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 1.3 (Changes since WebStack 1.2.7)
38 --------------------------------------------------
39
40 * Added a StringResource to WebStack.Resources.Static, serving strings as
41 responses.
42 * Added experimental OpenID support; improved the authentication resources
43 and mechanisms.
44
45 New in WebStack 1.2.7 (Changes since WebStack 1.2.6)
46 ----------------------------------------------------
47
48 * Fixed the MessageBodyStream class, adding an optional parameter to the
49 readline method which seems to be necessary when handling multipart
50 requests.
51 * Introduced stream usage for file uploads where possible, in order to
52 reduce memory usage (suggested by Kevin Glynn), adding a stream attribute
53 to the FileContent class and making the content attribute a property.
54 * Removed error handling in the examples in order to make troubleshooting
55 easier.
56 * Fixed header issues by introducing a special HeaderDict class which
57 enforces the case-insensitivity expected of header dictionaries.
58
59 New in WebStack 1.2.6 (Changes since WebStack 1.2.5)
60 ----------------------------------------------------
61
62 * Added a jython-webstack package for Ubuntu Feisty (7.04).
63 * Improved support for Jython on Ubuntu Feisty (7.04), adding python.path
64 and python.cachedir settings which respectively avoid issues with missing
65 libraries (due to the separation of libraries in the Ubuntu package) and
66 with failed imports (due to a read-only class cache directory).
67 * Improved the webstack_java_build.py script and added a deployment
68 descriptor for JSP to accompany the new Java Servlet-specific JSPTest
69 example.
70 * Added a special Java Servlet-specific get_servlet method to support the
71 JSPTest example. It is envisaged that a more general method could be made
72 available for all frameworks in order to support access to underlying
73 request dispatchers and other framework facilities.
74 * Added more Jython-related documentation as suggested by Kevin Glynn.
75 * Added missing request headers for CGI/WSGI environment variables.
76 * Fixed Webware support to work with Webware 0.9.4.
77 * Fixed/improved Zope path value retrieval.
78 * Added support for wsgiref, changing the WSGI deploy function for CGI-based
79 applications to deploy_as_cgi and adding a deploy_with_wsgiref function.
80
81 New in WebStack 1.2.5 (Changes since WebStack 1.2.4)
82 ----------------------------------------------------
83
84 * Fixed mod_python status codes using a solution proposed by John Krukoff.
85 * Fixed a Twisted deprecation warning when accessing port numbers, thanks to
86 John Krukoff.
87 * Added Ubuntu Feisty (7.04) package support.
88 * Tidied up the documentation HTML.
89
90 New in WebStack 1.2.4 (Changes since WebStack 1.2.3)
91 ----------------------------------------------------
92
93 * Made a SessionDirectoryRepository which uses directories for data produced
94 by the shelve module, rather than attempting to manipulate files produced
95 by the shelve module, since the details of such files may differ between
96 environments: a situation noticed by John Krukoff in an environment
97 without the bsddb module installed.
98
99 New in WebStack 1.2.3 (Changes since WebStack 1.2.2)
100 ----------------------------------------------------
101
102 * Fixed inadvertent OpenSSL dependency, noticed by John Krukoff.
103
104 New in WebStack 1.2.2 (Changes since WebStack 1.2.1)
105 ----------------------------------------------------
106
107 * Added an EncodingSelector class for the setting of default encodings on
108 transactions.
109 * Added some documentation about path processing strategies.
110 * Added a secure variant of the BaseHTTPServer provided in the adapter for
111 BaseHTTPRequestHandler.
112
113 New in WebStack 1.2.1 (Changes since WebStack 1.2)
114 --------------------------------------------------
115
116 * Fixed mod_python get_content_type method.
117 * Fixed LoginResource form field processing; changed the field type to
118 password.
119 * Exposed LoginResource and LoginRedirectResource page contents as
120 attributes.
121 * Added documentation about extending LoginRedirectResource and using
122 PathSelector to remember an application's root path.
123 * Changed handle_errors to 1 throughout the examples.
124
125 New in WebStack 1.2 (Changes since WebStack 1.1.2)
126 --------------------------------------------------
127
128 * Added support for Django.
129 * Fixed documentation about the representation of file upload fields.
130 * Changed mod_python, Java Servlet and Webware (> 0.8.1) deployment to use a
131 deploy function instead of more complicated configuration mechanisms.
132 * Improved mod_python deployment documentation and tools so that cleaner
133 application paths/URLs can now be used.
134 * Moved user and path_info default definitions into WebStack.Generic as
135 class attributes.
136 * Fixed encoding usage issues with path fields when using get_fields in a
137 Zope environment.
138 * Added a FileResource class to WebStack.Resources.Static.
139 * Made DirectoryRepository convert filenames to Unicode in all cases.
