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