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.
44 WARNING: These changes could upset some applications. The EncodingSelector
45 should be used to override the default_charset setting if appropriate.
46 * Added an encode_url_without_query to Transaction for use with combined
47 protocol, address and path values.
48 * Added a StringResource to WebStack.Resources.Static, serving strings as
49 responses.
50 * Added experimental OpenID support; improved the authentication resources
51 and mechanisms.
52 * Added a StoreSelector to WebStack.Resources.Selectors in order to provide
53 a convenient mechanism for database-related applications.
54
55 New in WebStack 1.2.7 (Changes since WebStack 1.2.6)
56 ----------------------------------------------------
57
58 * Fixed the MessageBodyStream class, adding an optional parameter to the
59 readline method which seems to be necessary when handling multipart
60 requests.
61 * Introduced stream usage for file uploads where possible, in order to
62 reduce memory usage (suggested by Kevin Glynn), adding a stream attribute
63 to the FileContent class and making the content attribute a property.
64 * Removed error handling in the examples in order to make troubleshooting
65 easier.
66 * Fixed header issues by introducing a special HeaderDict class which
67 enforces the case-insensitivity expected of header dictionaries.
68
69 New in WebStack 1.2.6 (Changes since WebStack 1.2.5)
70 ----------------------------------------------------
71
72 * Added a jython-webstack package for Ubuntu Feisty (7.04).
73 * Improved support for Jython on Ubuntu Feisty (7.04), adding python.path
74 and python.cachedir settings which respectively avoid issues with missing
75 libraries (due to the separation of libraries in the Ubuntu package) and
76 with failed imports (due to a read-only class cache directory).
77 * Improved the webstack_java_build.py script and added a deployment
78 descriptor for JSP to accompany the new Java Servlet-specific JSPTest
79 example.
80 * Added a special Java Servlet-specific get_servlet method to support the
81 JSPTest example. It is envisaged that a more general method could be made
82 available for all frameworks in order to support access to underlying
83 request dispatchers and other framework facilities.
84 * Added more Jython-related documentation as suggested by Kevin Glynn.
85 * Added missing request headers for CGI/WSGI environment variables.
86 * Fixed Webware support to work with Webware 0.9.4.
87 * Fixed/improved Zope path value retrieval.
88 * Added support for wsgiref, changing the WSGI deploy function for CGI-based
89 applications to deploy_as_cgi and adding a deploy_with_wsgiref function.
90
91 New in WebStack 1.2.5 (Changes since WebStack 1.2.4)
92 ----------------------------------------------------
93
94 * Fixed mod_python status codes using a solution proposed by John Krukoff.
95 * Fixed a Twisted deprecation warning when accessing port numbers, thanks to
96 John Krukoff.
97 * Added Ubuntu Feisty (7.04) package support.
98 * Tidied up the documentation HTML.
99
100 New in WebStack 1.2.4 (Changes since WebStack 1.2.3)
101 ----------------------------------------------------
102
103 * Made a SessionDirectoryRepository which uses directories for data produced
104 by the shelve module, rather than attempting to manipulate files produced
105 by the shelve module, since the details of such files may differ between
106 environments: a situation noticed by John Krukoff in an environment
107 without the bsddb module installed.
108
109 New in WebStack 1.2.3 (Changes since WebStack 1.2.2)
110 ----------------------------------------------------
111
112 * Fixed inadvertent OpenSSL dependency, noticed by John Krukoff.
113
114 New in WebStack 1.2.2 (Changes since WebStack 1.2.1)
115 ----------------------------------------------------
116
117 * Added an EncodingSelector class for the setting of default encodings on
118 transactions.
119 * Added some documentation about path processing strategies.
120 * Added a secure variant of the BaseHTTPServer provided in the adapter for
121 BaseHTTPRequestHandler.
122
123 New in WebStack 1.2.1 (Changes since WebStack 1.2)
124 --------------------------------------------------
125
126 * Fixed mod_python get_content_type method.
127 * Fixed LoginResource form field processing; changed the field type to
128 password.
129 * Exposed LoginResource and LoginRedirectResource page contents as
130 attributes.
131 * Added documentation about extending LoginRedirectResource and using
132 PathSelector to remember an application's root path.
133 * Changed handle_errors to 1 throughout the examples.
134
135 New in WebStack 1.2 (Changes since WebStack 1.1.2)
136 --------------------------------------------------
137
138 * Added support for Django.
139 * Fixed documentation about the representation of file upload fields.
140 * Changed mod_python, Java Servlet and Webware (> 0.8.1) deployment to use a
141 deploy function instead of more complicated configuration mechanisms.
142 * Improved mod_python deployment documentation and tools so that cleaner
143 application paths/URLs can now be used.
144 * Moved user and path_info default definitions into WebStack.Generic as
145 class attributes.
