OriginUnknown/ChainOfResponsibility.html

## ChainOfResponsibility.html
<!doctype html>

<html lang="en">
<head>
    <title>Chain of Responsibility pattern</title>
</head>

<body>
<script type="text/javascript">
    /*
     * * Changelist - Chain of responsibility pattern 1.0.0.0 - first release, basic implementation
     * * Example based on Derek Banas' 'Chain of Responsibility' video. iHeartDerek!
     */

    //Request - is the desired action to be taken
    var requestObj = function ( num1, num2, cmd ) {
        return {
            "num1": num1,
            "num2": num2,
            "cmd": cmd //'add', 'sub', 'multi', 'div'
        }
    };

    /*
     * * Handler - processes the request passed to it.
     * * Handlers usually work to a 'Handler' interface which may have a 'successor' property which will store the next handler in the chain {object instance}
     * * and a 'handleRequest' method which is a class's implementation of how to handle the request passed to it.
     * * If the handler can handle the request it will, else will pass the request onto its successor for further handling
     */

    var Add = function () {
        var successor,
                setSuccessor = function ( nextInChain ) {
                    successor = nextInChain || null;
                },
                handleRequest = function ( request ) {
                    if ( request.cmd === 'add' ) {//if the request is to 'add', the Add handler will execute the request
                        console.log( request.num1 + " + " + request.num2 + " = " + (request.num1 + request.num2) );
                    } else if ( successor ) {//Otherwise, provided the successor has been set, call the handleRequest() method of that object next in the chain
                        successor.handleRequest( request );
                    }
                };
        return {
            "setSuccessor": setSuccessor,
            "handleRequest": handleRequest
        }
    };

    var Sub = function () {
        var successor,
                setSuccessor = function ( nextInChain ) {
                    successor = nextInChain || null;
                },
                handleRequest = function ( request ) {
                    if ( request.cmd === 'sub' ) {
                        console.log( request.num1 + " - " + request.num2 + " = " + (request.num1 - request.num2) );
                    } else if ( successor ) {
                        successor.handleRequest( request );
                    }
                };
        return {
            "setSuccessor": setSuccessor,
            "handleRequest": handleRequest
        }
    };

    var Multi = function () {
        var successor,
                setSuccessor = function ( nextInChain ) {
                    successor = nextInChain || null;
                },
                handleRequest = function ( request ) {
                    if ( request.cmd === 'multi' ) {
                        console.log( request.num1 + " * " + request.num2 + " = " + request.num1 * request.num2 );
                    } else if ( successor ) {
                        successor.handleRequest( request );
                    }
                };
        return {
            "setSuccessor": setSuccessor,
            "handleRequest": handleRequest
        }
    };

    var Divide = function () {
        var successor,
                setSuccessor = function ( nextInChain ) {
                    successor = nextInChain || null;
                },
                handleRequest = function ( request ) {
                    if ( request.cmd === 'div' ) {
                        console.log( request.num1 + " / " + request.num2 + " = " + request.num1 / request.num2 );
                    } else if ( successor ) {
                        successor.handleRequest( request );
                    } else {
                        console.log( "Unable to compute. Can only do addition, subtraction, multiplication and division." );
                    }
                };
        return {
            "setSuccessor": setSuccessor,
            "handleRequest": handleRequest
        }
    };

    /*
     * * Client
     * * 1. Create your objects for the chain
     */
    var step1 = Add(),
            step2 = Sub(),
            step3 = Multi(),
            step4 = Divide();

    //2. Organise the order of responsibility by setting the successor for each object
    step1.setSuccessor( step2 );
    step2.setSuccessor( step3 );
    step3.setSuccessor( step4 );

    //3. Create your requests
    var request1 = requestObj( 2, 2, 'add' );
    var request2 = requestObj( 96, 8, 'div' );
    var request3 = requestObj( 81, 19, 'sub' );
    var request4 = requestObj( 9, 9, 'multi' );
    var request5 = requestObj( 36, 6, 'sq' );

    //4. Start the chain
    step1.handleRequest( request1 );//returns 2 + 2 = 4
    step1.handleRequest( request2 );//returns 96 / 8 = 12
    step1.handleRequest( request3 );//returns 81 - 19 = 62
    step1.handleRequest( request4 );//returns 9 * 9 = 81
    step1.handleRequest( request5 );//returns "Unable to compute. Can only do addition, subtraction, multiplication and division."

