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 * Changed the default_charset on WebStack.Generic.Transaction to UTF-8,
41 introducing a safe_default_charset attribute which employs ISO-8859-1, and
42 removing the default encoding on various resources, making them rely on
43 the default_charset property instead. The EncodingSelector should be used
44 to override this setting if appropriate.
45 * Added a StringResource to WebStack.Resources.Static, serving strings as
46 responses.
47 * Added experimental OpenID support; improved the authentication resources
48 and mechanisms.
49 * Added a StoreSelector to WebStack.Resources.Selectors in order to provide
50 a convenient mechanism for database-related applications.
51
52 New in WebStack 1.2.7 (Changes since WebStack 1.2.6)
53 ----------------------------------------------------
54
55 * Fixed the MessageBodyStream class, adding an optional parameter to the
56 readline method which seems to be necessary when handling multipart
57 requests.
58 * Introduced stream usage for file uploads where possible, in order to
59 reduce memory usage (suggested by Kevin Glynn), adding a stream attribute
60 to the FileContent class and making the content attribute a property.
61 * Removed error handling in the examples in order to make troubleshooting
62 easier.
63 * Fixed header issues by introducing a special HeaderDict class which
64 enforces the case-insensitivity expected of header dictionaries.
65
66 New in WebStack 1.2.6 (Changes since WebStack 1.2.5)
67 ----------------------------------------------------
68
69 * Added a jython-webstack package for Ubuntu Feisty (7.04).
70 * Improved support for Jython on Ubuntu Feisty (7.04), adding python.path
71 and python.cachedir settings which respectively avoid issues with missing
72 libraries (due to the separation of libraries in the Ubuntu package) and
73 with failed imports (due to a read-only class cache directory).
74 * Improved the webstack_java_build.py script and added a deployment
75 descriptor for JSP to accompany the new Java Servlet-specific JSPTest
76 example.
77 * Added a special Java Servlet-specific get_servlet method to support the
78 JSPTest example. It is envisaged that a more general method could be made
79 available for all frameworks in order to support access to underlying
80 request dispatchers and other framework facilities.
81 * Added more Jython-related documentation as suggested by Kevin Glynn.
82 * Added missing request headers for CGI/WSGI environment variables.
83 * Fixed Webware support to work with Webware 0.9.4.
84 * Fixed/improved Zope path value retrieval.
85 * Added support for wsgiref, changing the WSGI deploy function for CGI-based
86 applications to deploy_as_cgi and adding a deploy_with_wsgiref function.
87
88 New in WebStack 1.2.5 (Changes since WebStack 1.2.4)
89 ----------------------------------------------------
90
91 * Fixed mod_python status codes using a solution proposed by John Krukoff.
92 * Fixed a Twisted deprecation warning when accessing port numbers, thanks to
93 John Krukoff.
94 * Added Ubuntu Feisty (7.04) package support.
95 * Tidied up the documentation HTML.
96
97 New in WebStack 1.2.4 (Changes since WebStack 1.2.3)
98 ----------------------------------------------------
99
100 * Made a SessionDirectoryRepository which uses directories for data produced
101 by the shelve module, rather than attempting to manipulate files produced
102 by the shelve module, since the details of such files may differ between
103 environments: a situation noticed by John Krukoff in an environment
104 without the bsddb module installed.
105
106 New in WebStack 1.2.3 (Changes since WebStack 1.2.2)
107 ----------------------------------------------------
108
109 * Fixed inadvertent OpenSSL dependency, noticed by John Krukoff.
110
111 New in WebStack 1.2.2 (Changes since WebStack 1.2.1)
112 ----------------------------------------------------
113
114 * Added an EncodingSelector class for the setting of default encodings on
115 transactions.
116 * Added some documentation about path processing strategies.
