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