Introduction

------------

WebStack is a package which provides a common API for Python Web

applications, regardless of the underlying server or framework environment.

It should be possible with WebStack to design and implement an application,

to choose a deployment environment, and then to be able to deploy the

application in a different environment later on without having to go back

and rewrite substantial parts of the application.

Quick Start

-----------

Try running the demo:

python tools/demo.py

An introductory guide to creating applications can be found in the docs

directory - see docs/index.html for the start page.

Contact, Copyright and Licence Information

------------------------------------------

The current Web page for WebStack at the time of release is:

http://www.boddie.org.uk/python/WebStack.html

Copyright and licence information can be found in the docs directory - see

docs/LICENCE.txt and docs/LICENCE-PyServlet.txt for more information.

Framework Support

-----------------

Currently, BaseHTTPRequestHandler (via BaseHTTPServer in the standard

library), CGI, Jython/Java Servlet API, mod_python, Twisted, Webware, WSGI

and Zope 2 are supported. Each framework has its own set of strengths and

weaknesses, but the idea is that deployment concerns can be considered

separately from the implementation of application functionality. Consult the

NOTES.txt files in each framework's subdirectory of the docs directory for

some notes on how applications may be run in each environment.

Tested Frameworks           Release Information

-----------------           -------------------

BaseHTTPRequestHandler      Python 2.2.2, Python 2.3.3, Python 2.4.1

CGI                         Apache 2.0.44, Apache 2.0.53, AOLserver 4.0.10

Jython/Java Servlet API     Jython 2.1, Java JDK 1.3.1_02, Tomcat 4.1.27 (Servlet 2.3)

mod_python                  3.0.3 (3.1.3 for framework cookie and session support)

Twisted                     1.0.5, 1.3.0

Webware                     0.8.1, CVS (2004-02-06)

WSGI                        run_with_cgi (PEP 333)

Zope                        2.7.2-0, 2.8.0-final

New in WebStack 0.10 (Changes since WebStack 0.9)

-------------------------------------------------

Changes to make the tools/demo.py script work on Windows (and other) platforms

(suggested by Jim Madsen).

Fixed end of header newlines for CGI (suggested by Matt Harrison).

Minor documentation fixes and improvements, adding information on AOLserver in

the CGI and Webware notes.

Changed the mod_python server name method to use the server object rather than

the connection object.

Added a parameter to the ResourceMap.MapResource class to permit automatic

redirects into resource hierarchies when no trailing "/" was given in the URL;

changed the updated virtual path info so that empty values may be set (the

guarantee that "/" will always appear no longer applies).

Fixed virtual path info retrieval when the value is an empty string.

New in WebStack 0.9 (Changes since WebStack 0.8)

------------------------------------------------

Standardised error handling in the adapters so that tracebacks can be

suppressed and an internal server error condition raised.

Added overriding of path info in transactions.

Added a ResourceMap resource for dispatching to different resources

according to path components.

Standardised deployment for some frameworks (see docs/deploying.html).

Introductory documentation in XHTML format.

Added server name and port methods to the transaction.

Added a simple demonstration application, incorporating many of the examples

and launched under a single script.

Fixed mod_python native sessions.

Fixed Zope request stream access.

WebStack is now licensed under the LGPL - see docs/COPYING.txt for details.

New in WebStack 0.8 (Changes since WebStack 0.7)

------------------------------------------------

Added a standard exception, EndOfResponse, which can be used to immediately

stop the processing/production of a response; this is useful when resources

need to issue a redirect without unnecessary content being generated, for

example.

Fixed path information for Zope.

Added WSGI support.

Verified Twisted 1.3.0 support with Python 2.3.3.

New in WebStack 0.7 (Changes since WebStack 0.6)

------------------------------------------------

Fixed path information semantics.

Fixed file upload semantics.

Fixed content type handling for Unicode output and for interpreting request

body fields/parameters (although some improvement remains).

Added a method to discover the chosen response stream encoding.

Fixed field/parameter retrieval so that path and body fields are distinct,

regardless of the framework employed.

Added a method to get a combination of path and body fields (suggested by

Jacob Smullyan).

Introduced Zope 2 support.

Improved Jython/Java Servlet API support (although a special PyServlet class

must now be used, and certain libraries must be deployed with applications).

Introduced authentication/authorisation support for Jython/Java Servlet API.

Session support has been added (except for Webware 0.8.1).

Alternative cookie support for mod_python has been added.