117 * Added a secure variant of the BaseHTTPServer provided in the adapter for
118 BaseHTTPRequestHandler.
119
120 New in WebStack 1.2.1 (Changes since WebStack 1.2)
121 --------------------------------------------------
122
123 * Fixed mod_python get_content_type method.
124 * Fixed LoginResource form field processing; changed the field type to
125 password.
126 * Exposed LoginResource and LoginRedirectResource page contents as
127 attributes.
128 * Added documentation about extending LoginRedirectResource and using
129 PathSelector to remember an application's root path.
130 * Changed handle_errors to 1 throughout the examples.
131
132 New in WebStack 1.2 (Changes since WebStack 1.1.2)
133 --------------------------------------------------
134
135 * Added support for Django.
136 * Fixed documentation about the representation of file upload fields.
137 * Changed mod_python, Java Servlet and Webware (> 0.8.1) deployment to use a
138 deploy function instead of more complicated configuration mechanisms.
139 * Improved mod_python deployment documentation and tools so that cleaner
140 application paths/URLs can now be used.
141 * Moved user and path_info default definitions into WebStack.Generic as
142 class attributes.
143 * Fixed encoding usage issues with path fields when using get_fields in a
144 Zope environment.
145 * Added a FileResource class to WebStack.Resources.Static.
146 * Made DirectoryRepository convert filenames to Unicode in all cases.
147 * Renamed the Apache and Java Servlet tools, making them scripts which are
148 installed by setup.py.
149 * Fixed CGI content charsets and languages support.
150 * Fixed CGI cookie output.
151 * Added URL overriding in the LoginRedirectResource.
152 * Exposed a get_target function from WebStack.Resources.Login in order to
153 better support alternative login resources.
154 * Added improved error reporting for BaseHTTPRequestHandler, CGI, Django and
155 WSGI.
156 * Added a traverse_path method to the Transaction class.
157 * Made a path_encoding alias for urlencoding in the initialisation of
158 WebStack.Resources.ResourceMap objects.
159 * Added a Selectors module to WebStack.Resources in order to support common
160 resource selection patterns.
161
162 New in WebStack 1.1.2 (Changes since WebStack 1.1.1)
163 ----------------------------------------------------
164
165 * Fixed missing import in WebStack.Repositories.Directory.
166
167 New in WebStack 1.1.1 (Changes since WebStack 1.1)
168 --------------------------------------------------
169
170 * Fixed update_path to handle the root path properly.
171
172 New in WebStack 1.1 (Changes since WebStack 1.0)
173 ------------------------------------------------
174
175 * Added a Repositories package to provide session-like support for
176 different kinds of storage.
177 * Added an explicit filesystem encoding to the Calendar example and adopted
178 the DirectoryRepository from the Repositories package.
179 * Added get_path_without_info, update_path and redirect methods to the
180 Transaction class.
181 * Added get_attributes (attribute support) to the Transaction class.
182 * Added a values method to Helpers.Session.Wrapper.
183 * Fixed get_processed_virtual_path_info (to match from right to left).
184 * Improved/fixed exception handling in the adapters so that transactions are
185 committed as the final act of an adapter experiencing an unhandled
186 exception. This should result in session stores being closed properly.
187 * Changed the Helpers.Session.SessionStore to use DirectoryRepository.
188 * Made the "not found" behaviour of DirectoryResource more configurable.
189 * Added documentation for MapResource and DirectoryResource.
190 * Fixed the distribution names in the Ubuntu changelog.
191
192 New in WebStack 1.0 (Changes since WebStack 0.10)
193 -------------------------------------------------
194
195 * Changed the behaviour of get_path, get_path_without_query, get_path_info,
196 get_virtual_path_info, get_processed_virtual_path_info and
197 get_fields_from_path to return Unicode data decoded using the optional
198 encoding parameter or a common default encoding.
199 * Fixed file upload values so that FileContent objects are returned for such
200 fields in get_fields_from_body and get_fields.
201 (Warning! Except for Twisted!)
