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