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 4.1.27 (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)
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_fields_from_path to return Unicode data decoded
59 using the optional encoding parameter or a common default encoding.
60 Added Debian package support.
61 Added automatic session directory creation for the WebStack sessions
62 implementation.
63 Added support for the repeated retrieval of sessions from the same WebStack
64 session store, avoiding deadlocks.
65 Fixed the calendar example, making it perform a proper function.
66 Added the notion of processed virtual path info - the part of the original
67 path info not represented in the current virtual path info.
68 Added "pass through" behaviour to ResourceMap.MapResource (prompted by a patch
69 from Scott Robinson).
70 Fixed ResourceMap.MapResource to handle non-existent resources properly (where
71 the virtual path info is only one component in length).
72 Added convenience methods to Transaction for the decoding and encoding of path
73 values (to and from Unicode objects) - see the decode_path and encode_path
74 methods.
75
76 New in WebStack 0.10 (Changes since WebStack 0.9)
77 -------------------------------------------------
78
79 Changes to make the tools/demo.py script work on Windows (and other) platforms
80 (suggested by Jim Madsen).
81 Fixed end of header newlines for CGI (suggested by Matt Harrison).
82 Minor documentation fixes and improvements, adding information on AOLserver in
83 the CGI and Webware notes.
84 Changed the mod_python server name method to use the server object rather than
85 the connection object.
86 Added a parameter to the ResourceMap.MapResource class to permit automatic
87 redirects into resource hierarchies when no trailing "/" was given in the URL;
88 changed the updated virtual path info so that empty values may be set (the
89 guarantee that "/" will always appear no longer applies).
90 Fixed virtual path info retrieval when the value is an empty string.
91
92 New in WebStack 0.9 (Changes since WebStack 0.8)
93 ------------------------------------------------
94
95 Standardised error handling in the adapters so that tracebacks can be
96 suppressed and an internal server error condition raised.
97 Added overriding of path info in transactions.
98 Added a ResourceMap resource for dispatching to different resources
99 according to path components.
100 Standardised deployment for some frameworks (see docs/deploying.html).
101 Introductory documentation in XHTML format.
102 Added server name and port methods to the transaction.
103 Added a simple demonstration application, incorporating many of the examples
104 and launched under a single script.
105 Fixed mod_python native sessions.
106 Fixed Zope request stream access.
107 WebStack is now licensed under the LGPL - see docs/COPYING.txt for details.
108
109 New in WebStack 0.8 (Changes since WebStack 0.7)
110 ------------------------------------------------
111
112 Added a standard exception, EndOfResponse, which can be used to immediately
113 stop the processing/production of a response; this is useful when resources
114 need to issue a redirect without unnecessary content being generated, for
115 example.
116 Fixed path information for Zope.
117 Added WSGI support.
118 Verified Twisted 1.3.0 support with Python 2.3.3.
119
120 New in WebStack 0.7 (Changes since WebStack 0.6)
121 ------------------------------------------------
122
123 Fixed path information semantics.
124 Fixed file upload semantics.
125 Fixed content type handling for Unicode output and for interpreting request
126 body fields/parameters (although some improvement remains).
127 Added a method to discover the chosen response stream encoding.
128 Fixed field/parameter retrieval so that path and body fields are distinct,
129 regardless of the framework employed.
130 Added a method to get a combination of path and body fields (suggested by
131 Jacob Smullyan).
132 Introduced Zope 2 support.
133 Improved Jython/Java Servlet API support (although a special PyServlet class
134 must now be used, and certain libraries must be deployed with applications).
135 Introduced authentication/authorisation support for Jython/Java Servlet API.
136 Session support has been added (except for Webware 0.8.1).
137 Alternative cookie support for mod_python has been added.
138 Cookie support now supports encoded Unicode sequences for names and values.
139
140 New in WebStack 0.6 (Changes since WebStack 0.5)
141 ------------------------------------------------
142
143 Introduced Jython/Java Servlet API support.
144 Minor fixes to example applications and to BaseHTTPRequestHandler.
145
146 New in WebStack 0.5 (Changes since WebStack 0.4)
147 ------------------------------------------------
148
149 Changed request body fields/parameters so that they are now represented
150 using Unicode objects rather than plain strings.
151 Introduced better support for Unicode in response streams.
152
153 New in WebStack 0.4 (Changes since WebStack 0.3)
154 ------------------------------------------------
155
156 Added application definition of user identity, permitting alternative
157 authentication mechanisms.