202 * Fixed the JavaServlet support so that streams and file content are
203 obtained as "almost" plain strings.
204 * Updated/fixed LoginResource and LoginRedirectResource to use the updated
205 path API and to handle special characters properly.
206 * Added convenience methods to Transaction for the decoding and encoding of
207 path values (to and from Unicode objects) - see the decode_path and
208 encode_path methods.
209 * Added the notion of processed virtual path info - the part of the original
210 path info not represented in the current virtual path info.
211 * Added "pass through" behaviour to ResourceMap.MapResource (prompted by a
212 patch from Scott Robinson).
213 * Fixed ResourceMap.MapResource to handle non-existent resources properly
214 (where the virtual path info is only one component in length).
215 * Added Debian package support.
216 * Added automatic session directory creation for the WebStack sessions
217 implementation.
218 * Added support for the repeated retrieval of sessions from the same
219 WebStack session store, avoiding deadlocks.
220 * Fixed the calendar example, making it perform a proper function.
221 * Made the BaseHTTPRequestHandler and Twisted SimpleWithLogin applications
222 include the Login application, since Konqueror (at least) does not share
223 cookies across different port numbers on the same host.
224 * Added the SimpleWithLogin and Login applications to the demonstration.
225 * Improved the documentation, adding information on request headers, and
226 describing file upload and session support limitations.
227 * Improved the AOLserver-related notes for CGI and Webware, adding a patch
228 for Webware in order to work around AOLserver issues.
229
230 New in WebStack 0.10 (Changes since WebStack 0.9)
231 -------------------------------------------------
232
233 * Changes to make the tools/demo.py script work on Windows (and other)
234 platforms (suggested by Jim Madsen).
235 * Fixed end of header newlines for CGI (suggested by Matt Harrison).
236 * Minor documentation fixes and improvements, adding information on
237 AOLserver in the CGI and Webware notes.
238 * Changed the mod_python server name method to use the server object rather
239 than the connection object.
240 * Added a parameter to the ResourceMap.MapResource class to permit automatic
241 redirects into resource hierarchies when no trailing "/" was given in the
242 URL; changed the updated virtual path info so that empty values may be set
243 (the guarantee that "/" will always appear no longer applies).
244 * Fixed virtual path info retrieval when the value is an empty string.
245
246 New in WebStack 0.9 (Changes since WebStack 0.8)
247 ------------------------------------------------
248
249 * Standardised error handling in the adapters so that tracebacks can be
250 suppressed and an internal server error condition raised.
251 * Added overriding of path info in transactions.
252 * Added a ResourceMap resource for dispatching to different resources
253 according to path components.
254 * Standardised deployment for some frameworks (see docs/deploying.html).
255 * Introductory documentation in XHTML format.
256 * Added server name and port methods to the transaction.
257 * Added a simple demonstration application, incorporating many of the
258 examples and launched under a single script.
259 * Fixed mod_python native sessions.
260 * Fixed Zope request stream access.
261 * WebStack is now licensed under the LGPL - see docs/COPYING.txt for
262 details.
263
264 New in WebStack 0.8 (Changes since WebStack 0.7)
265 ------------------------------------------------
266
267 * Added a standard exception, EndOfResponse, which can be used to
268 immediately stop the processing/production of a response; this is useful
269 when resources need to issue a redirect without unnecessary content being
270 generated, for example.
271 * Fixed path information for Zope.
272 * Added WSGI support.
273 * Verified Twisted 1.3.0 support with Python 2.3.3.
274
275 New in WebStack 0.7 (Changes since WebStack 0.6)
276 ------------------------------------------------
277
278 * Fixed path information semantics.
279 * Fixed file upload semantics.
280 * Fixed content type handling for Unicode output and for interpreting
281 request body fields/parameters (although some improvement remains).
282 * Added a method to discover the chosen response stream encoding.
283 * Fixed field/parameter retrieval so that path and body fields are distinct,
284 regardless of the framework employed.
