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