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