Question

I am trying to reuse the same form for adding and editing employee information. I am using knockout js and on my view I make the knockout model:

var koModel = new EmployeeModel(div);

and if I want to populate the fields from the server I want to do something like this:

var koModel = new EmployeeModel(unserializedModelFromController, div);

I was wondering what is the best way to distinguish if the request is for a new employee or if it is to edit an existing employee.

Answer 1

If you turn your parameters around you can write a single constructor function.

var EmployeeModel = function(div, model) {
  if (model) {
    // Existing model has been passed, it's an edit request
  } else {
    // No model has been passed, it's a new request
  }
}

This can be called like:

new EmployeeModel(div);

or

new EmployeeModel(div, model);