285 * Added a method to get a combination of path and body fields (suggested by
286 Jacob Smullyan).
287 * Introduced Zope 2 support.
288 * Improved Jython/Java Servlet API support (although a special PyServlet
289 class must now be used, and certain libraries must be deployed with
290 applications).
291 * Introduced authentication/authorisation support for Jython/Java Servlet
292 API.
293 * Session support has been added (except for Webware 0.8.1).
294 * Alternative cookie support for mod_python has been added.
295 * Cookie support now supports encoded Unicode sequences for names and
296 values.
297
298 New in WebStack 0.6 (Changes since WebStack 0.5)
299 ------------------------------------------------
300
301 * Introduced Jython/Java Servlet API support.
302 * Minor fixes to example applications and to BaseHTTPRequestHandler.
303
304 New in WebStack 0.5 (Changes since WebStack 0.4)
305 ------------------------------------------------
306
307 * Changed request body fields/parameters so that they are now represented
308 using Unicode objects rather than plain strings.
309 * Introduced better support for Unicode in response streams.
310
311 New in WebStack 0.4 (Changes since WebStack 0.3)
312 ------------------------------------------------
313
314 * Added application definition of user identity, permitting alternative
315 authentication mechanisms.
316 * Improved BaseHTTPRequestHandler and mod_python reliability around fields
317 from request bodies.
318 * Provided stream and environment parameterisation in the CGI adapter.
319 * Added LoginRedirect and Login examples.
320 * Added get_path_without_query and fixed get_path behaviour.
321
322 New in WebStack 0.3 (Changes since WebStack 0.2)
323 ------------------------------------------------
324
325 * Added better header support for Webware (suggested by Ian Bicking).
326 * Introduced CGI and Java Servlet support (the latter is currently
327 broken/unfinished).
328 * Introduced support for cookies.
329
330 Future Work
331 -----------
332
333 (Essential)
334
335 Twisted 1.3.0 does not provide file upload metadata, and Twisted Web 0.5.0
336 also seems to be missing this functionality. It isn't obvious whether Twisted
337 Web2 will just copy its predecessors and provide a similarly limited API.
338 Perhaps the Twisted support needs to resemble the CGI support much more when
339 handling fields.
340
341 JythonServlet libraries need to be configured using sys.add_package when
342 these do not feature in the compiled-in list. Adding such configuration to
343 the handler may be most appropriate (since the web.xml file can be too
344 arcane), but this needs testing.
345
346 The algorithm employed in the WebStack.Helpers.Auth.get_token function
347 should be reviewed and improved for better security.
348
349 (Important)
350
351 Field access needs testing, especially for anything using the
352 cgi.FieldStorage class, and the way file uploads are exposed should be
353 reviewed (currently the meta-data is not exposed). The acquisition of fields
354 from specific sources should be tested with different request methods - some
355 frameworks provide path fields in the body fields dictionary, others (eg.
356 Zope) change the fields exposed depending on request method.
357
358 Interpretation of path field encodings needs to be verified. Currently,
359 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
360 ISO-8859-1, but it might be the case that some such fields might be
361 submitted as UTF-8. The decode_path method on Transaction does do much of the
362 work that is likely to be required, however. Still, a good policy for decoding
363 path fields, reducing the number of times one might specify the encoding in
364 various method calls, may be important.
365
366 An interesting test of encodings is to introduce things like the following to
367 the path info and query string sections of the URL: %25F0?%E6=%F8&%25F0=%F8
368 This should produce the following decoded result: %F0?æ=ø&%F0=ø
369 (The above needs to be read in ISO-8859-1 or ISO-8859-15.)
370
371 Cookie objects need defining strictly, especially since the standard library
372 Cookie object behaves differently to mod_python (and possibly Webware)
373 Cookie objects. Moreover, the set_cookie_value method needs to provide
374 access to the usual cookie parameters as supported by the frameworks. The
375 standard library Cookie module has issues with Unicode cookie names (and
376 possibly values) - this is worked around, but it would be best to resolve
377 this comprehensively.
