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 1.2.7 (Changes since WebStack 1.2.6)
38 ----------------------------------------------------
39
40 * Fixed the MessageBodyStream class, adding an optional parameter to the
41 readline method which seems to be necessary when handling multipart
42 requests.
43 * Introduced stream usage for file uploads where possible, in order to
44 reduce memory usage (suggested by Kevin Glynn), adding a stream attribute
45 to the FileContent class and making the content attribute a property.
46 * Removed error handling in the examples in order to make troubleshooting
47 easier.
48 * Fixed header issues by introducing a special HeaderDict class which
49 enforces the case-insensitivity expected of header dictionaries.
50
51 New in WebStack 1.2.6 (Changes since WebStack 1.2.5)
52 ----------------------------------------------------
53
54 * Added a jython-webstack package for Ubuntu Feisty (7.04).
55 * Improved support for Jython on Ubuntu Feisty (7.04), adding python.path
56 and python.cachedir settings which respectively avoid issues with missing
57 libraries (due to the separation of libraries in the Ubuntu package) and
58 with failed imports (due to a read-only class cache directory).
59 * Improved the webstack_java_build.py script and added a deployment
60 descriptor for JSP to accompany the new Java Servlet-specific JSPTest
61 example.
62 * Added a special Java Servlet-specific get_servlet method to support the
63 JSPTest example. It is envisaged that a more general method could be made
64 available for all frameworks in order to support access to underlying
65 request dispatchers and other framework facilities.
66 * Added more Jython-related documentation as suggested by Kevin Glynn.
67 * Added missing request headers for CGI/WSGI environment variables.
68 * Fixed Webware support to work with Webware 0.9.4.
69 * Fixed/improved Zope path value retrieval.
70 * Added support for wsgiref, changing the WSGI deploy function for CGI-based
71 applications to deploy_as_cgi and adding a deploy_with_wsgiref function.
72
73 New in WebStack 1.2.5 (Changes since WebStack 1.2.4)
74 ----------------------------------------------------
75
76 * Fixed mod_python status codes using a solution proposed by John Krukoff.
77 * Fixed a Twisted deprecation warning when accessing port numbers, thanks to
78 John Krukoff.
79 * Added Ubuntu Feisty (7.04) package support.
80 * Tidied up the documentation HTML.
81
82 New in WebStack 1.2.4 (Changes since WebStack 1.2.3)
83 ----------------------------------------------------
84
85 * Made a SessionDirectoryRepository which uses directories for data produced
86 by the shelve module, rather than attempting to manipulate files produced
87 by the shelve module, since the details of such files may differ between
88 environments: a situation noticed by John Krukoff in an environment
89 without the bsddb module installed.
90
91 New in WebStack 1.2.3 (Changes since WebStack 1.2.2)
92 ----------------------------------------------------
93
94 * Fixed inadvertent OpenSSL dependency, noticed by John Krukoff.
95
96 New in WebStack 1.2.2 (Changes since WebStack 1.2.1)
97 ----------------------------------------------------
98
99 * Added an EncodingSelector class for the setting of default encodings on
100 transactions.
101 * Added some documentation about path processing strategies.
102 * Added a secure variant of the BaseHTTPServer provided in the adapter for
103 BaseHTTPRequestHandler.
104
105 New in WebStack 1.2.1 (Changes since WebStack 1.2)
106 --------------------------------------------------
107
108 * Fixed mod_python get_content_type method.
109 * Fixed LoginResource form field processing; changed the field type to
110 password.
111 * Exposed LoginResource and LoginRedirectResource page contents as
112 attributes.
113 * Added documentation about extending LoginRedirectResource and using
114 PathSelector to remember an application's root path.
115 * Changed handle_errors to 1 throughout the examples.
116
117 New in WebStack 1.2 (Changes since WebStack 1.1.2)
118 --------------------------------------------------
119
120 * Added support for Django.
121 * Fixed documentation about the representation of file upload fields.
122 * Changed mod_python, Java Servlet and Webware (> 0.8.1) deployment to use a
123 deploy function instead of more complicated configuration mechanisms.
124 * Improved mod_python deployment documentation and tools so that cleaner
125 application paths/URLs can now be used.
126 * Moved user and path_info default definitions into WebStack.Generic as
127 class attributes.
128 * Fixed encoding usage issues with path fields when using get_fields in a
129 Zope environment.
130 * Added a FileResource class to WebStack.Resources.Static.
131 * Made DirectoryRepository convert filenames to Unicode in all cases.
132 * Renamed the Apache and Java Servlet tools, making them scripts which are
133 installed by setup.py.
134 * Fixed CGI content charsets and languages support.
135 * Fixed CGI cookie output.
