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 Currently, BaseHTTPRequestHandler (via BaseHTTPServer in the standard
36 library), CGI, Jython/Java Servlet API, mod_python, Twisted, Webware, WSGI
37 and Zope 2 are supported. Each framework has its own set of strengths and
38 weaknesses, but the idea is that deployment concerns can be considered
39 separately from the implementation of application functionality. Consult the
40 NOTES.txt files in each framework's subdirectory of the docs directory for
41 some notes on how applications may be run in each environment.
42
43 Tested Frameworks Release Information
44 ----------------- -------------------
45
46 BaseHTTPRequestHandler Python 2.2.2, Python 2.3.3, Python 2.4.1
47 CGI Apache 2.0.44, Apache 2.0.53, AOLserver 4.0.10, lighttpd 1.3.15
48 Jython/Java Servlet API Jython 2.1, Java JDK 1.3.1_02, Tomcat 4.1.31 (Servlet 2.3)
49 mod_python 3.0.3 (3.1.3 for framework cookie and session support)
50 Twisted 1.0.5, 1.3.0
51 Webware 0.8.1, CVS (2004-02-06), 0.9b2
52 WSGI run_with_cgi (PEP 333)
53 Zope 2.7.2-0, 2.8.0-final
54
55 New in WebStack 1.0 (Changes since WebStack 0.10)
56 -------------------------------------------------
57
58 Changed the behaviour of get_path, get_path_without_query, get_path_info,
59 get_virtual_path_info, get_processed_virtual_path_info and
60 get_fields_from_path to return Unicode data decoded using the optional
61 encoding parameter or a common default encoding.
62 Added convenience methods to Transaction for the decoding and encoding of path
63 values (to and from Unicode objects) - see the decode_path and encode_path
64 methods.
65 Added the notion of processed virtual path info - the part of the original
66 path info not represented in the current virtual path info.
67 Added "pass through" behaviour to ResourceMap.MapResource (prompted by a patch
68 from Scott Robinson).
69 Fixed ResourceMap.MapResource to handle non-existent resources properly (where
70 the virtual path info is only one component in length).
71 Added Debian package support.
72 Added automatic session directory creation for the WebStack sessions
73 implementation.
74 Added support for the repeated retrieval of sessions from the same WebStack
75 session store, avoiding deadlocks.
76 Fixed the calendar example, making it perform a proper function.
77
78 New in WebStack 0.10 (Changes since WebStack 0.9)
79 -------------------------------------------------
80
81 Changes to make the tools/demo.py script work on Windows (and other) platforms
82 (suggested by Jim Madsen).
83 Fixed end of header newlines for CGI (suggested by Matt Harrison).
84 Minor documentation fixes and improvements, adding information on AOLserver in
85 the CGI and Webware notes.
86 Changed the mod_python server name method to use the server object rather than
87 the connection object.
88 Added a parameter to the ResourceMap.MapResource class to permit automatic
89 redirects into resource hierarchies when no trailing "/" was given in the URL;
90 changed the updated virtual path info so that empty values may be set (the
91 guarantee that "/" will always appear no longer applies).
92 Fixed virtual path info retrieval when the value is an empty string.
93
94 New in WebStack 0.9 (Changes since WebStack 0.8)
95 ------------------------------------------------
96
97 Standardised error handling in the adapters so that tracebacks can be
98 suppressed and an internal server error condition raised.
99 Added overriding of path info in transactions.
100 Added a ResourceMap resource for dispatching to different resources
101 according to path components.
102 Standardised deployment for some frameworks (see docs/deploying.html).
103 Introductory documentation in XHTML format.
104 Added server name and port methods to the transaction.
105 Added a simple demonstration application, incorporating many of the examples
106 and launched under a single script.
107 Fixed mod_python native sessions.
108 Fixed Zope request stream access.
109 WebStack is now licensed under the LGPL - see docs/COPYING.txt for details.
110
111 New in WebStack 0.8 (Changes since WebStack 0.7)
112 ------------------------------------------------
113
114 Added a standard exception, EndOfResponse, which can be used to immediately
115 stop the processing/production of a response; this is useful when resources
116 need to issue a redirect without unnecessary content being generated, for
117 example.
118 Fixed path information for Zope.
119 Added WSGI support.
120 Verified Twisted 1.3.0 support with Python 2.3.3.
121
122 New in WebStack 0.7 (Changes since WebStack 0.6)
123 ------------------------------------------------
124
125 Fixed path information semantics.
126 Fixed file upload semantics.
127 Fixed content type handling for Unicode output and for interpreting request
128 body fields/parameters (although some improvement remains).
129 Added a method to discover the chosen response stream encoding.
130 Fixed field/parameter retrieval so that path and body fields are distinct,
131 regardless of the framework employed.
132 Added a method to get a combination of path and body fields (suggested by
133 Jacob Smullyan).
134 Introduced Zope 2 support.
135 Improved Jython/Java Servlet API support (although a special PyServlet class
136 must now be used, and certain libraries must be deployed with applications).
