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Logging Capacity

The built-in capacity Logging provides tools for printing messages in the log associated to the agent.

1. Print an error or a warning message

For printing an error or a warning message, the two following functions are provided:

def error(message : Object, exception : Throwable = null, arguments : Object*)
def warning(message : Object, exception : Throwable = null, arguments : Object*)

The message parameter is converted to a string for obtaining the message to output. The message is built from the parsing of the message in which parameter constants aree replaced by the arguments. The exception parameter may be given for printing an exception that is the cause of the logging action.

Examples:

agent A {
	uses Logging
	def myaction {
		error("mymessage")
		error("mymessage", new Exception)
		warning("mymessage")
		warning("mymessage", new Exception)
	}
}

You could also give a text supplier, in the form of a lambda expression, to these logging functions in order to build the loggeable message dynamically.

agent A {
	uses Logging
	def myaction {
		error [ "mymessage" ]
		warning [ "mymessage" ]
	}
}

2. Print an information message

For printing an information message, the following function is provided:

def info(message : Object, arguments : Object*)

The message parameter is converted to a string for obtaining the message to output. The message is built from the parsing of the message in which parameter constants aree replaced by the arguments.

Example:

agent A {
	uses Logging
	def myaction {
		info("mymessage")
	}
}

You could also give a text supplier, in the form of a lambda expression, to the logging function in order to build the loggeable message dynamically.

agent A {
	uses Logging
	def myaction {
		info [ "mymessage" ]
	}
}

3. Print a debugging message

For printing a debugging message, the following function is provided:

def debug(message : Object, arguments : Object*)

The message parameter is converted to a string for obtaining the message to output. The message is built from the parsing of the message in which parameter constants aree replaced by the arguments.

Example:

agent A {
	uses Logging
	def myaction {
		debug("mymessage")
	}
}

You could also give a text supplier, in the form of a lambda expression, to the logging function in order to build the loggeable message dynamically.

agent A {
	uses Logging
	def myaction {
		debug [ "mymessage" ]
	}
}

4. Retrieve and change the logging level

The printable messages are associated to a level of logging (error, warning, info, debug). If a message is given to the logging system, and the current output level is lower than the message’s level, then the message is not output.

For retrieving the current logging level, the following function is provided:

def getLogLevel : int

The replied value is 0 when no message is printed, 1 if only error messages are printed, 2 for error and warning messages, etc.

For changing the current logging level, the following function is provided:

def setLogLevel(level : int)

Example:

agent A {
	uses Logging
	def myaction {
		var l = getLogLevel
		setLogLevel( l + 1 )
	}
}

5. Testing the logging level

The following functions permits testing if a specific logging level is enabled:

def isErrorLogEnabled : boolean
def isWarningLogEnabled : boolean
def isInfoLogEnabled : boolean
def isDebugLogEnabled : boolean

Example:

agent A {
	uses Logging
	def myaction : boolean {
		   isErrorLogEnabled
		|| isWarningLogEnabled
		|| isInfoLogEnabled
		|| isDebugLogEnabled
	}
}

6. Change the name of the logger

By default, the logging message contains the identifier of the agent associated to the Logging capacity.

Sometimes, it is helpful to change the printed name of the agent. The following function gives the opportunity to change this name.

def setLoggingName(name : String)

Example:

agent A {
	uses Logging
	def myaction {
		setLoggingName("the name of the agent")
	}
}

7. Accessing to the backend logger

The Logging capacity is based on the logging system of run-time virtual machine. The getLogger function provides you the access to the backend logger that is associated to the agent.

def getLogger : Logger

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