如何扩展使用原型的JavaScript模块

Question

there is module which was implemented in specific JS file in my project like the following example

define("Company", ["exports", "Employee"], function(Employee) {
    function Company(name) {
        this.name = name;
        this.employees = [];
    };
    Company.prototype.addEmployee = function(name) {
        var employee = new Employee.Employee(name);
        this.employees.push(employee);
        employee.company = this;
    };
    exports.Company = Company;
});

Now In different JS file (new module) I want to extend addEmployee method, for example I want to add address data to it,is it possible??? if yes how should I do that ? example will be very helpful!

Thanks in advance!

Answer 1

If you want to change this method for one instance only what you can do is create a new instance of Company in your module, override addEmployee method on your instance by adding the code of your own, and than call the original method from prototype:

// create a new instance of Company
var myCompany = new Company('myCompany');
// add method 'addEmployee' to your instance, it will override original method
// you can, of course, add more arguments if you wish
myCompany.addEmployee = function(name) {
    // your code here
    // and than call the original method settings it's 'this' to 'this' of your instance, 
    // and providing appropriate arguments
    Company.prototype.addEmployee.call(this, name);
}

Answer 2

Does something like this work?

//required as Company
(function(){
  var addEmployee = Company.prototype.addEmployee;
  Company.prototype.addEmployee = function(name, address){
    //assuming the original addEmployee returns the created instance
    var emp = addEmployee.call(this,name);
    //do something with address
    emp.address=address;
    return emp;//also return the created employee so it'll behave the same as the original
  }
}())