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/LICENCE.txt and docs/LICENCE-PyServlet.txt for more information.
30
31 Framework Support
32 -----------------
33
34 Currently, BaseHTTPRequestHandler (via BaseHTTPServer in the standard
35 library), CGI, Jython/Java Servlet API, mod_python, Twisted, Webware, WSGI
36 and Zope 2 are supported. Each framework has its own set of strengths and
37 weaknesses, but the idea is that deployment concerns can be considered
38 separately from the implementation of application functionality. Consult the
39 NOTES.txt files in each framework's subdirectory of the docs directory for
40 some notes on how applications may be run in each environment.
41
42 Tested Frameworks Release Information
43 ----------------- -------------------
44
45 BaseHTTPRequestHandler Python 2.2.2, Python 2.3.3, Python 2.4.1
46 CGI Apache 2.0.44, Apache 2.0.53, AOLserver 4.0.10
47 Jython/Java Servlet API Jython 2.1, Java JDK 1.3.1_02, Tomcat 4.1.27 (Servlet 2.3)
48 mod_python 3.0.3 (3.1.3 for framework cookie and session support)
49 Twisted 1.0.5, 1.3.0
50 Webware 0.8.1, CVS (2004-02-06)
51 WSGI run_with_cgi (PEP 333)
52 Zope 2.7.2-0, 2.8.0-final
53
54 New in WebStack 0.10 (Changes since WebStack 0.9)
55 -------------------------------------------------
56
57 Changes to make the tools/demo.py script work on Windows (and other) platforms
58 (suggested by Jim Madsen).
59 Fixed end of header newlines for CGI (suggested by Matt Harrison).
60 Minor documentation fixes and improvements, adding information on AOLserver in
61 the CGI and Webware notes.
62
63 New in WebStack 0.9 (Changes since WebStack 0.8)
64 ------------------------------------------------
65
66 Standardised error handling in the adapters so that tracebacks can be
67 suppressed and an internal server error condition raised.
68 Added overriding of path info in transactions.
69 Added a ResourceMap resource for dispatching to different resources
70 according to path components.
71 Standardised deployment for some frameworks (see docs/deploying.html).
72 Introductory documentation in XHTML format.
73 Added server name and port methods to the transaction.
74 Added a simple demonstration application, incorporating many of the examples
75 and launched under a single script.
76 Fixed mod_python native sessions.
77 Fixed Zope request stream access.
78 WebStack is now licensed under the LGPL - see docs/COPYING.txt for details.
79
80 New in WebStack 0.8 (Changes since WebStack 0.7)
81 ------------------------------------------------
82
83 Added a standard exception, EndOfResponse, which can be used to immediately
84 stop the processing/production of a response; this is useful when resources
85 need to issue a redirect without unnecessary content being generated, for
86 example.
87 Fixed path information for Zope.
88 Added WSGI support.
89 Verified Twisted 1.3.0 support with Python 2.3.3.
90
91 New in WebStack 0.7 (Changes since WebStack 0.6)
92 ------------------------------------------------
93
94 Fixed path information semantics.
95 Fixed file upload semantics.
96 Fixed content type handling for Unicode output and for interpreting request
97 body fields/parameters (although some improvement remains).
98 Added a method to discover the chosen response stream encoding.
99 Fixed field/parameter retrieval so that path and body fields are distinct,
100 regardless of the framework employed.
101 Added a method to get a combination of path and body fields (suggested by
102 Jacob Smullyan).
103 Introduced Zope 2 support.
104 Improved Jython/Java Servlet API support (although a special PyServlet class
105 must now be used, and certain libraries must be deployed with applications).
106 Introduced authentication/authorisation support for Jython/Java Servlet API.
107 Session support has been added (except for Webware 0.8.1).
108 Alternative cookie support for mod_python has been added.
109 Cookie support now supports encoded Unicode sequences for names and values.
110
111 New in WebStack 0.6 (Changes since WebStack 0.5)
112 ------------------------------------------------
113
114 Introduced Jython/Java Servlet API support.
115 Minor fixes to example applications and to BaseHTTPRequestHandler.
116
117 New in WebStack 0.5 (Changes since WebStack 0.4)
118 ------------------------------------------------
119
120 Changed request body fields/parameters so that they are now represented
121 using Unicode objects rather than plain strings.
