Examples of Using Method Tracking
For method tracking to be enabled, the following entry is made in the JADE initialization file used by the database server.
[JadeSecurity]
MethodTrackingEnabled = true
The following example initiates method tracking for a method defined on the Customer class, where the preamble and postamble methods are defined on the Process class in the same schema as the tracked method.
startTracking(targetProcess : Process);
vars
begin
targetProcess.startMethodTracking(Customer::getAddress,//tracked method
Process::beforeCall, //preamble method
Process::afterCall, //postamble method
targetProcess); //receiver
end;
In the following example, method tracking is initiated for a method defined in a different schema from where the preamble and postamble methods are defined. The Tracker class is defined within the user schema and the tracker parameter is a persistent instance of the Tracker class.
initiateTracking(targetProcess: Process, tracker: Tracker);
vars
scm : Schema;
cls : Class;
mth : Method;
begin
scm := rootSchema.getSchema("AcctSchema");
cls := scm.getClass("Customer");
mth := mth.getMethod("getAddress");
targetProcess.startMethodTracking(mth, //tracked method
Tracker::beforeCall, //preamble method
Tracker::afterCall, //postamble method
tracker); //receiver
end;
Define the preamble and postamble methods in the Tracker class. The afterCall postamble method in the following example uses simple write instructions to provide tracking information.
afterCall(paramList: ParamListType);
vars
status : Integer;
num, i : Integer;
begin
// Status information - Is this the preamble or postamble?
// Or has there been an exception?
status := process.getTrackedMethodStatus;
if status = 0 then write "no tracked method";
elseif status = 1 then write "in preamble method";
elseif status = 2 then write "in postamble method";
elseif status = 3 then write "exception occurred";
endif;
// Tracked method
write "tracked method: " & process.getTrackedMethod.name;
// Receiver
write "receiver: " & process.getTrackedMethodReceiver.String;
// Parameters
num := app.getParamListTypeLength(paramList);
foreach i in 1 to num do
write "parameter " & i.String & ": "
& app.getParamListTypeEntry(i, paramList).String;
endforeach;
// Return value
write "return value: " & process.getTrackedMethodReturnValue.String;
end;
