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