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