140 * Renamed the Apache and Java Servlet tools, making them scripts which are
141 installed by setup.py.
142 * Fixed CGI content charsets and languages support.
143 * Fixed CGI cookie output.
144 * Added URL overriding in the LoginRedirectResource.
145 * Exposed a get_target function from WebStack.Resources.Login in order to
146 better support alternative login resources.
147 * Added improved error reporting for BaseHTTPRequestHandler, CGI, Django and
148 WSGI.
149 * Added a traverse_path method to the Transaction class.
150 * Made a path_encoding alias for urlencoding in the initialisation of
151 WebStack.Resources.ResourceMap objects.
152 * Added a Selectors module to WebStack.Resources in order to support common
153 resource selection patterns.
154
155 New in WebStack 1.1.2 (Changes since WebStack 1.1.1)
156 ----------------------------------------------------
157
158 * Fixed missing import in WebStack.Repositories.Directory.
159
160 New in WebStack 1.1.1 (Changes since WebStack 1.1)
161 --------------------------------------------------
162
163 * Fixed update_path to handle the root path properly.
164
165 New in WebStack 1.1 (Changes since WebStack 1.0)
166 ------------------------------------------------
167
168 * Added a Repositories package to provide session-like support for
169 different kinds of storage.
170 * Added an explicit filesystem encoding to the Calendar example and adopted
171 the DirectoryRepository from the Repositories package.
172 * Added get_path_without_info, update_path and redirect methods to the
173 Transaction class.
174 * Added get_attributes (attribute support) to the Transaction class.
175 * Added a values method to Helpers.Session.Wrapper.
176 * Fixed get_processed_virtual_path_info (to match from right to left).
177 * Improved/fixed exception handling in the adapters so that transactions are
178 committed as the final act of an adapter experiencing an unhandled
179 exception. This should result in session stores being closed properly.
180 * Changed the Helpers.Session.SessionStore to use DirectoryRepository.
181 * Made the "not found" behaviour of DirectoryResource more configurable.
182 * Added documentation for MapResource and DirectoryResource.
183 * Fixed the distribution names in the Ubuntu changelog.
184
185 New in WebStack 1.0 (Changes since WebStack 0.10)
186 -------------------------------------------------
187
188 * Changed the behaviour of get_path, get_path_without_query, get_path_info,
189 get_virtual_path_info, get_processed_virtual_path_info and
190 get_fields_from_path to return Unicode data decoded using the optional
191 encoding parameter or a common default encoding.
192 * Fixed file upload values so that FileContent objects are returned for such
193 fields in get_fields_from_body and get_fields.
194 (Warning! Except for Twisted!)
195 * Fixed the JavaServlet support so that streams and file content are
196 obtained as "almost" plain strings.
197 * Updated/fixed LoginResource and LoginRedirectResource to use the updated
198 path API and to handle special characters properly.
199 * Added convenience methods to Transaction for the decoding and encoding of
200 path values (to and from Unicode objects) - see the decode_path and
201 encode_path methods.
202 * Added the notion of processed virtual path info - the part of the original
203 path info not represented in the current virtual path info.
204 * Added "pass through" behaviour to ResourceMap.MapResource (prompted by a
205 patch from Scott Robinson).
206 * Fixed ResourceMap.MapResource to handle non-existent resources properly
207 (where the virtual path info is only one component in length).
208 * Added Debian package support.
209 * Added automatic session directory creation for the WebStack sessions
210 implementation.
211 * Added support for the repeated retrieval of sessions from the same
212 WebStack session store, avoiding deadlocks.
213 * Fixed the calendar example, making it perform a proper function.
214 * Made the BaseHTTPRequestHandler and Twisted SimpleWithLogin applications
215 include the Login application, since Konqueror (at least) does not share
216 cookies across different port numbers on the same host.
217 * Added the SimpleWithLogin and Login applications to the demonstration.
218 * Improved the documentation, adding information on request headers, and
219 describing file upload and session support limitations.
220 * Improved the AOLserver-related notes for CGI and Webware, adding a patch
221 for Webware in order to work around AOLserver issues.
222
223 New in WebStack 0.10 (Changes since WebStack 0.9)
224 -------------------------------------------------
225
226 * Changes to make the tools/demo.py script work on Windows (and other)
227 platforms (suggested by Jim Madsen).
228 * Fixed end of header newlines for CGI (suggested by Matt Harrison).
229 * Minor documentation fixes and improvements, adding information on
230 AOLserver in the CGI and Webware notes.
231 * Changed the mod_python server name method to use the server object rather
232 than the connection object.
233 * Added a parameter to the ResourceMap.MapResource class to permit automatic
234 redirects into resource hierarchies when no trailing "/" was given in the
235 URL; changed the updated virtual path info so that empty values may be set
236 (the guarantee that "/" will always appear no longer applies).
