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