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, 1.3.0
30 Webware 0.8.1, CVS (2004-02-06)
31 WSGI run_with_cgi (PEP 333)
32 Zope 2.7.2-0
33
34 New in WebStack 0.9 (Changes since WebStack 0.8)
35 ------------------------------------------------
36
37 Standardised error handling in the adapters so that tracebacks can be
38 suppressed and an internal server error condition raised.
39 Added overriding of path info in transactions.
40 Added a ResourceMap resource for dispatching to different resources
41 according to path components.
42 Standardised deployment for some frameworks (see docs/DEPLOY.txt).
43
44 New in WebStack 0.8 (Changes since WebStack 0.7)
45 ------------------------------------------------
46
47 Added a standard exception, EndOfResponse, which can be used to immediately
48 stop the processing/production of a response; this is useful when resources
49 need to issue a redirect without unnecessary content being generated, for
50 example.
51 Fixed path information for Zope.
52 Added WSGI support.
53 Verified Twisted 1.3.0 support with Python 2.3.3.
54
55 New in WebStack 0.7 (Changes since WebStack 0.6)
56 ------------------------------------------------
57
58 Fixed path information semantics.
59 Fixed file upload semantics.
60 Fixed content type handling for Unicode output and for interpreting request
61 body fields/parameters (although some improvement remains).
62 Added a method to discover the chosen response stream encoding.
63 Fixed field/parameter retrieval so that path and body fields are distinct,
64 regardless of the framework employed.
65 Added a method to get a combination of path and body fields (suggested by Jacob
66 Smullyan).
67 Introduced Zope 2 support.
68 Improved Jython/Java Servlet API support (although a special PyServlet class
69 must now be used, and certain libraries must be deployed with applications).
70 Introduced authentication/authorisation support for Jython/Java Servlet API.
71 Session support has been added (except for Webware 0.8.1).
72 Alternative cookie support for mod_python has been added.
73 Cookie support now supports encoded Unicode sequences for names and values.
74
75 New in WebStack 0.6 (Changes since WebStack 0.5)
76 ------------------------------------------------
77
78 Introduced Jython/Java Servlet API support.
79 Minor fixes to example applications and to BaseHTTPRequestHandler.
80
81 New in WebStack 0.5 (Changes since WebStack 0.4)
82 ------------------------------------------------
83
84 Changed request body fields/parameters so that they are now represented using
85 Unicode objects rather than plain strings.
86 Introduced better support for Unicode in response streams.
87
88 New in WebStack 0.4 (Changes since WebStack 0.3)
89 ------------------------------------------------
90
91 Added application definition of user identity, permitting alternative
92 authentication mechanisms.
93 Improved BaseHTTPRequestHandler and mod_python reliability around fields from
94 request bodies.
95 Provided stream and environment parameterisation in the CGI adapter.
96 Added LoginRedirect and Login examples.
97 Added get_path_without_query and fixed get_path behaviour.
98
99 New in WebStack 0.3 (Changes since WebStack 0.2)
100 ------------------------------------------------
101
102 Added better header support for Webware (suggested by Ian Bicking).
103 Introduced CGI and Java Servlet support (the latter is currently
104 broken/unfinished).
105 Introduced support for cookies.
106
107 Future Work
108 -----------
109
110 (Essential)
111
112 JythonServlet libraries need to be configured using sys.add_package when
113 these do not feature in the compiled-in list. Adding such configuration to
114 the handler may be most appropriate (since the web.xml file can be too
115 arcane), but this needs testing.
116
117 (Important)
118
119 Things to consider for future releases: improved cookie support, redirects,
120 access to shared resources and much better documentation.
121
122 Field access needs testing, especially for anything using the cgi.FieldStorage
123 class, and the way file uploads are exposed should be reviewed (currently the
124 meta-data is not exposed). The acquisition of fields from specific sources
125 should be tested with different request methods - some frameworks provide path
126 fields in the body fields dictionary, others (eg. Zope) change the fields
127 exposed depending on request method.
128
129 Interpretation of path field encodings needs to be verified. Currently, stray
130 path fields are handled (eg. in WebStack.Helpers.Request) as being ISO-8859-1,
131 but it might be the case that some such fields might be submitted as UTF-8.
132
133 Cookie objects need defining strictly, especially since the standard library
134 Cookie object behaves differently to mod_python (and possibly Webware) Cookie
135 objects. Moreover, the set_cookie_value method needs to provide access to the
136 usual cookie parameters as supported by the frameworks. The standard library
137 Cookie module has issues with Unicode cookie names (and possibly values) -
138 this is worked around, but it would be best to resolve this comprehensively.
139
140 UTF-16 (and possibly other encodings) causes problems with HTML form data sent
141 in POST requests using the application/x-www-form-urlencoded content type.
142 This should be reviewed at a later date when proper standardisation has taken
143 place.
144
145 Session support, especially through WebStack.Helpers.Session, should be
146 reviewed and be made compatible with non-cookie mechanisms.
147
148 The location of deployed applications in the filesystem should be exposed to
149 those applications.
150
151 Path information should be consistent across all frameworks, and the "path
152 info" value should be meaningful.
153
154 HeaderValue objects should be employed more extensively. Thus, the header
155 access methods may need to change their behaviour slightly.
156
157 Investigate the nicer functions in the cgi module, discarding the "magic"
158 stuff like FieldStorage.
159
160 WSGI support could demand that a special "end of headers" method be
161 introduced into WebStack, thus making response output more efficient (and
162 probably also for other frameworks, too).
163
164 Release Procedures
165 ------------------
166
167 Update the WebStack/__init__.py __version__ attribute.
168 Update the release notes (see above).
169 Check the setup.py file and ensure that all package directories are mentioned.
170 Tag, export.
171 Generate the PyServlet classes.
172 Archive, upload.