immediately stop the processing/production of a response; this is useful
240 when resources need to issue a redirect without unnecessary content being
241 generated, for example.
242 * Fixed path information for Zope.
243 * Added WSGI support.
244 * Verified Twisted 1.3.0 support with Python 2.3.3.
245
246 New in WebStack 0.7 (Changes since WebStack 0.6)
247 ------------------------------------------------
248
249 * Fixed path information semantics.
250 * Fixed file upload semantics.
251 * Fixed content type handling for Unicode output and for interpreting
252 request body fields/parameters (although some improvement remains).
253 * Added a method to discover the chosen response stream encoding.
254 * Fixed field/parameter retrieval so that path and body fields are distinct,
255 regardless of the framework employed.
256 * Added a method to get a combination of path and body fields (suggested by
257 Jacob Smullyan).
258 * Introduced Zope 2 support.
259 * Improved Jython/Java Servlet API support (although a special PyServlet
260 class must now be used, and certain libraries must be deployed with
261 applications).
262 * Introduced authentication/authorisation support for Jython/Java Servlet
263 API.
264 * Session support has been added (except for Webware 0.8.1).
265 * Alternative cookie support for mod_python has been added.
266 * Cookie support now supports encoded Unicode sequences for names and
267 values.
268
269 New in WebStack 0.6 (Changes since WebStack 0.5)
270 ------------------------------------------------
271
272 * Introduced Jython/Java Servlet API support.
273 * Minor fixes to example applications and to BaseHTTPRequestHandler.
274
275 New in WebStack 0.5 (Changes since WebStack 0.4)
276 ------------------------------------------------
277
278 * Changed request body fields/parameters so that they are now represented
279 using Unicode objects rather than plain strings.
280 * Introduced better support for Unicode in response streams.
281
282 New in WebStack 0.4 (Changes since WebStack 0.3)
283 ------------------------------------------------
284
285 * Added application definition of user identity, permitting alternative
286 authentication mechanisms.
287 * Improved BaseHTTPRequestHandler and mod_python reliability around fields
288 from request bodies.
289 * Provided stream and environment parameterisation in the CGI adapter.
290 * Added LoginRedirect and Login examples.
291 * Added get_path_without_query and fixed get_path behaviour.
292
293 New in WebStack 0.3 (Changes since WebStack 0.2)
294 ------------------------------------------------
295
296 * Added better header support for Webware (suggested by Ian Bicking).
297 * Introduced CGI and Java Servlet support (the latter is currently
298 broken/unfinished).
299 * Introduced support for cookies.
300
301 Future Work
302 -----------
303
304 (Essential)
305
306 Twisted 1.3.0 does not provide file upload metadata, and Twisted Web 0.5.0
307 also seems to be missing this functionality. It isn't obvious whether Twisted
308 Web2 will just copy its predecessors and provide a similarly limited API.
309 Perhaps the Twisted support needs to resemble the CGI support much more when
310 handling fields.
311
312 JythonServlet libraries need to be configured using sys.add_package when
313 these do not feature in the compiled-in list. Adding such configuration to
314 the handler may be most appropriate (since the web.xml file can be too
315 arcane), but this needs testing.
316
317 The algorithm employed in the WebStack.Helpers.Auth.get_token function
318 should be reviewed and improved for better security.
319
320 (Important)
321
322 Field access needs testing, especially for anything using the
323 cgi.FieldStorage class, and the way file uploads are exposed should be
324 reviewed (currently the meta-data is not exposed). The acquisition of fields
325 from specific sources should be tested with different request methods - some
326 frameworks provide path fields in the body fields dictionary, others (eg.
327 Zope) change the fields exposed depending on request method.
328
329 Interpretation of path field encodings needs to be verified. Currently,
330 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
331 ISO-8859-1, but it might be the case that some such fields might be
332 submitted as UTF-8. The decode_path method on Transaction does do much of the
333 work that is likely to be required, however. Still, a good policy for decoding
334 path fields, reducing the number of times one might specify the encoding in
335 various method calls, may be important.
