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