Old news archive

From now on SISCweb news items will be posted to the sourceforge.net project page in addition to the SISCweb site.

In order to keep complete records, the old news items are listed here.

24 Oct 2005: The Scheme Pet Store

Ben Simon has announced a Scheme Pet Store based on SISCweb. He relates his experience and design choices in a very nice writeup, and invites feedback from the Scheme community.
23 Oct 2005: Development branch in state of flux

The latest commits to the rel-0-3-dev branch implement: a) continuation persistence through Hibernate, b) a non-backwards-compatible context initialization sequence (not sure about this one yet), and c) grouping of continuations by request. The latter is necessary in order to expire at the same time closures generated within the same page through the @[href|src|action|data]-[p|c] attributes.

The build process at the moment requires some knowledge of hibernate. All the revisions prior to this commit are tagged as rel-0-3-dev-1 for those who are on the dev branch but would prefer to wait for this batch of changes to become more polished.

01 Aug 2005: v0.22 released

This release fixes a couple of bugs and completes the basic feature set introduced in the previous release.

Features:

* Added minimalistic shopping cart example to show a clean, stateful approach to the typical MVC pattern.
* SXML additions
o Deprecated @dispatch and @[href|src|action|data]-ce SXML attributes. The former is replaced by @href-p, and the latter are not needed because @[href|src|action|data]-c already encode the generated URL.
o The @bindings attribute can now be combined with @[href|src|action|data]-[p|c]; when left on its own, it will pass the specified bindings to the suspended continuation.
o Added *COMMENT* tag to SXML, converted to XML comments (<!-- -->)

The first two items make the extensions to the HTML markup complete in respect to basic flow control.
* Request forwarding functions can now pass along URLs to stored closures as bindings. This allows Servlet/JSPs to emulate some features more naturally available in SXML via the @[href|src|action|data]-[p|c] attributes.
* It is now possible to specify a global error handler that one can use to display the stack trace, etc.
* Initial support for PostgreSQL contributed by Ben Simon. Thank you!

Bug fixes:

* Bindings can now be used as objects across suspended continuations.
* Fixed date/time conversion bug between SQL and Scheme types.

Thanks to Ben Simon for spotting these two bugs and providing a fix to the latter.

10 Jul 2005: v0.21 released

This release fixes a few bugs and adds some features from the 0.3 development branch.

Features:

* Fixed various bugs and omissions in the @href-* attributes of the extended HTML.
* Patched a weird bug that seems to occur in Tomcat, sometimes causing sessions to be "lost" (not destroyed) after a server restart.
* Added @[href|src|action|data]-p HTML attributes to generate links to arbitrary closures. This extends and replaces the "dispatch" attribute, which will be deprecated in v0.3.
* The value #f for HTML elements or attributes values is now ignored. This is handy when generating content dynamically.
* Added Graphviz support through dot/neato/etc. executables and the DotML notation.
* DotML can also be embedded in a special HTML object element. The framework will either generate a GIF/JPG/PNG image or embed an SVG/etc. object. If the graph contains hyperlinks, an image map will also be generated. Hyperlinks can be specified as @href-[p|c|e|ce] and even use the k-url.
* Added Graphpad to siscweb-examples.war, a simple program to play with Graphviz.
* Updated the online documentation to reflect the new features in v0.21.

Known bugs:

* Locking problems with file-based HSQLDB when the appserver restarts the context. For now this can be circumvented by stopping and starting the context in separate steps.

19 Jun 2005: v0.2 released

This release extends SISCweb in several directions:

* New and old extensions to the SXML-based HTML are now implemented as new attributes of standard HTML tags.
* Added preliminary support for using JSPs or other traditional Java techniques instead of SXML for presentation.
* Continuations can now be stored in an HSQL or Oracle DB in addition to the session object. This approach is slower in small setups, but in time it should afford better scalability.
* Added unified interface to continuation persistence, so that other databases may be supported.
* A manual in progress can be found at: http://siscweb.sf.net/swm/swm.html
* Two new examples:
o a tic-tac-toe example written by Scott Miller, and
o a server-side, browser-based simple REPL that allows one to immediately send pages to the browser.
* Solved v0.1 bugs, as long as SISC v1.11 or later is used.
* Removed AspectJ requirement.
* Created home page: http://siscweb.sf.net/

Known bugs:

* Locking problems with file-based HSQLDB when the appserver restarts the context. For now this can be circumvented by stopping and starting the context in separate steps.

05 Apr 2005: v0.1 released

Features:

* Stateful web programming
* Server-side REPL
* SXML-based page generation
* Basic continuation storage in session

Known bugs:

* REPL doesn't quit if a user is connected when webserver stops, leaving the appserver process running
* Serialization problems when @url-dispatch is used