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