158 Improved BaseHTTPRequestHandler and mod_python reliability around fields
159 from request bodies.
160 Provided stream and environment parameterisation in the CGI adapter.
161 Added LoginRedirect and Login examples.
162 Added get_path_without_query and fixed get_path behaviour.
163
164 New in WebStack 0.3 (Changes since WebStack 0.2)
165 ------------------------------------------------
166
167 Added better header support for Webware (suggested by Ian Bicking).
168 Introduced CGI and Java Servlet support (the latter is currently
169 broken/unfinished).
170 Introduced support for cookies.
171
172 Future Work
173 -----------
174
175 (Essential)
176
177 JythonServlet libraries need to be configured using sys.add_package when
178 these do not feature in the compiled-in list. Adding such configuration to
179 the handler may be most appropriate (since the web.xml file can be too
180 arcane), but this needs testing.
181
182 (Important)
183
184 Things to consider for future releases: improved cookie support, redirects,
185 access to shared resources and much better documentation.
186
187 Field access needs testing, especially for anything using the
188 cgi.FieldStorage class, and the way file uploads are exposed should be
189 reviewed (currently the meta-data is not exposed). The acquisition of fields
190 from specific sources should be tested with different request methods - some
191 frameworks provide path fields in the body fields dictionary, others (eg.
192 Zope) change the fields exposed depending on request method.
193
194 Interpretation of path field encodings needs to be verified. Currently,
195 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
196 ISO-8859-1, but it might be the case that some such fields might be
197 submitted as UTF-8.
198
199 Cookie objects need defining strictly, especially since the standard library
200 Cookie object behaves differently to mod_python (and possibly Webware)
201 Cookie objects. Moreover, the set_cookie_value method needs to provide
202 access to the usual cookie parameters as supported by the frameworks. The
203 standard library Cookie module has issues with Unicode cookie names (and
204 possibly values) - this is worked around, but it would be best to resolve
205 this comprehensively.
206
207 UTF-16 (and possibly other encodings) causes problems with HTML form data
208 sent in POST requests using the application/x-www-form-urlencoded content
209 type. This should be reviewed at a later date when proper standardisation
210 has taken place.
211
212 Session support, especially through WebStack.Helpers.Session, should be
213 reviewed and be made compatible with non-cookie mechanisms.
214
215 HeaderValue objects should be employed more extensively. Thus, the header
216 access methods may need to change their behaviour slightly.
217
218 Investigate the nicer functions in the cgi module, discarding the "magic"
219 stuff like FieldStorage.
220
221 WSGI support could demand that a special "end of headers" method be
222 introduced into WebStack, thus making response output more efficient (and
223 probably also for other frameworks, too).
224
225 The algorithm employed in the WebStack.Helpers.Auth.get_token function
226 should be reviewed and improved for better security.
227
228 Investigate proper support for HEAD, OPTIONS and other request methods.
229
230 Consider packages for different operating systems.
231
232 (Completed/rejected)
233
234 The location of deployed applications in the filesystem should be exposed to
235 those applications. (This is actually available in the __file__ module
236 variable.)
237
238 Path information should be consistent across all frameworks, and the "path
239 info" value should be meaningful. (This should now be correct.)
240
241 Release Procedures
242 ------------------
243
244 Update the WebStack/__init__.py __version__ attribute.
245 Change the version number and package filename/directory in the documentation.
246 Change code examples in the documentation if appropriate.
247 Update the release notes (see above).
248 Check the setup.py file and ensure that all package directories are mentioned.
249 Check the release information in the PKG-INFO file and in the package
250 changelog (and other files).
251 Tag, export.
252 Generate the PyServlet classes.
253 Generate the API documentation.
254 Remove generated .pyc files: rm `find . -name "*.pyc"`
255 Archive, upload.
256 Upload the introductory documentation.
257 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
258
259 Generating the API Documentation
260 --------------------------------
261
262 In order to prepare the API documentation, it is necessary to generate some
263 Web pages from the Python source code. For this, the epydoc application must
264 be available on your system. Then, inside the WebStack directory, run the
265 apidocs.sh tool script as follows:
266
267 ./tools/apidocs.sh
268
269 Some warnings may be generated by the script, but the result should be a new
270 apidocs directory within the WebStack directory.