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, lighttpd 1.3.15
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 1.0 (Changes since WebStack 0.10)
55 -------------------------------------------------
56
57 Added Debian package support.
58
59 New in WebStack 0.10 (Changes since WebStack 0.9)
60 -------------------------------------------------
61
62 Changes to make the tools/demo.py script work on Windows (and other) platforms
63 (suggested by Jim Madsen).
64 Fixed end of header newlines for CGI (suggested by Matt Harrison).
65 Minor documentation fixes and improvements, adding information on AOLserver in
66 the CGI and Webware notes.
67 Changed the mod_python server name method to use the server object rather than
68 the connection object.
69 Added a parameter to the ResourceMap.MapResource class to permit automatic
70 redirects into resource hierarchies when no trailing "/" was given in the URL;
71 changed the updated virtual path info so that empty values may be set (the
72 guarantee that "/" will always appear no longer applies).
73 Fixed virtual path info retrieval when the value is an empty string.
74
75 New in WebStack 0.9 (Changes since WebStack 0.8)
76 ------------------------------------------------
77
78 Standardised error handling in the adapters so that tracebacks can be
79 suppressed and an internal server error condition raised.
80 Added overriding of path info in transactions.
81 Added a ResourceMap resource for dispatching to different resources
82 according to path components.
83 Standardised deployment for some frameworks (see docs/deploying.html).
84 Introductory documentation in XHTML format.
85 Added server name and port methods to the transaction.
86 Added a simple demonstration application, incorporating many of the examples
87 and launched under a single script.
88 Fixed mod_python native sessions.
89 Fixed Zope request stream access.
90 WebStack is now licensed under the LGPL - see docs/COPYING.txt for details.
91
92 New in WebStack 0.8 (Changes since WebStack 0.7)
93 ------------------------------------------------
94
95 Added a standard exception, EndOfResponse, which can be used to immediately
96 stop the processing/production of a response; this is useful when resources
97 need to issue a redirect without unnecessary content being generated, for
98 example.
99 Fixed path information for Zope.
100 Added WSGI support.
101 Verified Twisted 1.3.0 support with Python 2.3.3.
102
103 New in WebStack 0.7 (Changes since WebStack 0.6)
104 ------------------------------------------------
105
106 Fixed path information semantics.
107 Fixed file upload semantics.
108 Fixed content type handling for Unicode output and for interpreting request
109 body fields/parameters (although some improvement remains).
110 Added a method to discover the chosen response stream encoding.
111 Fixed field/parameter retrieval so that path and body fields are distinct,
112 regardless of the framework employed.
113 Added a method to get a combination of path and body fields (suggested by
114 Jacob Smullyan).
115 Introduced Zope 2 support.
116 Improved Jython/Java Servlet API support (although a special PyServlet class
117 must now be used, and certain libraries must be deployed with applications).
118 Introduced authentication/authorisation support for Jython/Java Servlet API.
119 Session support has been added (except for Webware 0.8.1).
120 Alternative cookie support for mod_python has been added.
121 Cookie support now supports encoded Unicode sequences for names and values.
122
123 New in WebStack 0.6 (Changes since WebStack 0.5)
124 ------------------------------------------------
125
126 Introduced Jython/Java Servlet API support.
127 Minor fixes to example applications and to BaseHTTPRequestHandler.
128
129 New in WebStack 0.5 (Changes since WebStack 0.4)
130 ------------------------------------------------
131
132 Changed request body fields/parameters so that they are now represented
133 using Unicode objects rather than plain strings.
134 Introduced better support for Unicode in response streams.
135
136 New in WebStack 0.4 (Changes since WebStack 0.3)
137 ------------------------------------------------
138
139 Added application definition of user identity, permitting alternative
140 authentication mechanisms.
141 Improved BaseHTTPRequestHandler and mod_python reliability around fields
142 from request bodies.