336
337 An interesting test of encodings is to introduce things like the following to
338 the path info and query string sections of the URL: %25F0?%E6=%F8&%25F0=%F8
339 This should produce the following decoded result: %F0?æ=ø&%F0=ø
340 (The above needs to be read in ISO-8859-1 or ISO-8859-15.)
341
342 Cookie objects need defining strictly, especially since the standard library
343 Cookie object behaves differently to mod_python (and possibly Webware)
344 Cookie objects. Moreover, the set_cookie_value method needs to provide
345 access to the usual cookie parameters as supported by the frameworks. The
346 standard library Cookie module has issues with Unicode cookie names (and
347 possibly values) - this is worked around, but it would be best to resolve
348 this comprehensively.
349
350 UTF-16 (and possibly other encodings) causes problems with HTML form data
351 sent in POST requests using the application/x-www-form-urlencoded content
352 type. This should be reviewed at a later date when proper standardisation
353 has taken place.
354
355 Session support, especially through WebStack.Helpers.Session, should be
356 reviewed and be made compatible with non-cookie mechanisms.
357
358 Locking in the session support and in DirectoryRepository should be improved.
359
360 HeaderValue objects should be employed more extensively. Thus, the header
361 access methods may need to change their behaviour slightly. The get_headers
362 method should potentially return a list for each item in the dictionary.
363
364 WSGI support could demand that a special "end of headers" method be
365 introduced into WebStack, thus making response output more efficient (and
366 probably also for other frameworks, too).
367
368 Investigate proper support for HEAD, OPTIONS and other request methods.
369
370 Consider packages for different operating systems (other than Debian).
371
372 Investigate cStringIO usage.
373
374 The location of deployed applications in the filesystem should be exposed to
375 those applications. (This is actually available in the __file__ module
376 variable.) A resource could be provided to record the "root" path and added to
377 a resource hierarchy or site map. Note that PathSelector records the "root"
378 path, although it is not automatically deployed.
379
380 (Completed/rejected)
381
382 Path information should be consistent across all frameworks, and the "path
383 info" value should be meaningful. (This should now be correct.)
384
385 Investigate the nicer functions in the cgi module, discarding the "magic"
386 stuff like FieldStorage. (These nicer functions are used by projects like
387 Twisted - as of 1.3.0 at least - and do not give the necessary information we
388 require.)
389
390 Release Procedures
391 ------------------
392
393 Update the WebStack/__init__.py __version__ attribute.
394 Change the version number and package filename/directory in the documentation.
395 Change code examples in the documentation if appropriate.
396 Update the release notes (see above).
397 Check the setup.py file and ensure that all package directories are mentioned.
398 Check the release information in the PKG-INFO file and in the package
399 changelog (and other files).
400 Tag, export.
401 Generate the PyServlet classes.
402 Generate the API documentation.
403 Remove generated .pyc files: rm `find . -name "*.pyc"`
404 Archive, upload.
405 Upload the introductory documentation.
406 Update PyPI, PythonInfo Wiki entries.
407
408 Generating the PyServlet Classes
409 --------------------------------
410
411 In order to generate the PyServlet classes, it is necessary to run the
412 supplied script:
413
414 ./tools/JavaServlet/compile.sh
415
416 This produces Java classes and a .jar file for use by WebStack applications
417 running on the Java platform.
418
419 Generating the API Documentation
420 --------------------------------
421
422 In order to prepare the API documentation, it is necessary to generate some
423 Web pages from the Python source code. For this, the epydoc application must
424 be available on your system. Then, inside the distribution directory, run the
425 apidocs.sh tool script as follows:
426
427 ./tools/apidocs.sh
428
429 Some warnings may be generated by the script, but the result should be a new
430 apidocs directory within the distribution directory.
431
432 Making Packages
433 ---------------
434
435 To make Debian-based packages:
436
437 1. Create new package directories under packages if necessary.
438 2. Make a symbolic link in the distribution's root directory to keep the
439 Debian tools happy. For example:
440
441 ln -s packages/ubuntu-hoary/python2.4-webstack/debian/
442 ln -s packages/ubuntu-feisty/python-webstack/debian/
443
444 3. Run the package builder:
445
446 dpkg-buildpackage -rfakeroot
447
448 4. Locate and tidy up the packages in the parent directory of the
449 distribution's root directory.