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