Knockoutjs.com - Templating example

http://knockoutjs.com/examples/templating.html

HTML

<div class='liveExample'> 
   <p style="color:red">How do I make this list unique?</p>
    <p>
    <select data-bind="options: uniqueCountries(), selectedOptions: selectedCountries" size="1" multiple="false" style="width:150px"></select>
  </p>
  <p style="color:red">And how do I filter the records below based on the selected items above? (multiple select)</p>
   <table style="width:300px">
     <thead>
       <th>Name</th>
       <th>Location</th>
     </thead>
    <tbody data-bind="foreach: filteredRecords()">
        <tr>
          <td>
                <span data-bind="text: name"> </span> 
          </td>
            <td>
                <span data-bind="text: country"> </span> 
          </td>
        </tr>
    </tbody>
  </table>

</div>
   <h2>Debug</h2>
<pre data-bind="text: ko.toJSON($root, null, 2)"></pre>

CSS

body { font-family: arial; font-size: 14px; }
.liveExample { padding: 1em; background-color: #EEEEDD; border: 1px solid #CCC; max-width: 655px; }
.liveExample input { font-family: Arial; }
.liveExample b { font-weight: bold; }
.liveExample p { margin-top: 0.9em; margin-bottom: 0.9em; }
.liveExample select[multiple] { width: 100%; height: 8em; }
.liveExample h2 { margin-top: 0.4em; }

.renderTime { color: #777; font-style: italic; font-size: 0.8em; }

li { list-style-type: disc; margin-left: 20px; }

JavaScript

// Define a "Person" class that tracks its own name and children, and has a method to add a new child
var Person = function(name, country) {
    this.name = name;
    this.country = country;
}

// The view model is an abstract description of the state of the UI, but without any knowledge of the UI technology (HTML)
var viewModel = {
    people: [
        new Person("Annabelle", "UK"),
        new Person("Bertie", "UK"),
       new Person("Bertie", "USA"),
        new Person("Ali", "Bangladesh"),
        new Person("Patel", "India"),
      new Person("Sweatha", "India"),
       new Person("Minto", "India"),
        ],
      selectedCountries: ko.observableArray(),
      uniqueCountries: function(){
            var countries =ko.utils.arrayMap(viewModel.people,function(person){
                return person.country;
            });
            return ko.utils.arrayGetDistinctValues(countries);
        },
        filteredRecords: function(){
            return ko.utils.arrayFilter(viewModel.people,function(person){
               return person.country == viewModel.selectedCountries(); 
            });
        }
};

ko.applyBindings(viewModel);