Using SISCweb in web applications is simple matter of including
its components in the classpath and making some entries in the
web.xml deployment descriptor.
First-time users may want to check out the example WAR file (siscweb-examples-[v].war). It can be deployed by simply dropping it into the deployment folder of a J2EE appserver, and can also be used as the starting point for developing a new application.
While the server-side REPL is disabled in the SISCweb examples WAR file available from sourceforge.net, if you build it from sources, a REPL will be bound to the localhost:5156 socket. This is a security vulnerability. You should make sure to disable this feature if you are concerned about other people on the same host gaining access to a full-fledged REPL.
SISCweb is divided into different components:
siscweb.jar. The desired components should be
placed in the context's WEB-INF/lib.
The SISC libraries, including the
sisc-heap.jar file, should be also added to
the load path. They are found in the SISC binary distribution.
Starting from SISCweb v0.5, the SISC libraries can be placed in a classpath common to multiple contexts (e.g. in an EAR root or in the application server's path).
The core siscweb.jar instead MUST be placed
in the context's WEB-INF/lib. While
SISCweb's critical data (e.g. the continuation table) is
per-context, the logger and the configuration settings
detailed below are (for now) in the Java static scope.
Beside SISCweb-specific settings, it is also possible to specify SISC parameters.
A Java adapter servlet allows the mapping of context paths to groups of sisclets. Sisclets are simply Scheme procedures associated through the publish mechanism (see Chapter 5, Publishing Procedures) to paths below that of the adapter servlet.
The adapter servlet accepts two parameters,
on-init-sexp and
on-destroy-sexp, which are invoked when the
servlet is initialized and destroyed. As the example below
shows, they are typically used to respectively publish and
unpublish sisclets.
<servlet>
<servlet-name>examples</servlet-name>
<description>siscweb examples</description>
<servlet-class>siscweb.web.SISCAdapterServlet</servlet-class>
<init-param>
<param-name>on-init-sexp</param-name>
<param-value>
<![CDATA[
;; NOTE: scm/ is not generally a good place, since it is browsable
(class-path-extension-append! '("scm/" "WEB-INF/scm/"))
(require-extension (lib siscweb/publish))
(require-extension (lib examples/hello-world))
(publish "/hello/*" 'hello-world)
;; replace round parentheses below with square ones in real life
))>
</param-value>
</init-param>
<init-param>
<param-name>on-destroy-sexp</param-name>
<param-value>
<![CDATA[
(require-extension (lib siscweb/publish))
(unpublish "/hello/*")
;; replace round parentheses with square in real life
))>
</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>examples</servlet-name>
<url-pattern>/sisclets/*</url-pattern>
</servlet-mapping>