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

	<html lang="en">
	<head>
	<title>Chain of Responsibility pattern</title>
	</head>

	<body>
	<script type="text/javascript">
	/*
	* * Changelist - Chain of responsibility pattern 1.0.0.0 - first release, basic implementation
	* * Example based on Derek Banas' 'Chain of Responsibility' video. iHeartDerek!
	*/

	//Request - is the desired action to be taken
	var requestObj = function ( num1, num2, cmd ) {
	return {
	"num1": num1,
	"num2": num2,
	"cmd": cmd //'add', 'sub', 'multi', 'div'
	}
	};

	/*
	* * Handler - processes the request passed to it.
	* * Handlers usually work to a 'Handler' interface which may have a 'successor' property which will store the next handler in the chain {object instance}
	* * and a 'handleRequest' method which is a class's implementation of how to handle the request passed to it.
	* * If the handler can handle the request it will, else will pass the request onto its successor for further handling
	*/

	var Add = function () {
	var successor,
	setSuccessor = function ( nextInChain ) {
	successor = nextInChain \|\| null;
	},
	handleRequest = function ( request ) {
	if ( request.cmd === 'add' ) {//if the request is to 'add', the Add handler will execute the request
	console.log( request.num1 + " + " + request.num2 + " = " + (request.num1 + request.num2) );
	} else if ( successor ) {//Otherwise, provided the successor has been set, call the handleRequest() method of that object next in the chain
	successor.handleRequest( request );
	}
	};
	return {
	"setSuccessor": setSuccessor,
	"handleRequest": handleRequest
	}
	};

	var Sub = function () {
	var successor,
	setSuccessor = function ( nextInChain ) {
	successor = nextInChain \|\| null;
	},
	handleRequest = function ( request ) {
	if ( request.cmd === 'sub' ) {
	console.log( request.num1 + " - " + request.num2 + " = " + (request.num1 - request.num2) );
	} else if ( successor ) {
	successor.handleRequest( request );
	}
	};
	return {
	"setSuccessor": setSuccessor,
	"handleRequest": handleRequest
	}
	};

	var Multi = function () {
	var successor,
	setSuccessor = function ( nextInChain ) {
	successor = nextInChain \|\| null;
	},
	handleRequest = function ( request ) {
	if ( request.cmd === 'multi' ) {
	console.log( request.num1 + " * " + request.num2 + " = " + request.num1 * request.num2 );
	} else if ( successor ) {
	successor.handleRequest( request );
	}
	};
	return {
	"setSuccessor": setSuccessor,
	"handleRequest": handleRequest
	}
	};

	var Divide = function () {
	var successor,
	setSuccessor = function ( nextInChain ) {
	successor = nextInChain \|\| null;
	},
	handleRequest = function ( request ) {
	if ( request.cmd === 'div' ) {
	console.log( request.num1 + " / " + request.num2 + " = " + request.num1 / request.num2 );
	} else if ( successor ) {
	successor.handleRequest( request );
	} else {
	console.log( "Unable to compute. Can only do addition, subtraction, multiplication and division." );
	}
	};
	return {
	"setSuccessor": setSuccessor,
	"handleRequest": handleRequest
	}
	};

	/*
	* * Client
	* * 1. Create your objects for the chain
	*/
	var step1 = Add(),
	step2 = Sub(),
	step3 = Multi(),
	step4 = Divide();

	//2. Organise the order of responsibility by setting the successor for each object
	step1.setSuccessor( step2 );
	step2.setSuccessor( step3 );
	step3.setSuccessor( step4 );

	//3. Create your requests
	var request1 = requestObj( 2, 2, 'add' );
	var request2 = requestObj( 96, 8, 'div' );
	var request3 = requestObj( 81, 19, 'sub' );
	var request4 = requestObj( 9, 9, 'multi' );
	var request5 = requestObj( 36, 6, 'sq' );

	//4. Start the chain
	step1.handleRequest( request1 );//returns 2 + 2 = 4
	step1.handleRequest( request2 );//returns 96 / 8 = 12
	step1.handleRequest( request3 );//returns 81 - 19 = 62
	step1.handleRequest( request4 );//returns 9 * 9 = 81
	step1.handleRequest( request5 );//returns "Unable to compute. Can only do addition, subtraction, multiplication and division."

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