122 Introduced better support for Unicode in response streams.
123
124 New in WebStack 0.4 (Changes since WebStack 0.3)
125 ------------------------------------------------
126
127 Added application definition of user identity, permitting alternative
128 authentication mechanisms.
129 Improved BaseHTTPRequestHandler and mod_python reliability around fields
130 from request bodies.
131 Provided stream and environment parameterisation in the CGI adapter.
132 Added LoginRedirect and Login examples.
133 Added get_path_without_query and fixed get_path behaviour.
134
135 New in WebStack 0.3 (Changes since WebStack 0.2)
136 ------------------------------------------------
137
138 Added better header support for Webware (suggested by Ian Bicking).
139 Introduced CGI and Java Servlet support (the latter is currently
140 broken/unfinished).
141 Introduced support for cookies.
142
143 Future Work
144 -----------
145
146 (Essential)
147
148 JythonServlet libraries need to be configured using sys.add_package when
149 these do not feature in the compiled-in list. Adding such configuration to
150 the handler may be most appropriate (since the web.xml file can be too
151 arcane), but this needs testing.
152
153 (Important)
154
155 Things to consider for future releases: improved cookie support, redirects,
156 access to shared resources and much better documentation.
157
158 Field access needs testing, especially for anything using the
159 cgi.FieldStorage class, and the way file uploads are exposed should be
160 reviewed (currently the meta-data is not exposed). The acquisition of fields
161 from specific sources should be tested with different request methods - some
162 frameworks provide path fields in the body fields dictionary, others (eg.
163 Zope) change the fields exposed depending on request method.
164
165 Interpretation of path field encodings needs to be verified. Currently,
166 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
167 ISO-8859-1, but it might be the case that some such fields might be
168 submitted as UTF-8.
169
170 Cookie objects need defining strictly, especially since the standard library
171 Cookie object behaves differently to mod_python (and possibly Webware)
172 Cookie objects. Moreover, the set_cookie_value method needs to provide
173 access to the usual cookie parameters as supported by the frameworks. The
174 standard library Cookie module has issues with Unicode cookie names (and
175 possibly values) - this is worked around, but it would be best to resolve
176 this comprehensively.
177
178 UTF-16 (and possibly other encodings) causes problems with HTML form data
179 sent in POST requests using the application/x-www-form-urlencoded content
180 type. This should be reviewed at a later date when proper standardisation
181 has taken place.
182
183 Session support, especially through WebStack.Helpers.Session, should be
184 reviewed and be made compatible with non-cookie mechanisms.
185
186 HeaderValue objects should be employed more extensively. Thus, the header
187 access methods may need to change their behaviour slightly.
188
189 Investigate the nicer functions in the cgi module, discarding the "magic"
190 stuff like FieldStorage.
191
192 WSGI support could demand that a special "end of headers" method be
193 introduced into WebStack, thus making response output more efficient (and
194 probably also for other frameworks, too).
195
196 The algorithm employed in the WebStack.Helpers.Auth.get_token function
197 should be reviewed and improved for better security.
198
199 Investigate proper support for HEAD, OPTIONS and other request methods.
200
201 Consider packages for different operating systems.
202
203 (Completed/rejected)
204
205 The location of deployed applications in the filesystem should be exposed to
206 those applications. (This is actually available in the __file__ module
207 variable.)
208
209 Path information should be consistent across all frameworks, and the "path
210 info" value should be meaningful. (This should now be correct.)
211
212 Release Procedures
213 ------------------
214
215 Update the WebStack/__init__.py __version__ attribute.
216 Change the version number and package filename/directory in the documentation.
217 Change code examples in the documentation if appropriate.
218 Update the release notes (see above).
219 Check the setup.py file and ensure that all package directories are mentioned.
220 Tag, export.
221 Generate the PyServlet classes.
222 Generate the API documentation.
223 Remove generated .pyc files: rm `find . -name "*.pyc"`
224 Archive, upload.
225 Upload the introductory documentation.
226 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
227
228 Generating the API Documentation
229 --------------------------------
230
231 In order to prepare the API documentation, it is necessary to generate some
232 Web pages from the Python source code. For this, the epydoc application must
233 be available on your system. Then, inside the WebStack directory, run the
234 apidocs.sh tool script as follows:
235
236 ./tools/apidocs.sh
237
238 Some warnings may be generated by the script, but the result should be a new
239 apidocs directory within the WebStack directory.