136 * Added URL overriding in the LoginRedirectResource.
137 * Exposed a get_target function from WebStack.Resources.Login in order to
138 better support alternative login resources.
139 * Added improved error reporting for BaseHTTPRequestHandler, CGI, Django and
140 WSGI.
141 * Added a traverse_path method to the Transaction class.
142 * Made a path_encoding alias for urlencoding in the initialisation of
143 WebStack.Resources.ResourceMap objects.
144 * Added a Selectors module to WebStack.Resources in order to support common
145 resource selection patterns.
146
147 New in WebStack 1.1.2 (Changes since WebStack 1.1.1)
148 ----------------------------------------------------
149
150 * Fixed missing import in WebStack.Repositories.Directory.
151
152 New in WebStack 1.1.1 (Changes since WebStack 1.1)
153 --------------------------------------------------
154
155 * Fixed update_path to handle the root path properly.
156
157 New in WebStack 1.1 (Changes since WebStack 1.0)
158 ------------------------------------------------
159
160 * Added a Repositories package to provide session-like support for
161 different kinds of storage.
162 * Added an explicit filesystem encoding to the Calendar example and adopted
163 the DirectoryRepository from the Repositories package.
164 * Added get_path_without_info, update_path and redirect methods to the
165 Transaction class.
166 * Added get_attributes (attribute support) to the Transaction class.
167 * Added a values method to Helpers.Session.Wrapper.
168 * Fixed get_processed_virtual_path_info (to match from right to left).
169 * Improved/fixed exception handling in the adapters so that transactions are
170 committed as the final act of an adapter experiencing an unhandled
171 exception. This should result in session stores being closed properly.
172 * Changed the Helpers.Session.SessionStore to use DirectoryRepository.
173 * Made the "not found" behaviour of DirectoryResource more configurable.
174 * Added documentation for MapResource and DirectoryResource.
175 * Fixed the distribution names in the Ubuntu changelog.
176
177 New in WebStack 1.0 (Changes since WebStack 0.10)
178 -------------------------------------------------
179
180 * Changed the behaviour of get_path, get_path_without_query, get_path_info,
181 get_virtual_path_info, get_processed_virtual_path_info and
182 get_fields_from_path to return Unicode data decoded using the optional
183 encoding parameter or a common default encoding.
184 * Fixed file upload values so that FileContent objects are returned for such
185 fields in get_fields_from_body and get_fields.
186 (Warning! Except for Twisted!)
187 * Fixed the JavaServlet support so that streams and file content are
188 obtained as "almost" plain strings.
189 * Updated/fixed LoginResource and LoginRedirectResource to use the updated
190 path API and to handle special characters properly.
191 * Added convenience methods to Transaction for the decoding and encoding of
192 path values (to and from Unicode objects) - see the decode_path and
193 encode_path methods.
194 * Added the notion of processed virtual path info - the part of the original
195 path info not represented in the current virtual path info.
196 * Added "pass through" behaviour to ResourceMap.MapResource (prompted by a
197 patch from Scott Robinson).
198 * Fixed ResourceMap.MapResource to handle non-existent resources properly
199 (where the virtual path info is only one component in length).
200 * Added Debian package support.
201 * Added automatic session directory creation for the WebStack sessions
202 implementation.
203 * Added support for the repeated retrieval of sessions from the same
204 WebStack session store, avoiding deadlocks.
205 * Fixed the calendar example, making it perform a proper function.
206 * Made the BaseHTTPRequestHandler and Twisted SimpleWithLogin applications
207 include the Login application, since Konqueror (at least) does not share
208 cookies across different port numbers on the same host.
209 * Added the SimpleWithLogin and Login applications to the demonstration.
210 * Improved the documentation, adding information on request headers, and
211 describing file upload and session support limitations.
212 * Improved the AOLserver-related notes for CGI and Webware, adding a patch
213 for Webware in order to work around AOLserver issues.
214
215 New in WebStack 0.10 (Changes since WebStack 0.9)
216 -------------------------------------------------
217
218 * Changes to make the tools/demo.py script work on Windows (and other)
219 platforms (suggested by Jim Madsen).
220 * Fixed end of header newlines for CGI (suggested by Matt Harrison).
221 * Minor documentation fixes and improvements, adding information on
222 AOLserver in the CGI and Webware notes.
223 * Changed the mod_python server name method to use the server object rather
224 than the connection object.
225 * Added a parameter to the ResourceMap.MapResource class to permit automatic
226 redirects into resource hierarchies when no trailing "/" was given in the
227 URL; changed the updated virtual path info so that empty values may be set
228 (the guarantee that "/" will always appear no longer applies).
