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