146 * Fixed encoding usage issues with path fields when using get_fields in a
147 Zope environment.
148 * Added a FileResource class to WebStack.Resources.Static.
149 * Made DirectoryRepository convert filenames to Unicode in all cases.
150 * Renamed the Apache and Java Servlet tools, making them scripts which are
151 installed by setup.py.
152 * Fixed CGI content charsets and languages support.
153 * Fixed CGI cookie output.
154 * Added URL overriding in the LoginRedirectResource.
155 * Exposed a get_target function from WebStack.Resources.Login in order to
156 better support alternative login resources.
157 * Added improved error reporting for BaseHTTPRequestHandler, CGI, Django and
158 WSGI.
159 * Added a traverse_path method to the Transaction class.
160 * Made a path_encoding alias for urlencoding in the initialisation of
161 WebStack.Resources.ResourceMap objects.
162 * Added a Selectors module to WebStack.Resources in order to support common
163 resource selection patterns.
164
165 New in WebStack 1.1.2 (Changes since WebStack 1.1.1)
166 ----------------------------------------------------
167
168 * Fixed missing import in WebStack.Repositories.Directory.
169
170 New in WebStack 1.1.1 (Changes since WebStack 1.1)
171 --------------------------------------------------
172
173 * Fixed update_path to handle the root path properly.
174
175 New in WebStack 1.1 (Changes since WebStack 1.0)
176 ------------------------------------------------
177
178 * Added a Repositories package to provide session-like support for
179 different kinds of storage.
180 * Added an explicit filesystem encoding to the Calendar example and adopted
181 the DirectoryRepository from the Repositories package.
182 * Added get_path_without_info, update_path and redirect methods to the
183 Transaction class.
184 * Added get_attributes (attribute support) to the Transaction class.
185 * Added a values method to Helpers.Session.Wrapper.
186 * Fixed get_processed_virtual_path_info (to match from right to left).
187 * Improved/fixed exception handling in the adapters so that transactions are
188 committed as the final act of an adapter experiencing an unhandled
189 exception. This should result in session stores being closed properly.
190 * Changed the Helpers.Session.SessionStore to use DirectoryRepository.
191 * Made the "not found" behaviour of DirectoryResource more configurable.
192 * Added documentation for MapResource and DirectoryResource.
193 * Fixed the distribution names in the Ubuntu changelog.
194
195 New in WebStack 1.0 (Changes since WebStack 0.10)
196 -------------------------------------------------
197
198 * Changed the behaviour of get_path, get_path_without_query, get_path_info,
199 get_virtual_path_info, get_processed_virtual_path_info and
200 get_fields_from_path to return Unicode data decoded using the optional
201 encoding parameter or a common default encoding.
202 * Fixed file upload values so that FileContent objects are returned for such
203 fields in get_fields_from_body and get_fields.
204 (Warning! Except for Twisted!)
205 * Fixed the JavaServlet support so that streams and file content are
206 obtained as "almost" plain strings.
207 * Updated/fixed LoginResource and LoginRedirectResource to use the updated
208 path API and to handle special characters properly.
209 * Added convenience methods to Transaction for the decoding and encoding of
210 path values (to and from Unicode objects) - see the decode_path and
211 encode_path methods.
212 * Added the notion of processed virtual path info - the part of the original
213 path info not represented in the current virtual path info.
214 * Added "pass through" behaviour to ResourceMap.MapResource (prompted by a
215 patch from Scott Robinson).
216 * Fixed ResourceMap.MapResource to handle non-existent resources properly
217 (where the virtual path info is only one component in length).
218 * Added Debian package support.
219 * Added automatic session directory creation for the WebStack sessions
220 implementation.
221 * Added support for the repeated retrieval of sessions from the same
222 WebStack session store, avoiding deadlocks.
223 * Fixed the calendar example, making it perform a proper function.
224 * Made the BaseHTTPRequestHandler and Twisted SimpleWithLogin applications
225 include the Login application, since Konqueror (at least) does not share
226 cookies across different port numbers on the same host.
227 * Added the SimpleWithLogin and Login applications to the demonstration.
228 * Improved the documentation, adding information on request headers, and
229 describing file upload and session support limitations.
230 * Improved the AOLserver-related notes for CGI and Webware, adding a patch
231 for Webware in order to work around AOLserver issues.
232
233 New in WebStack 0.10 (Changes since WebStack 0.9)
234 -------------------------------------------------
235
236 * Changes to make the tools/demo.py script work on Windows (and other)
237 platforms (suggested by Jim Madsen).
238 * Fixed end of header newlines for CGI (suggested by Matt Harrison).
239 * Minor documentation fixes and improvements, adding information on
240 AOLserver in the CGI and Webware notes.
241 * Changed the mod_python server name method to use the server object rather
242 than the connection object.