237 * Fixed virtual path info retrieval when the value is an empty string.
238
239 New in WebStack 0.9 (Changes since WebStack 0.8)
240 ------------------------------------------------
241
242 * Standardised error handling in the adapters so that tracebacks can be
243 suppressed and an internal server error condition raised.
244 * Added overriding of path info in transactions.
245 * Added a ResourceMap resource for dispatching to different resources
246 according to path components.
247 * Standardised deployment for some frameworks (see docs/deploying.html).
248 * Introductory documentation in XHTML format.
249 * Added server name and port methods to the transaction.
250 * Added a simple demonstration application, incorporating many of the
251 examples and launched under a single script.
252 * Fixed mod_python native sessions.
253 * Fixed Zope request stream access.
254 * WebStack is now licensed under the LGPL - see docs/COPYING.txt for
255 details.
256
257 New in WebStack 0.8 (Changes since WebStack 0.7)
258 ------------------------------------------------
259
260 * Added a standard exception, EndOfResponse, which can be used to
261 immediately stop the processing/production of a response; this is useful
262 when resources need to issue a redirect without unnecessary content being
263 generated, for example.
264 * Fixed path information for Zope.
265 * Added WSGI support.
266 * Verified Twisted 1.3.0 support with Python 2.3.3.
267
268 New in WebStack 0.7 (Changes since WebStack 0.6)
269 ------------------------------------------------
270
271 * Fixed path information semantics.
272 * Fixed file upload semantics.
273 * Fixed content type handling for Unicode output and for interpreting
274 request body fields/parameters (although some improvement remains).
275 * Added a method to discover the chosen response stream encoding.
276 * Fixed field/parameter retrieval so that path and body fields are distinct,
277 regardless of the framework employed.
278 * Added a method to get a combination of path and body fields (suggested by
279 Jacob Smullyan).
280 * Introduced Zope 2 support.
281 * Improved Jython/Java Servlet API support (although a special PyServlet
282 class must now be used, and certain libraries must be deployed with
283 applications).
284 * Introduced authentication/authorisation support for Jython/Java Servlet
285 API.
286 * Session support has been added (except for Webware 0.8.1).
287 * Alternative cookie support for mod_python has been added.
288 * Cookie support now supports encoded Unicode sequences for names and
289 values.
290
291 New in WebStack 0.6 (Changes since WebStack 0.5)
292 ------------------------------------------------
293
294 * Introduced Jython/Java Servlet API support.
295 * Minor fixes to example applications and to BaseHTTPRequestHandler.
296
297 New in WebStack 0.5 (Changes since WebStack 0.4)
298 ------------------------------------------------
299
300 * Changed request body fields/parameters so that they are now represented
301 using Unicode objects rather than plain strings.
302 * Introduced better support for Unicode in response streams.
303
304 New in WebStack 0.4 (Changes since WebStack 0.3)
305 ------------------------------------------------
306
307 * Added application definition of user identity, permitting alternative
308 authentication mechanisms.
309 * Improved BaseHTTPRequestHandler and mod_python reliability around fields
310 from request bodies.
311 * Provided stream and environment parameterisation in the CGI adapter.
312 * Added LoginRedirect and Login examples.
313 * Added get_path_without_query and fixed get_path behaviour.
314
315 New in WebStack 0.3 (Changes since WebStack 0.2)
316 ------------------------------------------------
317
318 * Added better header support for Webware (suggested by Ian Bicking).
319 * Introduced CGI and Java Servlet support (the latter is currently
320 broken/unfinished).
321 * Introduced support for cookies.
322
323 Future Work
324 -----------
325
326 (Essential)
327
328 Twisted 1.3.0 does not provide file upload metadata, and Twisted Web 0.5.0
329 also seems to be missing this functionality. It isn't obvious whether Twisted
330 Web2 will just copy its predecessors and provide a similarly limited API.
331 Perhaps the Twisted support needs to resemble the CGI support much more when
332 handling fields.
333
334 JythonServlet libraries need to be configured using sys.add_package when
335 these do not feature in the compiled-in list. Adding such configuration to
336 the handler may be most appropriate (since the web.xml file can be too
337 arcane), but this needs testing.
338
339 The algorithm employed in the WebStack.Helpers.Auth.get_token function
340 should be reviewed and improved for better security.
341
342 (Important)
343
344 Field access needs testing, especially for anything using the
345 cgi.FieldStorage class, and the way file uploads are exposed should be
346 reviewed (currently the meta-data is not exposed). The acquisition of fields
347 from specific sources should be tested with different request methods - some
348 frameworks provide path fields in the body fields dictionary, others (eg.
