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