229 * Fixed virtual path info retrieval when the value is an empty string.
230
231 New in WebStack 0.9 (Changes since WebStack 0.8)
232 ------------------------------------------------
233
234 * Standardised error handling in the adapters so that tracebacks can be
235 suppressed and an internal server error condition raised.
236 * Added overriding of path info in transactions.
237 * Added a ResourceMap resource for dispatching to different resources
238 according to path components.
239 * Standardised deployment for some frameworks (see docs/deploying.html).
240 * Introductory documentation in XHTML format.
241 * Added server name and port methods to the transaction.
242 * Added a simple demonstration application, incorporating many of the
243 examples and launched under a single script.
244 * Fixed mod_python native sessions.
245 * Fixed Zope request stream access.
246 * WebStack is now licensed under the LGPL - see docs/COPYING.txt for
247 details.
248
249 New in WebStack 0.8 (Changes since WebStack 0.7)
250 ------------------------------------------------
251
252 * Added a standard exception, EndOfResponse, which can be used to
253 immediately stop the processing/production of a response; this is useful
254 when resources need to issue a redirect without unnecessary content being
255 generated, for example.
256 * Fixed path information for Zope.
257 * Added WSGI support.
258 * Verified Twisted 1.3.0 support with Python 2.3.3.
259
260 New in WebStack 0.7 (Changes since WebStack 0.6)
261 ------------------------------------------------
262
263 * Fixed path information semantics.
264 * Fixed file upload semantics.
265 * Fixed content type handling for Unicode output and for interpreting
266 request body fields/parameters (although some improvement remains).
267 * Added a method to discover the chosen response stream encoding.
268 * Fixed field/parameter retrieval so that path and body fields are distinct,
269 regardless of the framework employed.
270 * Added a method to get a combination of path and body fields (suggested by
271 Jacob Smullyan).
272 * Introduced Zope 2 support.
273 * Improved Jython/Java Servlet API support (although a special PyServlet
274 class must now be used, and certain libraries must be deployed with
275 applications).
276 * Introduced authentication/authorisation support for Jython/Java Servlet
277 API.
278 * Session support has been added (except for Webware 0.8.1).
279 * Alternative cookie support for mod_python has been added.
280 * Cookie support now supports encoded Unicode sequences for names and
281 values.
282
283 New in WebStack 0.6 (Changes since WebStack 0.5)
284 ------------------------------------------------
285
286 * Introduced Jython/Java Servlet API support.
287 * Minor fixes to example applications and to BaseHTTPRequestHandler.
288
289 New in WebStack 0.5 (Changes since WebStack 0.4)
290 ------------------------------------------------
291
292 * Changed request body fields/parameters so that they are now represented
293 using Unicode objects rather than plain strings.
294 * Introduced better support for Unicode in response streams.
295
296 New in WebStack 0.4 (Changes since WebStack 0.3)
297 ------------------------------------------------
298
299 * Added application definition of user identity, permitting alternative
300 authentication mechanisms.
301 * Improved BaseHTTPRequestHandler and mod_python reliability around fields
302 from request bodies.
303 * Provided stream and environment parameterisation in the CGI adapter.
304 * Added LoginRedirect and Login examples.
305 * Added get_path_without_query and fixed get_path behaviour.
306
307 New in WebStack 0.3 (Changes since WebStack 0.2)
308 ------------------------------------------------
309
310 * Added better header support for Webware (suggested by Ian Bicking).
311 * Introduced CGI and Java Servlet support (the latter is currently
312 broken/unfinished).
313 * Introduced support for cookies.
314
315 Future Work
316 -----------
317
318 (Essential)
319
320 Twisted 1.3.0 does not provide file upload metadata, and Twisted Web 0.5.0
321 also seems to be missing this functionality. It isn't obvious whether Twisted
322 Web2 will just copy its predecessors and provide a similarly limited API.
323 Perhaps the Twisted support needs to resemble the CGI support much more when
324 handling fields.
325
326 JythonServlet libraries need to be configured using sys.add_package when
327 these do not feature in the compiled-in list. Adding such configuration to
328 the handler may be most appropriate (since the web.xml file can be too
329 arcane), but this needs testing.
330
331 The algorithm employed in the WebStack.Helpers.Auth.get_token function
332 should be reviewed and improved for better security.
333
334 (Important)
335
336 Field access needs testing, especially for anything using the
337 cgi.FieldStorage class, and the way file uploads are exposed should be
338 reviewed (currently the meta-data is not exposed). The acquisition of fields
339 from specific sources should be tested with different request methods - some
340 frameworks provide path fields in the body fields dictionary, others (eg.
