ruby-on-rails – 如何将javascript对象的javascript值传递给rub

<%= javascript_include_tag "knockout-2.2.0","country-state" %>
<table>
    <thead>
        <tr>
            <th>Country</th>
            <th>State</th> 
            <th> </th>
        </tr>
    </thead>
    <tbody data-bind='foreach: lines'>
        <tr>
            <td>
                <select data-bind='options: sampleProductCategories,optionsText: "country",optionsCaption: "Select...",value: category'> </select>
            </td>
            <td data-bind="with: category">
                <select data-bind='options: products,value: $parent.product'> </select>
            </td>



            <td>
                <a href='#' data-bind='click: $parent.removeLine'>Remove</a>
            </td>
        </tr>
    </tbody>
</table>

<button data-bind='click: addLine'>Add</button>
<button data-bind='click: save'>Submit</button>

<script>
$(document).ready(function() {
function formatCurrency(value) {
    return "$" + value.toFixed(2);
}

var CartLine = function() {
    var self = this;
    self.category = ko.observable();
    self.product = ko.observable();

    self.subtotal = ko.computed(function() {
        return self.product() ? self.product().price * parseInt("0" + self.quantity(),10) : 0;
    });

    // Whenever the category changes,reset the product selection
    self.category.subscribe(function() {
        self.product(undefined);
    });
};

var Cart = function() {
    // Stores an array of lines,and from these,can work out the grandTotal
    var self = this;
    self.lines = ko.observableArray([new CartLine()]); // Put one line in by default
    self.grandTotal = ko.computed(function() {
        var total = 0;
        $.each(self.lines(),function() { total += this.subtotal() })
        return total;
    });

    // Operations
    self.addLine = function() { self.lines.push(new CartLine()) };
    self.removeLine = function(line) { self.lines.remove(line) };
    self.save = function() {
        var dataToSave = $.map(self.lines(),function(line) {
            return line.product() ? {
                state: line.product().country
            } : undefined
        });
        alert("Could now send this to server: " + JSON.stringify(dataToSave));
        $.ajax({
    url: '/employees/<%=@employee.id%>',dataType: 'json',async: false,method:'PUT',data:dataToSave,success: function(data) {

    }
    });
    };
};

ko.applyBindings(new Cart());
});
</script>

它在终端显示如

Started GET "/employees/1?undefined=undefined" for 127.0.0.1 at Mon Jan 21 13:36:15 +0530 2013
Processing by EmployeesController#show as JSON
  Parameters: {"id"=>"1","undefined"=>"undefined"}

如何将选定的州和国家作为json对象发送到控制器？