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