/**
* forward an execute request a rule identified by its unique key
*
* @param key a string key identifying the rule instance to be fired
* @param recipient the recipient of the method from which execution of the rule was triggered or
* null if it was a static method
* @param args the arguments of the method from which execution of the rule was triggered
*/
public static void execute(String key, Object recipient, Object[] args) throws ExecuteException {
boolean enabled = isTriggeringEnabled();
if (!enabled) {
// we don't trigger code while we are doing rule housekeeping
return;
}
// disable triggering until we get into actual rule code
disableTriggersInternal();
try {
Rule rule = ruleKeyMap.get(key);
if (Transformer.isVerbose()) {
System.out.println("Rule.execute called for " + key);
}
// if the key is no longer present it just means the rule has been decommissioned so return
if (rule == null) {
if (Transformer.isVerbose()) {
System.out.println("Rule.execute for decommissioned key " + key);
}
return;
}
rule.execute(recipient, args);
} finally {
// restore the status quo -- we must have been enabled if we got to this method
enableTriggers();
}
}
public Object interpret(HelperAdapter helper) throws ExecuteException {
Object recipientValue = null;
try {
if (recipient != null) {
recipientValue = recipient.interpret(helper);
if (recipientValue == null) {
throw new ExecuteException(
"MethodExpression.interpret : null recipient for method "
+ token.getText()
+ getPos());
}
}
int argCount = arguments.size();
Object[] argValues = new Object[argCount];
for (int i = 0; i < argCount; i++) {
argValues[i] = arguments.get(i).interpret(helper);
}
// execute setTriggering directly rather than via reflection
// that way rule code switch off triggering for a rule injected
// into code used by Method.invoke()
if (method.equals(setTriggeringMethod)) {
boolean setting = (Boolean) argValues[0];
if (setting) {
Rule.enableTriggers();
} else {
Rule.disableTriggers();
}
return true;
}
// we have to enable triggers whenever we call out to a method in case it contians a trigger
// point
// TODO - do we do this if the method is a built-in? i.e. if the target is an instance of the
// helper class
// TODO - this breaks the user disable option so fix it!
Rule.enableTriggersInternal();
return method.invoke(recipientValue, argValues);
} catch (InvocationTargetException e) {
Throwable th = e.getCause();
if (th instanceof ExecuteException) {
throw (ExecuteException) th;
} else {
throw new ExecuteException(
"MethodExpression.interpret : exception invoking method " + token.getText() + getPos(),
th);
}
} catch (ExecuteException e) {
throw e;
} catch (Exception e) {
throw new ExecuteException(
"MethodExpression.interpret : exception invoking method " + token.getText() + getPos(),
e);
} finally {
// disable triggers again
Rule.disableTriggersInternal();
}
}