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