Todos.js

/** 
*  * Todos.js
*   * contains a collection wrapper for the Todo model
*    */

// --- Data store
var _todos = [];

// --- Todo model
function Todo(name, done) { // function constructor, will be called by new Todo(xx, yy);
  this.name = name;
  this.done = done || false;
}
Todo.prototype.destroy = function() {
  var index = _todos.indexOf(this);
  _todos.splice(index, 1);
};
Todo.prototype.markAsDone = function() {
  this.done = true;
};
Todo.prototype.markAsNotDone = function() {
  this.done = false;
};

// --- Todos collection
var Todos = {
  getAll: function() {
    return _todos;
  },
  createTodo: function(name) {
    var todo = new Todo(name);
    _todos.push(todo);
    return todo;
  }
};

// --- Expose Todos. 
// If in node.js (or require.js), ```require('Todos.js')``` will return the Todos collection.
// If not, then Todos will be available as window.Todos
if (module && module.exports) {
  module.exports = Todos;
} else {
  window.Todos = Todos  
}

/* 
A better implementation will use the module pattern. 
So that only what we put in the export (or window) is reachable 
*/