143 Provided stream and environment parameterisation in the CGI adapter.
144 Added LoginRedirect and Login examples.
145 Added get_path_without_query and fixed get_path behaviour.
146
147 New in WebStack 0.3 (Changes since WebStack 0.2)
148 ------------------------------------------------
149
150 Added better header support for Webware (suggested by Ian Bicking).
151 Introduced CGI and Java Servlet support (the latter is currently
152 broken/unfinished).
153 Introduced support for cookies.
154
155 Future Work
156 -----------
157
158 (Essential)
159
160 JythonServlet libraries need to be configured using sys.add_package when
161 these do not feature in the compiled-in list. Adding such configuration to
162 the handler may be most appropriate (since the web.xml file can be too
163 arcane), but this needs testing.
164
165 (Important)
166
167 Things to consider for future releases: improved cookie support, redirects,
168 access to shared resources and much better documentation.
169
170 Field access needs testing, especially for anything using the
171 cgi.FieldStorage class, and the way file uploads are exposed should be
172 reviewed (currently the meta-data is not exposed). The acquisition of fields
173 from specific sources should be tested with different request methods - some
174 frameworks provide path fields in the body fields dictionary, others (eg.
175 Zope) change the fields exposed depending on request method.
176
177 Interpretation of path field encodings needs to be verified. Currently,
178 stray path fields are handled (eg. in WebStack.Helpers.Request) as being
179 ISO-8859-1, but it might be the case that some such fields might be
180 submitted as UTF-8.
181
182 Cookie objects need defining strictly, especially since the standard library
183 Cookie object behaves differently to mod_python (and possibly Webware)
184 Cookie objects. Moreover, the set_cookie_value method needs to provide
185 access to the usual cookie parameters as supported by the frameworks. The
186 standard library Cookie module has issues with Unicode cookie names (and
187 possibly values) - this is worked around, but it would be best to resolve
188 this comprehensively.
189
190 UTF-16 (and possibly other encodings) causes problems with HTML form data
191 sent in POST requests using the application/x-www-form-urlencoded content
192 type. This should be reviewed at a later date when proper standardisation
193 has taken place.
194
195 Session support, especially through WebStack.Helpers.Session, should be
196 reviewed and be made compatible with non-cookie mechanisms.
197
198 HeaderValue objects should be employed more extensively. Thus, the header
199 access methods may need to change their behaviour slightly.
200
201 Investigate the nicer functions in the cgi module, discarding the "magic"
202 stuff like FieldStorage.
203
204 WSGI support could demand that a special "end of headers" method be
205 introduced into WebStack, thus making response output more efficient (and
206 probably also for other frameworks, too).
207
208 The algorithm employed in the WebStack.Helpers.Auth.get_token function
209 should be reviewed and improved for better security.
210
211 Investigate proper support for HEAD, OPTIONS and other request methods.
212
213 Consider packages for different operating systems.
214
215 (Completed/rejected)
216
217 The location of deployed applications in the filesystem should be exposed to
218 those applications. (This is actually available in the __file__ module
219 variable.)
220
221 Path information should be consistent across all frameworks, and the "path
222 info" value should be meaningful. (This should now be correct.)
223
224 Release Procedures
225 ------------------
226
227 Update the WebStack/__init__.py __version__ attribute.
228 Change the version number and package filename/directory in the documentation.
229 Change code examples in the documentation if appropriate.
230 Update the release notes (see above).
231 Check the setup.py file and ensure that all package directories are mentioned.
232 Tag, export.
233 Generate the PyServlet classes.
234 Generate the API documentation.
235 Remove generated .pyc files: rm `find . -name "*.pyc"`
236 Archive, upload.
237 Upload the introductory documentation.
238 Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.
239
240 Generating the API Documentation
241 --------------------------------
242
243 In order to prepare the API documentation, it is necessary to generate some
244 Web pages from the Python source code. For this, the epydoc application must
245 be available on your system. Then, inside the WebStack directory, run the
246 apidocs.sh tool script as follows:
247
248 ./tools/apidocs.sh
249
250 Some warnings may be generated by the script, but the result should be a new
251 apidocs directory within the WebStack directory.