349 Zope) change the fields exposed depending on request method.
350
351 Interpretation of path field encodings needs to be verified. Currently,
352 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
353 ISO-8859-1, but it might be the case that some such fields might be
354 submitted as UTF-8. The decode_path method on Transaction does do much of the
355 work that is likely to be required, however. Still, a good policy for decoding
356 path fields, reducing the number of times one might specify the encoding in
357 various method calls, may be important.
358
359 An interesting test of encodings is to introduce things like the following to
360 the path info and query string sections of the URL: %25F0?%E6=%F8&%25F0=%F8
361 This should produce the following decoded result: %F0?æ=ø&%F0=ø
362 (The above needs to be read in ISO-8859-1 or ISO-8859-15.)
363
364 Cookie objects need defining strictly, especially since the standard library
365 Cookie object behaves differently to mod_python (and possibly Webware)
366 Cookie objects. Moreover, the set_cookie_value method needs to provide
367 access to the usual cookie parameters as supported by the frameworks. The
368 standard library Cookie module has issues with Unicode cookie names (and
369 possibly values) - this is worked around, but it would be best to resolve
370 this comprehensively.
371
372 UTF-16 (and possibly other encodings) causes problems with HTML form data
373 sent in POST requests using the application/x-www-form-urlencoded content
374 type. This should be reviewed at a later date when proper standardisation
375 has taken place.
376
377 Session support, especially through WebStack.Helpers.Session, should be
378 reviewed and be made compatible with non-cookie mechanisms.
379
380 Locking in the session support and in DirectoryRepository should be improved.
381
382 HeaderValue objects should be employed more extensively. Thus, the header
383 access methods may need to change their behaviour slightly. The get_headers
384 method should potentially return a list for each item in the dictionary.
385
386 WSGI support could demand that a special "end of headers" method be
387 introduced into WebStack, thus making response output more efficient (and
388 probably also for other frameworks, too).
389
390 Investigate proper support for HEAD, OPTIONS and other request methods.
391
392 Consider packages for different operating systems (other than Debian).
393
394 Investigate cStringIO usage.
395
396 The location of deployed applications in the filesystem should be exposed to
397 those applications. (This is actually available in the __file__ module
398 variable.) A resource could be provided to record the "root" path and added to
399 a resource hierarchy or site map. Note that PathSelector records the "root"
400 path, although it is not automatically deployed.
401
402 (Completed/rejected)
403
404 Path information should be consistent across all frameworks, and the "path
405 info" value should be meaningful. (This should now be correct.)
406
407 Investigate the nicer functions in the cgi module, discarding the "magic"
408 stuff like FieldStorage. (These nicer functions are used by projects like
409 Twisted - as of 1.3.0 at least - and do not give the necessary information we
410 require.)
411
412 Release Procedures
413 ------------------
414
415 Update the WebStack/__init__.py __version__ attribute.
416 Change the version number and package filename/directory in the documentation.
417 Change code examples in the documentation if appropriate.
418 Update the release notes (see above).
419 Check the setup.py file and ensure that all package directories are mentioned.
420 Check the release information in the PKG-INFO file and in the package
421 changelog (and other files).
422 Tag, export.
423 Generate the PyServlet classes.
424 Generate the API documentation.
425 Remove generated .pyc files: rm `find . -name "*.pyc"`
426 Archive, upload.
427 Upload the introductory documentation.
428 Update PyPI, PythonInfo Wiki entries.
429
430 Generating the PyServlet Classes
431 --------------------------------
432
433 In order to generate the PyServlet classes, it is necessary to run the
434 supplied script:
435
436 ./tools/JavaServlet/compile.sh
437
438 This produces Java classes and a .jar file for use by WebStack applications
439 running on the Java platform.
440
441 Generating the API Documentation
442 --------------------------------
443
444 In order to prepare the API documentation, it is necessary to generate some
445 Web pages from the Python source code. For this, the epydoc application must
446 be available on your system. Then, inside the distribution directory, run the
447 apidocs.sh tool script as follows:
448
449 ./tools/apidocs.sh
450
451 Some warnings may be generated by the script, but the result should be a new
452 apidocs directory within the distribution directory.
453
454 Making Packages
455 ---------------
456
457 To make Debian-based packages:
458
459 1. Create new package directories under packages if necessary.
460 2. Make a symbolic link in the distribution's root directory to keep the
461 Debian tools happy. For example, one of the following:
462
463 ln -s packages/ubuntu-hoary/python2.4-webstack/debian/
464 ln -s packages/ubuntu-feisty/python-webstack/debian/
465 ln -s packages/ubuntu-feisty/jython-webstack/debian/
466
467 3. Run the package builder:
468
469 dpkg-buildpackage -rfakeroot
470
471 4. Locate and tidy up the packages in the parent directory of the
472 distribution's root directory.