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