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 Currently, BaseHTTPRequestHandler (via BaseHTTPServer in the standard
36 library), CGI, Jython/Java Servlet API, mod_python, Twisted, Webware, WSGI
37 and Zope 2 are supported. Each framework has its own set of strengths and
38 weaknesses, but the idea is that deployment concerns can be considered
39 separately from the implementation of application functionality. Consult the
40 NOTES.txt files in each framework's subdirectory of the docs directory for
41 some notes on how applications may be run in each environment.
42
43 Tested Frameworks Release Information
44 ----------------- -------------------
45
46 BaseHTTPRequestHandler Python 2.2.2, Python 2.3.3, Python 2.4.1
47 CGI Apache 2.0.44, Apache 2.0.53, AOLserver 4.0.10, lighttpd 1.3.15
48 Django 0.91
49 Jython/Java Servlet API Jython 2.1, Java JDK 1.3.1_02, Tomcat 4.1.31 (Servlet 2.3)
50 mod_python 3.0.3 (3.1.3 for framework cookie and session support)
51 Twisted 1.0.5, 1.3.0
52 Webware 0.8.1, CVS (2004-02-06), 0.9b2
53 WSGI run_with_cgi (PEP 333)
54 Zope 2.7.2-0, 2.8.0-final
55
56 New in WebStack 1.2 (Changes since WebStack 1.1.2)
57 --------------------------------------------------
58
59 * Added support for Django.
60 * Fixed documentation about the representation of file upload fields.
61 * Changed mod_python, Java Servlet and Webware (> 0.8.1) deployment to use a
62 deploy function instead of more complicated configuration mechanisms.
63 * Improved mod_python deployment documentation and tools so that cleaner
64 application paths/URLs can now be used.
65 * Moved user and path_info default definitions into WebStack.Generic as
66 class attributes.
67 * Fixed encoding usage issues with path fields when using get_fields in a
68 Zope environment.
69 * Added a FileResource class to WebStack.Resources.Static.
70 * Made DirectoryRepository convert filenames to Unicode in all cases.
71 * Renamed the Apache and Java Servlet tools, making them scripts which are
72 installed by setup.py.
73
74 New in WebStack 1.1.2 (Changes since WebStack 1.1.1)
75 ----------------------------------------------------
76
77 * Fixed missing import in WebStack.Repositories.Directory.
78
79 New in WebStack 1.1.1 (Changes since WebStack 1.1)
80 --------------------------------------------------
81
82 * Fixed update_path to handle the root path properly.
83
84 New in WebStack 1.1 (Changes since WebStack 1.0)
85 ------------------------------------------------
86
87 * Added a Repositories package to provide session-like support for
88 different kinds of storage.
89 * Added an explicit filesystem encoding to the Calendar example and adopted
90 the DirectoryRepository from the Repositories package.
91 * Added get_path_without_info, update_path and redirect methods to the
92 Transaction class.
93 * Added get_attributes (attribute support) to the Transaction class.
94 * Added a values method to Helpers.Session.Wrapper.
95 * Fixed get_processed_virtual_path_info (to match from right to left).
96 * Improved/fixed exception handling in the adapters so that transactions are
97 committed as the final act of an adapter experiencing an unhandled
98 exception. This should result in session stores being closed properly.
99 * Changed the Helpers.Session.SessionStore to use DirectoryRepository.
100 * Made the "not found" behaviour of DirectoryResource more configurable.
101 * Added documentation for MapResource and DirectoryResource.
102 * Fixed the distribution names in the Ubuntu changelog.
103
104 New in WebStack 1.0 (Changes since WebStack 0.10)
105 -------------------------------------------------
106
107 * Changed the behaviour of get_path, get_path_without_query, get_path_info,
108 get_virtual_path_info, get_processed_virtual_path_info and
109 get_fields_from_path to return Unicode data decoded using the optional
110 encoding parameter or a common default encoding.
111 * Fixed file upload values so that FileContent objects are returned for such
112 fields in get_fields_from_body and get_fields.
113 (Warning! Except for Twisted!)
114 * Fixed the JavaServlet support so that streams and file content are
115 obtained as "almost" plain strings.
116 * Updated/fixed LoginResource and LoginRedirectResource to use the updated
117 path API and to handle special characters properly.
118 * Added convenience methods to Transaction for the decoding and encoding of
119 path values (to and from Unicode objects) - see the decode_path and
120 encode_path methods.
121 * Added the notion of processed virtual path info - the part of the original
122 path info not represented in the current virtual path info.
123 * Added "pass through" behaviour to ResourceMap.MapResource (prompted by a
124 patch from Scott Robinson).
125 * Fixed ResourceMap.MapResource to handle non-existent resources properly
126 (where the virtual path info is only one component in length).
127 * Added Debian package support.
128 * Added automatic session directory creation for the WebStack sessions
129 implementation.
130 * Added support for the repeated retrieval of sessions from the same
131 WebStack session store, avoiding deadlocks.
132 * Fixed the calendar example, making it perform a proper function.