Cookie support now supports encoded Unicode sequences for names and values.

New in WebStack 0.6 (Changes since WebStack 0.5)

------------------------------------------------

Introduced Jython/Java Servlet API support.

Minor fixes to example applications and to BaseHTTPRequestHandler.

New in WebStack 0.5 (Changes since WebStack 0.4)

------------------------------------------------

Changed request body fields/parameters so that they are now represented

using Unicode objects rather than plain strings.

Introduced better support for Unicode in response streams.

New in WebStack 0.4 (Changes since WebStack 0.3)

------------------------------------------------

Added application definition of user identity, permitting alternative

authentication mechanisms.

Improved BaseHTTPRequestHandler and mod_python reliability around fields

from request bodies.

Provided stream and environment parameterisation in the CGI adapter.

Added LoginRedirect and Login examples.

Added get_path_without_query and fixed get_path behaviour.

New in WebStack 0.3 (Changes since WebStack 0.2)

------------------------------------------------

Added better header support for Webware (suggested by Ian Bicking).

Introduced CGI and Java Servlet support (the latter is currently

broken/unfinished).

Introduced support for cookies.

Future Work

-----------

(Essential)

JythonServlet libraries need to be configured using sys.add_package when

these do not feature in the compiled-in list. Adding such configuration to

the handler may be most appropriate (since the web.xml file can be too

arcane), but this needs testing.

(Important)

Things to consider for future releases: improved cookie support, redirects,

access to shared resources and much better documentation.

Field access needs testing, especially for anything using the

cgi.FieldStorage class, and the way file uploads are exposed should be

reviewed (currently the meta-data is not exposed). The acquisition of fields

from specific sources should be tested with different request methods - some

frameworks provide path fields in the body fields dictionary, others (eg.

Zope) change the fields exposed depending on request method.

Interpretation of path field encodings needs to be verified. Currently,

stray path fields are handled (eg. in WebStack.Helpers.Request) as being

ISO-8859-1, but it might be the case that some such fields might be

submitted as UTF-8.

Cookie objects need defining strictly, especially since the standard library

Cookie object behaves differently to mod_python (and possibly Webware)

Cookie objects. Moreover, the set_cookie_value method needs to provide

access to the usual cookie parameters as supported by the frameworks. The

standard library Cookie module has issues with Unicode cookie names (and

possibly values) - this is worked around, but it would be best to resolve

this comprehensively.

UTF-16 (and possibly other encodings) causes problems with HTML form data

sent in POST requests using the application/x-www-form-urlencoded content

type.  This should be reviewed at a later date when proper standardisation

has taken place.

Session support, especially through WebStack.Helpers.Session, should be

reviewed and be made compatible with non-cookie mechanisms.

HeaderValue objects should be employed more extensively. Thus, the header

access methods may need to change their behaviour slightly.

Investigate the nicer functions in the cgi module, discarding the "magic"

stuff like FieldStorage.

WSGI support could demand that a special "end of headers" method be

introduced into WebStack, thus making response output more efficient (and

probably also for other frameworks, too).

The algorithm employed in the WebStack.Helpers.Auth.get_token function

should be reviewed and improved for better security.

Investigate proper support for HEAD, OPTIONS and other request methods.

Consider packages for different operating systems.

(Completed/rejected)

The location of deployed applications in the filesystem should be exposed to

those applications. (This is actually available in the __file__ module

variable.)

Path information should be consistent across all frameworks, and the "path

info" value should be meaningful. (This should now be correct.)

Release Procedures

------------------

Update the WebStack/__init__.py __version__ attribute.

Change the version number and package filename/directory in the documentation.

Change code examples in the documentation if appropriate.

Update the release notes (see above).

Check the setup.py file and ensure that all package directories are mentioned.

Tag, export.

Generate the PyServlet classes.

Generate the API documentation.

Remove generated .pyc files: rm `find . -name "*.pyc"`

Archive, upload.

Upload the introductory documentation.

Update PyPI, PythonInfo Wiki, Vaults of Parnassus entries.

Generating the API Documentation

--------------------------------

In order to prepare the API documentation, it is necessary to generate some

Web pages from the Python source code. For this, the epydoc application must

be available on your system. Then, inside the WebStack directory, run the

apidocs.sh tool script as follows:

./tools/apidocs.sh

Some warnings may be generated by the script, but the result should be a new

apidocs directory within the WebStack directory.