137 Introduced authentication/authorisation support for Jython/Java Servlet API.
138 Session support has been added (except for Webware 0.8.1).
139 Alternative cookie support for mod_python has been added.
140 Cookie support now supports encoded Unicode sequences for names and values.
141
142 New in WebStack 0.6 (Changes since WebStack 0.5)
143 ------------------------------------------------
144
145 Introduced Jython/Java Servlet API support.
146 Minor fixes to example applications and to BaseHTTPRequestHandler.
147
148 New in WebStack 0.5 (Changes since WebStack 0.4)
149 ------------------------------------------------
150
151 Changed request body fields/parameters so that they are now represented
152 using Unicode objects rather than plain strings.
153 Introduced better support for Unicode in response streams.
154
155 New in WebStack 0.4 (Changes since WebStack 0.3)
156 ------------------------------------------------
157
158 Added application definition of user identity, permitting alternative
159 authentication mechanisms.
160 Improved BaseHTTPRequestHandler and mod_python reliability around fields
161 from request bodies.
162 Provided stream and environment parameterisation in the CGI adapter.
163 Added LoginRedirect and Login examples.
164 Added get_path_without_query and fixed get_path behaviour.
165
166 New in WebStack 0.3 (Changes since WebStack 0.2)
167 ------------------------------------------------
168
169 Added better header support for Webware (suggested by Ian Bicking).
170 Introduced CGI and Java Servlet support (the latter is currently
171 broken/unfinished).
172 Introduced support for cookies.
173
174 Future Work
175 -----------
176
177 (Essential)
178
179 JythonServlet libraries need to be configured using sys.add_package when
180 these do not feature in the compiled-in list. Adding such configuration to
181 the handler may be most appropriate (since the web.xml file can be too
182 arcane), but this needs testing.
183
184 (Important)
185
186 Things to consider for future releases: improved cookie support, redirects,
187 access to shared resources and much better documentation.
188
189 Field access needs testing, especially for anything using the
190 cgi.FieldStorage class, and the way file uploads are exposed should be
191 reviewed (currently the meta-data is not exposed). The acquisition of fields
192 from specific sources should be tested with different request methods - some
193 frameworks provide path fields in the body fields dictionary, others (eg.
194 Zope) change the fields exposed depending on request method.
195
196 Interpretation of path field encodings needs to be verified. Currently,
197 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
198 ISO-8859-1, but it might be the case that some such fields might be
199 submitted as UTF-8. The decode_path method on Transaction does do much of the
200 work that is likely to be required, however.
201
202 An interesting test of encodings is to introduce things like the following to
203 the path info and query string sections of the URL: %25F0?%E6=%F8&%25F0=%F8
204 This should produce the following decoded result: %F0?æ=ø&%F0=ø
205 (The above needs to be read in ISO-8859-1 or ISO-8859-15.)
206
207 Cookie objects need defining strictly, especially since the standard library
208 Cookie object behaves differently to mod_python (and possibly Webware)
209 Cookie objects. Moreover, the set_cookie_value method needs to provide
210 access to the usual cookie parameters as supported by the frameworks. The
211 standard library Cookie module has issues with Unicode cookie names (and
212 possibly values) - this is worked around, but it would be best to resolve
213 this comprehensively.
214
215 UTF-16 (and possibly other encodings) causes problems with HTML form data
216 sent in POST requests using the application/x-www-form-urlencoded content
217 type. This should be reviewed at a later date when proper standardisation
218 has taken place.
219
220 Session support, especially through WebStack.Helpers.Session, should be
221 reviewed and be made compatible with non-cookie mechanisms.
222
223 HeaderValue objects should be employed more extensively. Thus, the header
224 access methods may need to change their behaviour slightly.
225
226 Investigate the nicer functions in the cgi module, discarding the "magic"
227 stuff like FieldStorage.
228
229 WSGI support could demand that a special "end of headers" method be
230 introduced into WebStack, thus making response output more efficient (and
231 probably also for other frameworks, too).
232
233 The algorithm employed in the WebStack.Helpers.Auth.get_token function
234 should be reviewed and improved for better security.
235
236 Investigate proper support for HEAD, OPTIONS and other request methods.
237
238 Consider packages for different operating systems (other than Debian).
239
240 (Completed/rejected)
241
242 The location of deployed applications in the filesystem should be exposed to
243 those applications. (This is actually available in the __file__ module
244 variable.)
245
246 Path information should be consistent across all frameworks, and the "path
247 info" value should be meaningful. (This should now be correct.)
248
249 Release Procedures
250 ------------------
251
252 Update the WebStack/__init__.py __version__ attribute.
253 Change the version number and package filename/directory in the documentation.
254 Change code examples in the documentation if appropriate.
255 Update the release notes (see above).
256 Check the setup.py file and ensure that all package directories are mentioned.
257 Check the release information in the PKG-INFO file and in the package
258 changelog (and other files).
259 Tag, export.
260 Generate the PyServlet classes.
261 Generate the API documentation.
262 Remove generated .pyc files: rm `find . -name "*.pyc"`
263 Archive, upload.
264 Upload the introductory documentation.
265 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
266
267 Generating the API Documentation
268 --------------------------------
269
270 In order to prepare the API documentation, it is necessary to generate some
271 Web pages from the Python source code. For this, the epydoc application must
272 be available on your system. Then, inside the WebStack directory, run the
273 apidocs.sh tool script as follows:
274
275 ./tools/apidocs.sh
276
277 Some warnings may be generated by the script, but the result should be a new
278 apidocs directory within the WebStack directory.