243 * Added a parameter to the ResourceMap.MapResource class to permit automatic
244 redirects into resource hierarchies when no trailing "/" was given in the
245 URL; changed the updated virtual path info so that empty values may be set
246 (the guarantee that "/" will always appear no longer applies).
247 * Fixed virtual path info retrieval when the value is an empty string.
248
249 New in WebStack 0.9 (Changes since WebStack 0.8)
250 ------------------------------------------------
251
252 * Standardised error handling in the adapters so that tracebacks can be
253 suppressed and an internal server error condition raised.
254 * Added overriding of path info in transactions.
255 * Added a ResourceMap resource for dispatching to different resources
256 according to path components.
257 * Standardised deployment for some frameworks (see docs/deploying.html).
258 * Introductory documentation in XHTML format.
259 * Added server name and port methods to the transaction.
260 * Added a simple demonstration application, incorporating many of the
261 examples and launched under a single script.
262 * Fixed mod_python native sessions.
263 * Fixed Zope request stream access.
264 * WebStack is now licensed under the LGPL - see docs/COPYING.txt for
265 details.
266
267 New in WebStack 0.8 (Changes since WebStack 0.7)
268 ------------------------------------------------
269
270 * Added a standard exception, EndOfResponse, which can be used to
271 immediately stop the processing/production of a response; this is useful
272 when resources need to issue a redirect without unnecessary content being
273 generated, for example.
274 * Fixed path information for Zope.
275 * Added WSGI support.
276 * Verified Twisted 1.3.0 support with Python 2.3.3.
277
278 New in WebStack 0.7 (Changes since WebStack 0.6)
279 ------------------------------------------------
280
281 * Fixed path information semantics.
282 * Fixed file upload semantics.
283 * Fixed content type handling for Unicode output and for interpreting
284 request body fields/parameters (although some improvement remains).
285 * Added a method to discover the chosen response stream encoding.
286 * Fixed field/parameter retrieval so that path and body fields are distinct,
287 regardless of the framework employed.
288 * Added a method to get a combination of path and body fields (suggested by
289 Jacob Smullyan).
290 * Introduced Zope 2 support.
291 * Improved Jython/Java Servlet API support (although a special PyServlet
292 class must now be used, and certain libraries must be deployed with
293 applications).
294 * Introduced authentication/authorisation support for Jython/Java Servlet
295 API.
296 * Session support has been added (except for Webware 0.8.1).
297 * Alternative cookie support for mod_python has been added.
298 * Cookie support now supports encoded Unicode sequences for names and
299 values.
300
301 New in WebStack 0.6 (Changes since WebStack 0.5)
302 ------------------------------------------------
303
304 * Introduced Jython/Java Servlet API support.
305 * Minor fixes to example applications and to BaseHTTPRequestHandler.
306
307 New in WebStack 0.5 (Changes since WebStack 0.4)
308 ------------------------------------------------
309
310 * Changed request body fields/parameters so that they are now represented
311 using Unicode objects rather than plain strings.
312 * Introduced better support for Unicode in response streams.
313
314 New in WebStack 0.4 (Changes since WebStack 0.3)
315 ------------------------------------------------
316
317 * Added application definition of user identity, permitting alternative
318 authentication mechanisms.
319 * Improved BaseHTTPRequestHandler and mod_python reliability around fields
320 from request bodies.
321 * Provided stream and environment parameterisation in the CGI adapter.
322 * Added LoginRedirect and Login examples.
323 * Added get_path_without_query and fixed get_path behaviour.
324
325 New in WebStack 0.3 (Changes since WebStack 0.2)
326 ------------------------------------------------
327
328 * Added better header support for Webware (suggested by Ian Bicking).
329 * Introduced CGI and Java Servlet support (the latter is currently
330 broken/unfinished).
331 * Introduced support for cookies.
332
333 Future Work
334 -----------
335
336 (Essential)
337
338 Twisted 1.3.0 does not provide file upload metadata, and Twisted Web 0.5.0
339 also seems to be missing this functionality. It isn't obvious whether Twisted
340 Web2 will just copy its predecessors and provide a similarly limited API.
341 Perhaps the Twisted support needs to resemble the CGI support much more when
342 handling fields.
343
344 JythonServlet libraries need to be configured using sys.add_package when
345 these do not feature in the compiled-in list. Adding such configuration to
346 the handler may be most appropriate (since the web.xml file can be too
347 arcane), but this needs testing.
348
349 The algorithm employed in the WebStack.Helpers.Auth.get_token function
350 should be reviewed and improved for better security.
351
352 (Important)
353
354 Field access needs testing, especially for anything using the
355 cgi.FieldStorage class, and the way file uploads are exposed should be
356 reviewed (currently the meta-data is not exposed). The acquisition of fields
357 from specific sources should be tested with different request methods - some
358 frameworks provide path fields in the body fields dictionary, others (eg.