378
379 UTF-16 (and possibly other encodings) causes problems with HTML form data
380 sent in POST requests using the application/x-www-form-urlencoded content
381 type. This should be reviewed at a later date when proper standardisation
382 has taken place.
383
384 Session support, especially through WebStack.Helpers.Session, should be
385 reviewed and be made compatible with non-cookie mechanisms.
386
387 Locking in the session support and in DirectoryRepository should be improved.
388
389 HeaderValue objects should be employed more extensively. Thus, the header
390 access methods may need to change their behaviour slightly. The get_headers
391 method should potentially return a list for each item in the dictionary.
392
393 WSGI support could demand that a special "end of headers" method be
394 introduced into WebStack, thus making response output more efficient (and
395 probably also for other frameworks, too).
396
397 Investigate proper support for HEAD, OPTIONS and other request methods.
398
399 Consider packages for different operating systems (other than Debian).
400
401 Investigate cStringIO usage.
402
403 The location of deployed applications in the filesystem should be exposed to
404 those applications. (This is actually available in the __file__ module
405 variable.) A resource could be provided to record the "root" path and added to
406 a resource hierarchy or site map. Note that PathSelector records the "root"
407 path, although it is not automatically deployed.
408
409 (Completed/rejected)
410
411 Path information should be consistent across all frameworks, and the "path
412 info" value should be meaningful. (This should now be correct.)
413
414 Investigate the nicer functions in the cgi module, discarding the "magic"
415 stuff like FieldStorage. (These nicer functions are used by projects like
416 Twisted - as of 1.3.0 at least - and do not give the necessary information we
417 require.)
418
419 Release Procedures
420 ------------------
421
422 Update the WebStack/__init__.py __version__ attribute.
423 Change the version number and package filename/directory in the documentation.
424 Change code examples in the documentation if appropriate.
425 Update the release notes (see above).
426 Check the setup.py file and ensure that all package directories are mentioned.
427 Check the release information in the PKG-INFO file and in the package
428 changelog (and other files).
429 Tag, export.
430 Generate the PyServlet classes.
431 Generate the API documentation.
432 Remove generated .pyc files: rm `find . -name "*.pyc"`
433 Archive, upload.
434 Upload the introductory documentation.
435 Update PyPI, PythonInfo Wiki entries.
436
437 Generating the PyServlet Classes
438 --------------------------------
439
440 In order to generate the PyServlet classes, it is necessary to run the
441 supplied script:
442
443 ./tools/JavaServlet/compile.sh
444
445 This produces Java classes and a .jar file for use by WebStack applications
446 running on the Java platform.
447
448 Generating the API Documentation
449 --------------------------------
450
451 In order to prepare the API documentation, it is necessary to generate some
452 Web pages from the Python source code. For this, the epydoc application must
453 be available on your system. Then, inside the distribution directory, run the
454 apidocs.sh tool script as follows:
455
456 ./tools/apidocs.sh
457
458 Some warnings may be generated by the script, but the result should be a new
459 apidocs directory within the distribution directory.
460
461 Making Packages
462 ---------------
463
464 To make Debian-based packages:
465
466 1. Create new package directories under packages if necessary.
467 2. Make a symbolic link in the distribution's root directory to keep the
468 Debian tools happy. For example, one of the following:
469
470 ln -s packages/ubuntu-hoary/python2.4-webstack/debian/
471 ln -s packages/ubuntu-feisty/python-webstack/debian/
472 ln -s packages/ubuntu-feisty/jython-webstack/debian/
473
474 3. Run the package builder:
475
476 dpkg-buildpackage -rfakeroot
477
478 4. Locate and tidy up the packages in the parent directory of the
479 distribution's root directory.