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