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