133 * Made the BaseHTTPRequestHandler and Twisted SimpleWithLogin applications
134 include the Login application, since Konqueror (at least) does not share
135 cookies across different port numbers on the same host.
136 * Added the SimpleWithLogin and Login applications to the demonstration.
137 * Improved the documentation, adding information on request headers, and
138 describing file upload and session support limitations.
139 * Improved the AOLserver-related notes for CGI and Webware, adding a patch
140 for Webware in order to work around AOLserver issues.
141
142 New in WebStack 0.10 (Changes since WebStack 0.9)
143 -------------------------------------------------
144
145 * Changes to make the tools/demo.py script work on Windows (and other)
146 platforms (suggested by Jim Madsen).
147 * Fixed end of header newlines for CGI (suggested by Matt Harrison).
148 * Minor documentation fixes and improvements, adding information on
149 AOLserver in the CGI and Webware notes.
150 * Changed the mod_python server name method to use the server object rather
151 than the connection object.
152 * Added a parameter to the ResourceMap.MapResource class to permit automatic
153 redirects into resource hierarchies when no trailing "/" was given in the
154 URL; changed the updated virtual path info so that empty values may be set
155 (the guarantee that "/" will always appear no longer applies).
156 * Fixed virtual path info retrieval when the value is an empty string.
157
158 New in WebStack 0.9 (Changes since WebStack 0.8)
159 ------------------------------------------------
160
161 * Standardised error handling in the adapters so that tracebacks can be
162 suppressed and an internal server error condition raised.
163 * Added overriding of path info in transactions.
164 * Added a ResourceMap resource for dispatching to different resources
165 according to path components.
166 * Standardised deployment for some frameworks (see docs/deploying.html).
167 * Introductory documentation in XHTML format.
168 * Added server name and port methods to the transaction.
169 * Added a simple demonstration application, incorporating many of the
170 examples and launched under a single script.
171 * Fixed mod_python native sessions.
172 * Fixed Zope request stream access.
173 * WebStack is now licensed under the LGPL - see docs/COPYING.txt for
174 details.
175
176 New in WebStack 0.8 (Changes since WebStack 0.7)
177 ------------------------------------------------
178
179 * Added a standard exception, EndOfResponse, which can be used to
180 immediately stop the processing/production of a response; this is useful
181 when resources need to issue a redirect without unnecessary content being
182 generated, for example.
183 * Fixed path information for Zope.
184 * Added WSGI support.
185 * Verified Twisted 1.3.0 support with Python 2.3.3.
186
187 New in WebStack 0.7 (Changes since WebStack 0.6)
188 ------------------------------------------------
189
190 * Fixed path information semantics.
191 * Fixed file upload semantics.
192 * Fixed content type handling for Unicode output and for interpreting
193 request body fields/parameters (although some improvement remains).
194 * Added a method to discover the chosen response stream encoding.
195 * Fixed field/parameter retrieval so that path and body fields are distinct,
196 regardless of the framework employed.
197 * Added a method to get a combination of path and body fields (suggested by
198 Jacob Smullyan).
199 * Introduced Zope 2 support.
200 * Improved Jython/Java Servlet API support (although a special PyServlet
201 class must now be used, and certain libraries must be deployed with
202 applications).
203 * Introduced authentication/authorisation support for Jython/Java Servlet
204 API.
205 * Session support has been added (except for Webware 0.8.1).
206 * Alternative cookie support for mod_python has been added.
207 * Cookie support now supports encoded Unicode sequences for names and
208 values.
209
210 New in WebStack 0.6 (Changes since WebStack 0.5)
211 ------------------------------------------------
212
213 * Introduced Jython/Java Servlet API support.
214 * Minor fixes to example applications and to BaseHTTPRequestHandler.
215
216 New in WebStack 0.5 (Changes since WebStack 0.4)
217 ------------------------------------------------
218
219 * Changed request body fields/parameters so that they are now represented
220 using Unicode objects rather than plain strings.
221 * Introduced better support for Unicode in response streams.
222
223 New in WebStack 0.4 (Changes since WebStack 0.3)
224 ------------------------------------------------
225
226 * Added application definition of user identity, permitting alternative
227 authentication mechanisms.
228 * Improved BaseHTTPRequestHandler and mod_python reliability around fields
229 from request bodies.
230 * Provided stream and environment parameterisation in the CGI adapter.
231 * Added LoginRedirect and Login examples.
232 * Added get_path_without_query and fixed get_path behaviour.
233
234 New in WebStack 0.3 (Changes since WebStack 0.2)
235 ------------------------------------------------
236
237 * Added better header support for Webware (suggested by Ian Bicking).
238 * Introduced CGI and Java Servlet support (the latter is currently
239 broken/unfinished).
240 * Introduced support for cookies.
241
242 Future Work
243 -----------
244
245 (Essential)
246
247 Twisted 1.3.0 does not provide file upload metadata, and Twisted Web 0.5.0
248 also seems to be missing this functionality. It isn't obvious whether Twisted
249 Web2 will just copy its predecessors and provide a similarly limited API.
250 Perhaps the Twisted support needs to resemble the CGI support much more when
251 handling fields.
