OriginUnknown/CommandPattern.html

## CommandPattern.html
<!doctype html>

<html lang="en">
<head>
    <title>Command Pattern</title>
</head>

<body>
<script type="text/javascript">
    var _msg = "";

    //Receiver[s] -> classes that will carry out the action
    function Light () {
        var turnOnLight = function () {
            _msg = "The light is on";
            return _msg;
        };
        var turnOffLight = function () {
            _msg = "The light is on";
            return _msg;
        };
        //module pattern used to return the API for the Light method
        return {
            "turnOn" : turnOnLight,
            "turnOff" : turnOffLight
        }
    }

    //ConcreteCommand #1 -> implements the command interface by using the signature methods (execute and undo) to wrap the receiver's methods in
    var TurnLightsOnCommand = function () {
        var theLight = Light();
        var execute = function () {
            return theLight.turnOn();
        };
        var undo = function () {
            return theLight.turnOff();
        };
        //for the logging purposes
        var cmdName = function () {
            var fnName = "TurnLightsOnCommand";
            return fnName;
        };

        return {
            "execute" : execute,
            "undo" : undo,
            "getCmdName" : cmdName
        };
    };

    //ConcreteCommand #2
    var TurnLightsOffCommand = function () {
        var theLight = Light();
        var execute = function () {
            return theLight.turnOff();
        };
        var undo = function () {
            return theLight.turnOn();
        };
        //for the logging purposes
        var cmdName = function () {
            var fnName = "TurnLightsOffCommand";
            return fnName;
        };

        return {
            "execute" : execute,
            "undo" : undo,
            "getCmdName" : cmdName
        };
    };

    /*
    * * Invoker - triggers the execution of the command via the command object passed in.
    * * It also keeps a log of the commands issued and stores them into an array
    */
    var RemoteControl = function () {
        var commands = [], logger = StatusLogger();//private variables

        /*
        * * Like the ConcreteCommands, the Invoker uses the Command interface and therefore, expects the objects passed to
        * * it to have identical signature methods to the ones it's invoking
        */
        var onPress = function ( cmd ) {
            commands.push( cmd );
            cmd.execute();
            logger.add( cmd.getCmdName() + " has been executed." );
        };

        var onUndoPress = function ( cmd ) {
            commands.pop();
            cmd.undo();
            logger.add( cmd.getCmdName() + " has been undone." );
        };

        return {
            "press" : onPress,
            "undoPress" : onUndoPress,
            "logs" : logger.show
        };
    };

    //Helper function to show a list of commands that have been executed
    var StatusLogger = function () {
        var msg = "";
        var add = function ( m ) {
            msg += m + "\n";
        };
        var showMsg = function () {
            return msg;
        };

        return {
            "add" : add,
            "show" : showMsg
        };
    };

    //client
    //invokes the required command objects
    var switchOnLight = TurnLightsOnCommand();
    var switchOffLight = TurnLightsOffCommand();

    //gets the invoker class that will trigger the command requests
    var remoteControlDevice = RemoteControl();

    //pass the command objects to the invoker for execution
    remoteControlDevice.press( switchOnLight );
    remoteControlDevice.press( switchOffLight );
    remoteControlDevice.undoPress( switchOffLight );

    //get a list of the three commands that have been executed
    console.log( remoteControlDevice.logs() );

</script>
</body>
</html>
	<!doctype html>

	<html lang="en">
	<head>
	<title>Command Pattern</title>
	</head>

	<body>
	<script type="text/javascript">
	var _msg = "";

	//Receiver[s] -> classes that will carry out the action
	function Light () {
	var turnOnLight = function () {
	_msg = "The light is on";
	return _msg;
	};
	var turnOffLight = function () {
	_msg = "The light is on";
	return _msg;
	};
	//module pattern used to return the API for the Light method
	return {
	"turnOn" : turnOnLight,
	"turnOff" : turnOffLight
	}
	}

	//ConcreteCommand #1 -> implements the command interface by using the signature methods (execute and undo) to wrap the receiver's methods in
	var TurnLightsOnCommand = function () {
	var theLight = Light();
	var execute = function () {
	return theLight.turnOn();
	};
	var undo = function () {
	return theLight.turnOff();
	};
	//for the logging purposes
	var cmdName = function () {
	var fnName = "TurnLightsOnCommand";
	return fnName;
	};

	return {
	"execute" : execute,
	"undo" : undo,
	"getCmdName" : cmdName
	};
	};

	//ConcreteCommand #2
	var TurnLightsOffCommand = function () {
	var theLight = Light();
	var execute = function () {
	return theLight.turnOff();
	};
	var undo = function () {
	return theLight.turnOn();
	};
	//for the logging purposes
	var cmdName = function () {
	var fnName = "TurnLightsOffCommand";
	return fnName;
	};

	return {
	"execute" : execute,
	"undo" : undo,
	"getCmdName" : cmdName
	};
	};

	/*
	* * Invoker - triggers the execution of the command via the command object passed in.
	* * It also keeps a log of the commands issued and stores them into an array
	*/
	var RemoteControl = function () {
	var commands = [], logger = StatusLogger();//private variables

	/*
	* * Like the ConcreteCommands, the Invoker uses the Command interface and therefore, expects the objects passed to
	* * it to have identical signature methods to the ones it's invoking
	*/
	var onPress = function ( cmd ) {
	commands.push( cmd );
	cmd.execute();
	logger.add( cmd.getCmdName() + " has been executed." );
	};

	var onUndoPress = function ( cmd ) {
	commands.pop();
	cmd.undo();
	logger.add( cmd.getCmdName() + " has been undone." );
	};

	return {
	"press" : onPress,
	"undoPress" : onUndoPress,
	"logs" : logger.show
	};
	};

	//Helper function to show a list of commands that have been executed
	var StatusLogger = function () {
	var msg = "";
	var add = function ( m ) {
	msg += m + "\n";
	};
	var showMsg = function () {
	return msg;
	};

	return {
	"add" : add,
	"show" : showMsg
	};
	};

	//client
	//invokes the required command objects
	var switchOnLight = TurnLightsOnCommand();
	var switchOffLight = TurnLightsOffCommand();

	//gets the invoker class that will trigger the command requests
	var remoteControlDevice = RemoteControl();

	//pass the command objects to the invoker for execution
	remoteControlDevice.press( switchOnLight );
	remoteControlDevice.press( switchOffLight );
	remoteControlDevice.undoPress( switchOffLight );

	//get a list of the three commands that have been executed
	console.log( remoteControlDevice.logs() );

	</script>
	</body>
	</html>