Brief summary of lectures - noerten/coursera-nodejs GitHub Wiki

Node Modules

• Each file in Node is its own module
• The module variable gives access to the current module definition in a file
• The module.exports variable determines the export from the current module
• The require function is used to import a module example

module.exports = function(x,y,callback) {
  try {
    if (x < 0 || y < 0) {
        throw new Error("Rectangle dimensions should be greater than zero: l = "
                            + x + ", and b = " + y);
    }
    else
         callback(null, {
            perimeter: function () {
        		   return (2*(x+y));
			},
            area:function () {
        		    return (x*y);
			}
    });
  }
  catch (error) {
        callback(error,null);
  }
}

var rect = require('./rectangle-2');

function solveRect(l,b) {
    console.log("Solving for rectangle with l = "
                + l + " and b = " + b);
    rect(l,b, function(err,rectangle) {
        if (err) {
	    console.log(err);
	}
	else {
	    console.log("The area of a rectangle of dimensions length = "
                 + l + " and breadth = " + b + " is " + rectangle.area());
            console.log("The perimeter of a rectangle of dimensions length = "
                 + l + " and breadth = " + b + " is " + rectangle.perimeter());
	}
    });
};