359 Zope) change the fields exposed depending on request method.
360
361 Interpretation of path field encodings needs to be verified. Currently,
362 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
363 ISO-8859-1, but it might be the case that some such fields might be
364 submitted as UTF-8. The decode_path method on Transaction does do much of the
365 work that is likely to be required, however. Still, a good policy for decoding
366 path fields, reducing the number of times one might specify the encoding in
367 various method calls, may be important.
368
369 An interesting test of encodings is to introduce things like the following to
370 the path info and query string sections of the URL: %25F0?%E6=%F8&%25F0=%F8
371 This should produce the following decoded result: %F0?æ=ø&%F0=ø
372 (The above needs to be read in ISO-8859-1 or ISO-8859-15.)
373
374 Cookie objects need defining strictly, especially since the standard library
375 Cookie object behaves differently to mod_python (and possibly Webware)
376 Cookie objects. Moreover, the set_cookie_value method needs to provide
377 access to the usual cookie parameters as supported by the frameworks. The
378 standard library Cookie module has issues with Unicode cookie names (and
379 possibly values) - this is worked around, but it would be best to resolve
380 this comprehensively.
381
382 UTF-16 (and possibly other encodings) causes problems with HTML form data
383 sent in POST requests using the application/x-www-form-urlencoded content
384 type. This should be reviewed at a later date when proper standardisation
385 has taken place.
386
387 Session support, especially through WebStack.Helpers.Session, should be
388 reviewed and be made compatible with non-cookie mechanisms.
389
390 Locking in the session support and in DirectoryRepository should be improved.
391
392 HeaderValue objects should be employed more extensively. Thus, the header
393 access methods may need to change their behaviour slightly. The get_headers
394 method should potentially return a list for each item in the dictionary.
395
396 WSGI support could demand that a special "end of headers" method be
397 introduced into WebStack, thus making response output more efficient (and
398 probably also for other frameworks, too).
399
400 Investigate proper support for HEAD, OPTIONS and other request methods.
401
402 Consider packages for different operating systems (other than Debian).
403
404 Investigate cStringIO usage.
405
406 The location of deployed applications in the filesystem should be exposed to
407 those applications. (This is actually available in the __file__ module
408 variable.) A resource could be provided to record the "root" path and added to
409 a resource hierarchy or site map. Note that PathSelector records the "root"
410 path, although it is not automatically deployed.
411
412 (Completed/rejected)
413
414 Path information should be consistent across all frameworks, and the "path
415 info" value should be meaningful. (This should now be correct.)
416
417 Investigate the nicer functions in the cgi module, discarding the "magic"
418 stuff like FieldStorage. (These nicer functions are used by projects like
419 Twisted - as of 1.3.0 at least - and do not give the necessary information we
420 require.)
421
422 Release Procedures
423 ------------------
424
425 Update the WebStack/__init__.py __version__ attribute.
426 Change the version number and package filename/directory in the documentation.
427 Change code examples in the documentation if appropriate.
428 Update the release notes (see above).
429 Check the setup.py file and ensure that all package directories are mentioned.
430 Check the release information in the PKG-INFO file and in the package
431 changelog (and other files).
432 Tag, export.
433 Generate the PyServlet classes.
434 Generate the API documentation.
435 Remove generated .pyc files: rm `find . -name "*.pyc"`
436 Archive, upload.
437 Upload the introductory documentation.
438 Update PyPI, PythonInfo Wiki entries.
439
440 Generating the PyServlet Classes
441 --------------------------------
442
443 In order to generate the PyServlet classes, it is necessary to run the
444 supplied script:
445
446 ./tools/JavaServlet/compile.sh
447
448 This produces Java classes and a .jar file for use by WebStack applications
449 running on the Java platform.
450
451 Generating the API Documentation
452 --------------------------------
453
454 In order to prepare the API documentation, it is necessary to generate some
455 Web pages from the Python source code. For this, the epydoc application must
456 be available on your system. Then, inside the distribution directory, run the
457 apidocs.sh tool script as follows:
458
459 ./tools/apidocs.sh
460
461 Some warnings may be generated by the script, but the result should be a new
462 apidocs directory within the distribution directory.
463
464 Making Packages
465 ---------------
466
467 To make Debian-based packages:
468
469 1. Create new package directories under packages if necessary.
470 2. Make a symbolic link in the distribution's root directory to keep the
471 Debian tools happy. For example, one of the following:
472
473 ln -s packages/ubuntu-hoary/python2.4-webstack/debian/
474 ln -s packages/ubuntu-feisty/python-webstack/debian/
475 ln -s packages/ubuntu-feisty/jython-webstack/debian/
476
477 3. Run the package builder:
478
479 dpkg-buildpackage -rfakeroot
480
481 4. Locate and tidy up the packages in the parent directory of the
482 distribution's root directory.