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