title: Inserting a knockout computed observable in an observableArray that is generated with the ko.mapping plugin
body: <p>Is it possible to manually insert a computed observable into an array that is generated with the mapping plugin?  Here is an example that does not use the mapping plugin, but I would like to know if it could use it.</p>
  
  <p>Lets say I have JSON data from the server: </p>
  
  <pre><code>[{
      "OrderID":1,
      "FirstName":"Bill",
      "LastName":"Smith",
  },{
      "OrderID":2,
      "FirstName":"Jeff",
      "LastName":"Evans",
  }
  {
      "OrderID":3,
      "FirstName":"Dan",
      "LastName":"Johnson",
  }]
  </code></pre>
  
  <p>On my view I have an Order class and a view model:</p>
  
  <pre><code>function Order(order) {
    var self = this;
    self.OrderID = ko.observable(order.OrderID);
    self.FirstName = ko.observable(order.FirstName);
    self.LastName = ko.observable(order.LastName);
  
    /*This is what I want to insert after the mapping plugin 
    generates "orders on the ViewModel*/
    self.FullName = ko.computed(function () {
        return self.FirstName() + ' ' + self.LastName();
    });
  
  }
  
  function ViewModel() {
    var self = this;
    self.orders = ko.observableArray([])
  
  //Get orders
    $.ajax({
      url: '@Url.Action("orders")',
      type: "post",
      success: function (data) {
          var mappedOrders = $.map(data, function (item) { return new Order(item) });
          self.orders(mappedOrders);
       }
     })    
  }
  </code></pre>
  
  <p>Is it possible to use the mapping plugin to generate the orders array on the view model, and also be able to insert the computed observable "FullName" in the orders array?</p>