341 Zope) change the fields exposed depending on request method.
342
343 Interpretation of path field encodings needs to be verified. Currently,
344 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
345 ISO-8859-1, but it might be the case that some such fields might be
346 submitted as UTF-8. The decode_path method on Transaction does do much of the
347 work that is likely to be required, however. Still, a good policy for decoding
348 path fields, reducing the number of times one might specify the encoding in
349 various method calls, may be important.
350
351 An interesting test of encodings is to introduce things like the following to
352 the path info and query string sections of the URL: %25F0?%E6=%F8&%25F0=%F8
353 This should produce the following decoded result: %F0?æ=ø&%F0=ø
354 (The above needs to be read in ISO-8859-1 or ISO-8859-15.)
355
356 Cookie objects need defining strictly, especially since the standard library
357 Cookie object behaves differently to mod_python (and possibly Webware)
358 Cookie objects. Moreover, the set_cookie_value method needs to provide
359 access to the usual cookie parameters as supported by the frameworks. The
360 standard library Cookie module has issues with Unicode cookie names (and
361 possibly values) - this is worked around, but it would be best to resolve
362 this comprehensively.
363
364 UTF-16 (and possibly other encodings) causes problems with HTML form data
365 sent in POST requests using the application/x-www-form-urlencoded content
366 type. This should be reviewed at a later date when proper standardisation
367 has taken place.
368
369 Session support, especially through WebStack.Helpers.Session, should be
370 reviewed and be made compatible with non-cookie mechanisms.
371
372 Locking in the session support and in DirectoryRepository should be improved.
373
374 HeaderValue objects should be employed more extensively. Thus, the header
375 access methods may need to change their behaviour slightly. The get_headers
376 method should potentially return a list for each item in the dictionary.
377
378 WSGI support could demand that a special "end of headers" method be
379 introduced into WebStack, thus making response output more efficient (and
380 probably also for other frameworks, too).
381
382 Investigate proper support for HEAD, OPTIONS and other request methods.
383
384 Consider packages for different operating systems (other than Debian).
385
386 Investigate cStringIO usage.
387
388 The location of deployed applications in the filesystem should be exposed to
389 those applications. (This is actually available in the __file__ module
390 variable.) A resource could be provided to record the "root" path and added to
391 a resource hierarchy or site map. Note that PathSelector records the "root"
392 path, although it is not automatically deployed.
393
394 (Completed/rejected)
395
396 Path information should be consistent across all frameworks, and the "path
397 info" value should be meaningful. (This should now be correct.)
398
399 Investigate the nicer functions in the cgi module, discarding the "magic"
400 stuff like FieldStorage. (These nicer functions are used by projects like
401 Twisted - as of 1.3.0 at least - and do not give the necessary information we
402 require.)
403
404 Release Procedures
405 ------------------
406
407 Update the WebStack/__init__.py __version__ attribute.
408 Change the version number and package filename/directory in the documentation.
409 Change code examples in the documentation if appropriate.
410 Update the release notes (see above).
411 Check the setup.py file and ensure that all package directories are mentioned.
412 Check the release information in the PKG-INFO file and in the package
413 changelog (and other files).
414 Tag, export.
415 Generate the PyServlet classes.
416 Generate the API documentation.
417 Remove generated .pyc files: rm `find . -name "*.pyc"`
418 Archive, upload.
419 Upload the introductory documentation.
420 Update PyPI, PythonInfo Wiki entries.
421
422 Generating the PyServlet Classes
423 --------------------------------
424
425 In order to generate the PyServlet classes, it is necessary to run the
426 supplied script:
427
428 ./tools/JavaServlet/compile.sh
429
430 This produces Java classes and a .jar file for use by WebStack applications
431 running on the Java platform.
432
433 Generating the API Documentation
434 --------------------------------
435
436 In order to prepare the API documentation, it is necessary to generate some
437 Web pages from the Python source code. For this, the epydoc application must
438 be available on your system. Then, inside the distribution directory, run the
439 apidocs.sh tool script as follows:
440
441 ./tools/apidocs.sh
442
443 Some warnings may be generated by the script, but the result should be a new
444 apidocs directory within the distribution directory.
445
446 Making Packages
447 ---------------
448
449 To make Debian-based packages:
450
451 1. Create new package directories under packages if necessary.
452 2. Make a symbolic link in the distribution's root directory to keep the
453 Debian tools happy. For example:
454
455 ln -s packages/ubuntu-hoary/python2.4-webstack/debian/
456 ln -s packages/ubuntu-feisty/python-webstack/debian/
457
458 3. Run the package builder:
459
460 dpkg-buildpackage -rfakeroot
461
462 4. Locate and tidy up the packages in the parent directory of the
463 distribution's root directory.