252
253 JythonServlet libraries need to be configured using sys.add_package when
254 these do not feature in the compiled-in list. Adding such configuration to
255 the handler may be most appropriate (since the web.xml file can be too
256 arcane), but this needs testing.
257
258 (Important)
259
260 Field access needs testing, especially for anything using the
261 cgi.FieldStorage class, and the way file uploads are exposed should be
262 reviewed (currently the meta-data is not exposed). The acquisition of fields
263 from specific sources should be tested with different request methods - some
264 frameworks provide path fields in the body fields dictionary, others (eg.
265 Zope) change the fields exposed depending on request method.
266
267 Interpretation of path field encodings needs to be verified. Currently,
268 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
269 ISO-8859-1, but it might be the case that some such fields might be
270 submitted as UTF-8. The decode_path method on Transaction does do much of the
271 work that is likely to be required, however. Still, a good policy for decoding
272 path fields, reducing the number of times one might specify the encoding in
273 various method calls, may be important.
274
275 An interesting test of encodings is to introduce things like the following to
276 the path info and query string sections of the URL: %25F0?%E6=%F8&%25F0=%F8
277 This should produce the following decoded result: %F0?æ=ø&%F0=ø
278 (The above needs to be read in ISO-8859-1 or ISO-8859-15.)
279
280 Cookie objects need defining strictly, especially since the standard library
281 Cookie object behaves differently to mod_python (and possibly Webware)
282 Cookie objects. Moreover, the set_cookie_value method needs to provide
283 access to the usual cookie parameters as supported by the frameworks. The
284 standard library Cookie module has issues with Unicode cookie names (and
285 possibly values) - this is worked around, but it would be best to resolve
286 this comprehensively.
287
288 UTF-16 (and possibly other encodings) causes problems with HTML form data
289 sent in POST requests using the application/x-www-form-urlencoded content
290 type. This should be reviewed at a later date when proper standardisation
291 has taken place.
292
293 Session support, especially through WebStack.Helpers.Session, should be
294 reviewed and be made compatible with non-cookie mechanisms.
295
296 Locking in the session support and in DirectoryRepository should be improved.
297
298 HeaderValue objects should be employed more extensively. Thus, the header
299 access methods may need to change their behaviour slightly. The get_headers
300 method should potentially return a list for each item in the dictionary.
301
302 WSGI support could demand that a special "end of headers" method be
303 introduced into WebStack, thus making response output more efficient (and
304 probably also for other frameworks, too).
305
306 The algorithm employed in the WebStack.Helpers.Auth.get_token function
307 should be reviewed and improved for better security.
308
309 Investigate proper support for HEAD, OPTIONS and other request methods.
310
311 Consider packages for different operating systems (other than Debian).
312
313 Provide some 500 error content when handle_errors is true.
314
315 Investigate cStringIO usage.
316
317 (Completed/rejected)
318
319 The location of deployed applications in the filesystem should be exposed to
320 those applications. (This is actually available in the __file__ module
321 variable.)
322
323 Path information should be consistent across all frameworks, and the "path
324 info" value should be meaningful. (This should now be correct.)
325
326 Investigate the nicer functions in the cgi module, discarding the "magic"
327 stuff like FieldStorage. (These nicer functions are used by projects like
328 Twisted - as of 1.3.0 at least - and do not give the necessary information we
329 require.)
330
331 Release Procedures
332 ------------------
333
334 Update the WebStack/__init__.py __version__ attribute.
335 Change the version number and package filename/directory in the documentation.
336 Change code examples in the documentation if appropriate.
337 Update the release notes (see above).
338 Check the setup.py file and ensure that all package directories are mentioned.
339 Check the release information in the PKG-INFO file and in the package
340 changelog (and other files).
341 Tag, export.
342 Generate the PyServlet classes.
343 Generate the API documentation.
344 Remove generated .pyc files: rm `find . -name "*.pyc"`
345 Archive, upload.
346 Upload the introductory documentation.
347 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
348
349 Generating the API Documentation
350 --------------------------------
351
352 In order to prepare the API documentation, it is necessary to generate some
353 Web pages from the Python source code. For this, the epydoc application must
354 be available on your system. Then, inside the distribution directory, run the
355 apidocs.sh tool script as follows:
356
357 ./tools/apidocs.sh
358
359 Some warnings may be generated by the script, but the result should be a new
360 apidocs directory within the distribution directory.
361
362 Making Packages
363 ---------------
364
365 To make Debian-based packages:
366
367 1. Create new package directories under packages if necessary.
368 2. Make a symbolic link in the distribution's root directory to keep the
369 Debian tools happy:
370
371 ln -s packages/ubuntu-hoary/python2.4-webstack/debian/
372
373 3. Run the package builder:
374
375 dpkg-buildpackage -rfakeroot
376
377 4. Locate and tidy up the packages in the parent directory of the
378 distribution's root directory.
