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