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 Framework Support
12 -----------------
13
14 Currently, BaseHTTPRequestHandler (via BaseHTTPServer in the standard
15 library), CGI, Jython/Java Servlet API, mod_python, Twisted, Webware, WSGI
16 and Zope 2 are supported. Each framework has its own set of strengths and
17 weaknesses, but the idea is that deployment concerns can be considered
18 separately from the implementation of application functionality. Consult the
19 NOTES.txt files in each framework's subdirectory of the docs directory for
20 some notes on how applications may be run in each environment.
21
22 Tested Frameworks Release Information
23 ----------------- -------------------
24
25 BaseHTTPRequestHandler Python 2.2.2, Python 2.3.3
26 CGI Apache 2.0.44
27 Jython/Java Servlet API Jython 2.1, Java JDK 1.3.1_02, Tomcat 4.1.27 (Servlet 2.3)
28 mod_python 3.0.3 (3.1.3 for framework cookie and session support)
29 Twisted 1.0.5
30 Webware 0.8.1, CVS (2004-02-06)
31 WSGI PEP 333 (wsgiServer from WSGI Utils 0.2)
32 Zope 2.7.2-0
33
34 New in WebStack 0.8 (Changes since WebStack 0.7)
35 ------------------------------------------------
36
37 Added a standard exception, EndOfResponse, which can be used to immediately
38 stop the processing/production of a response; this is useful when resources
39 need to issue a redirect without unnecessary content being generated, for
40 example.
41 Fixed path information for Zope.
42 Added WSGI support.
43
44 New in WebStack 0.7 (Changes since WebStack 0.6)
45 ------------------------------------------------
46
47 Fixed path information semantics.
48 Fixed file upload semantics.
49 Fixed content type handling for Unicode output and for interpreting request
50 body fields/parameters (although some improvement remains).
51 Added a method to discover the chosen response stream encoding.
52 Fixed field/parameter retrieval so that path and body fields are distinct,
53 regardless of the framework employed.
54 Added a method to get a combination of path and body fields (suggested by Jacob
55 Smullyan).
56 Introduced Zope 2 support.
57 Improved Jython/Java Servlet API support (although a special PyServlet class
58 must now be used, and certain libraries must be deployed with applications).
59 Introduced authentication/authorisation support for Jython/Java Servlet API.
60 Session support has been added (except for Webware 0.8.1).
61 Alternative cookie support for mod_python has been added.
62 Cookie support now supports encoded Unicode sequences for names and values.
63
64 New in WebStack 0.6 (Changes since WebStack 0.5)
65 ------------------------------------------------
66
67 Introduced Jython/Java Servlet API support.
68 Minor fixes to example applications and to BaseHTTPRequestHandler.
69
70 New in WebStack 0.5 (Changes since WebStack 0.4)
71 ------------------------------------------------
72
73 Changed request body fields/parameters so that they are now represented using
74 Unicode objects rather than plain strings.
75 Introduced better support for Unicode in response streams.
76
77 New in WebStack 0.4 (Changes since WebStack 0.3)
78 ------------------------------------------------
79
80 Added application definition of user identity, permitting alternative
81 authentication mechanisms.
82 Improved BaseHTTPRequestHandler and mod_python reliability around fields from
83 request bodies.
84 Provided stream and environment parameterisation in the CGI adapter.
85 Added LoginRedirect and Login examples.
86 Added get_path_without_query and fixed get_path behaviour.
87
88 New in WebStack 0.3 (Changes since WebStack 0.2)
89 ------------------------------------------------
90
91 Added better header support for Webware (suggested by Ian Bicking).
92 Introduced CGI and Java Servlet support (the latter is currently
93 broken/unfinished).
94 Introduced support for cookies.
95
96 Future Work
97 -----------
98
99 Things to consider for future releases: improved cookie support, redirects,
100 access to shared resources and much better documentation.
101
102 Field access needs testing, especially for anything using the cgi.FieldStorage
103 class, and the way file uploads are exposed should be reviewed (currently the
104 meta-data is not exposed). The acquisition of fields from specific sources
105 should be tested with different request methods - some frameworks provide path
106 fields in the body fields dictionary, others (eg. Zope) change the fields
107 exposed depending on request method.
108
109 Interpretation of path field encodings needs to be verified. Currently, stray
110 path fields are handled (eg. in WebStack.Helpers.Request) as being ISO-8859-1,
111 but it might be the case that some such fields might be submitted as UTF-8.
112
113 Cookie objects need defining strictly, especially since the standard library
114 Cookie object behaves differently to mod_python (and possibly Webware) Cookie
115 objects. Moreover, the set_cookie_value method needs to provide access to the
116 usual cookie parameters as supported by the frameworks. The standard library
117 Cookie module has issues with Unicode cookie names (and possibly values) -
118 this is worked around, but it would be best to resolve this comprehensively.
119
120 UTF-16 (and possibly other encodings) causes problems with HTML form data sent
121 in POST requests using the application/x-www-form-urlencoded content type.
122 This should be reviewed at a later date when proper standardisation has taken
123 place.
124
125 Session support, especially through WebStack.Helpers.Session, should be
126 reviewed and be made compatible with non-cookie mechanisms.
127
128 The location of deployed applications in the filesystem should be exposed to
129 those applications.
130
131 Path information should be consistent across all frameworks, and the "path
132 info" value should be meaningful.
133
134 HeaderValue objects should be employed more extensively. Thus, the header
135 access methods may need to change their behaviour slightly.
136
137 Investigate the nicer functions in the cgi module, discarding the "magic"
138 stuff like FieldStorage.
139
140 The apidocs.py script needs finishing or a better documentation system needs
141 to be adopted.
142
143 Release Procedures
144 ------------------
145
146 Update the WebStack/__init__.py __version__ attribute.
147 Update the release notes (see above).
148 Check the setup.py file and ensure that all package directories are mentioned.
149 Tag, export.
150 Generate the PyServlet classes.
151 Archive, upload.