Utility and convenience methods
CloverEnv
provides utility methods which can assist the API
programmer.
Log method
This method permits the API programmer to incorporate diagnostic or audit output in the output log of the system engine.
The log’s verbosity level is controlled at run-time without the Java API
programmer having to change code. The log
method has a
verbosity argument that determines whether it is actioned at run-time, depending on
environment and engine settings.
For example:
cloverEnv.log(50, "Message contents now >" +
msg.getContent() + "<");
This produces a line in the engine log similar to this, if the verbosity
environment is set for 50
or above:
23/04/09 16:52:05 - 50 - Message contents now >This is a message<
Tcl evaluation from Java
Tcl (Tool Command Language) is a richly-featured scripting language. This is the primary language used to write system UPoCs. Java API programmers can invoke a Tcl piece to take advantage of inbuilt Tcl functionality. Or, an existing Tcl procedure written for their site can be used.
Tcl works by evaluating commands that have zero or more arguments and optionally returning a value.
The tclEval
method of CloverEnv
requests the engine to evaluate a Tcl command and
returns any return value. Any error that is generated in the Tcl evaluation causes a
CloverleafException
to be thrown.